Tin-antimony babbitt (tin-base bearing metal) Sn-Sb-Cu
Tin-base babbitt ASTM B23 Grade 2: Sn 89, Sb 7.5, Cu 3.5 nominal (mass %), limits Sn 88 to 90, Sb 7 to 8, Cu 3 to 4, Pb up to 0.35. Lead-based babbitt BS 3332 Alloy G: Pb balance, Sn 4.5 to 6.5, Sb 14 to 17 (mass %). Pewter: tin 85 to 99, antimony about 5 to 10, copper about 2 (mass %)
Also known as ASTM B23
Tin-base babbitt is a soft alloy of tin with about 7.5% antimony and 3.5% copper (ASTM B23 Grade 2, nominal 89% tin).
Evidence level
2 of 5
Lab-measured
- 0Predicted only. No one has made it, or no measurement exists.
- 1Calculated. Only calculated or predicted values from sources.
- 2Lab-measured. Measured properties with their conditions stated.
- 3Space-relevant tests. Measured in conditions relevant to space, such as vacuum or atomic oxygen.
- 4Ground-qualified. Qualified for an application on the ground.
- 5Flown or field-proven. Flight or field results exist.
Melt range
241 to 354 degC
Hardness
24.5 HB
Stiffness
52 GPa
Fatigue
33 MPa
Recipe, share of the weight
- Sn 89%Tin
- Sb 7.5%Antimony
- Cu 3.5%Copper
Best for
Thin plain-bearing linings that must tolerate repeated loading: Wikipedia says combustion engines use tin-based babbitt because it withstands cyclic loading
Weakest at
Strength and temperature: a solidus of 241 degC, a Brinell hardness of 24.5 and 42.1 MPa compressive yield. Tin pest and antimony toxicity add cold and handling limits.
Risk at a glance
- People None found. Hazard codes apply to the elements
- If it fails High. Overheating of the bearing lining
- Corrosion Moderate. At and below 13.2 degC, white tin can change to grey tin with a volume increase of about 27%.
Quick facts: Sn-Sb-Cu
| Property | Value | Basis |
|---|---|---|
| Density | 6.68 to 7.39 g/cm³ | 2 sourced values across conditions |
| Tensile strength | 77 to 87 MPa | 2 sourced values across conditions |
| Young's modulus | 52 GPa | 1 sourced value |
| Hardness (Brinell) | 24.5 HB | 1 sourced value |
| Melting point | 232 to 630 °C | 2 sourced values across conditions |
What is the density of Tin-antimony babbitt (Sn-Sb-Cu)?
Tin-antimony babbitt (Sn-Sb-Cu) has a density of 6.68 to 7.39 g/cm³. The range covers 2 sourced values across the tempers, forms and test conditions the sources report; room-temperature values are used where a source states a temperature.
What is the melting point of Tin-antimony babbitt (Sn-Sb-Cu)?
Tin-antimony babbitt (Sn-Sb-Cu) has a melting point of 232 to 630 °C. The range covers 2 sourced values across the tempers, forms and test conditions the sources report; room-temperature values are used where a source states a temperature.
What is the tensile strength of Tin-antimony babbitt (Sn-Sb-Cu)?
Tin-antimony babbitt (Sn-Sb-Cu) has a tensile strength of 77 to 87 MPa. The range covers 2 sourced values across the tempers, forms and test conditions the sources report; room-temperature values are used where a source states a temperature.
What is the Young's modulus of Tin-antimony babbitt (Sn-Sb-Cu)?
Tin-antimony babbitt (Sn-Sb-Cu) has a Young's modulus of 52 GPa. The source and test conditions are listed in the properties table on this page.
What is the hardness of Tin-antimony babbitt (Sn-Sb-Cu)?
Tin-antimony babbitt (Sn-Sb-Cu) has a Brinell hardness of 24.5 HB. The source and test conditions are listed in the properties table on this page.
What is Tin-antimony babbitt (Sn-Sb-Cu) used for?
Uses recorded in the sources include Engine plain bearings (tin-based babbitt); Bearing metals, bronze and brass (babbitt, tinning); Solder.
Why it exists
Tin-base babbitt is a soft tin alloy with about 7.5% antimony and 3.5% copper. It is used as a thin running surface in plain bearings. The ASTM B23 Grade 2 grade has a density of 7.39 g/cm3, a solidus of 241 degC and a liquidus of 354 degC, and a Brinell hardness of 24.5 with a 10 mm ball and a 500 kg load. Its tensile strength is 77 MPa when chill cast. Wikipedia describes babbitt as a thin surface layer in a multi-metal bearing and says combustion engines use tin-based babbitt because it tolerates cyclic loading. Pure tin melts at 231.9 degC, so the babbitt starts to melt at a higher temperature than the pure metal.
Where it's used
Engine bearings
Internal combustion engines use babbitt that is primarily tin-based because it can withstand cyclic loading (Wikipedia). Poured babbitt bearings were common in cars until the mid-1950s.
Bearing metals, solder and tinning
Babbitt, brass and bronze, and tinning together took 7% of U.S. tin use in 2025, and solder took 11% (USGS).
Lead-acid batteries (antimony)
Antimonial lead and ammunition took 40% of U.S. antimony use in 2025, and secondary antimony was intended for the lead-acid battery industry (USGS).
Recipe
Tin-base babbitt ASTM B23 Grade 2: Sn 89, Sb 7.5, Cu 3.5 nominal (mass %), limits Sn 88 to 90, Sb 7 to 8, Cu 3 to 4, Pb up to 0.35. Lead-based babbitt BS 3332 Alloy G: Pb balance, Sn 4.5 to 6.5, Sb 14 to 17 (mass %). Pewter: tin 85 to 99, antimony about 5 to 10, copper about 2 (mass %); typical European casting pewter Sn 94, Cu 1, Sb 5.
Tin-base babbitt (ASTM B23 Grade 2) is a tin alloy with about 7.5% antimony and 3.5% copper. The nominal composition is 89% tin, 7.5% antimony and 3.5% copper, within limits of 88 to 90% tin, 7 to 8% antimony and 3 to 4% copper, with lead at or below 0.35%.
| Ingredient | Share of the weight | What it does |
|---|---|---|
| Tin Sn | 89% | The base metal, 88 to 90% of the alloy by the datasheet limits. |
| Antimony Sb | 7.5% | The main alloying addition, limit 7 to 8%. |
| Copper Cu | 3.5% | A second alloying addition, limit 3 to 4%. |
Weight shares are as printed in the sources.
What it can do
Melt range
241 to 354 degC
measured
The tin-base babbitt starts to melt at 241 degC and is fully liquid at 354 degC (Kapp). Pure tin melts at 231.9 degC.
Hardness
24.5 HB
measured
Brinell hardness is 24.5 at a 500 kg load with a 10 mm ball (Kapp). Chill cast, the tensile strength is 77 MPa.
Stiffness
52 GPa
measured
The tensile elastic modulus is 52 GPa for the alloy cast at 400 degC into a 100 degC mold (Kapp).
Fatigue
33 MPa
measured
Kapp gives a fatigue strength of 33 MPa at 2 x 10^7 cycles in an R.R. Moore test.
How it compares
The babbitt starts to melt at 241 degC, above pure tin at 231.9 degC, and well below antimony metal at 630 degC. It is denser than antimony (7.39 against 6.68 g/cm3). The rows below compare the babbitt with those reference values.
The same measurements for each material, so you can compare them. Each row names the key condition under the value; the full conditions and methods are in the numbered notes under Technical details. Other materials are shown beside it; each was measured under its own conditions, so open its page before comparing closely. Compare every grade in the family.
| Measurement | Sn-Sb-Cu | Sn | Pb | Bi | In | Cd | Sb | Pb-Sb | SnPb | SAC305 | - | - | GaInSn | In-Sn / In-Ag | SnZn and SnBi | Pb alloys |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Thermal behavior and safety | ||||||||||||||||
| Solidus to liquidus range, tin-base babbitt | 241 to 354 °C2 | 231.9 °C | 327.5 °C | 271.3 °C | 156.6 °C | 321 °C | 630.7 °C | 630 °C | 183 °C | 217 °C | 70 °C | 98 °C | -19 °C | 118 °C | 199 °C | 179 °C |
| Melting point of pure tin, for comparison with the babbitt | 231.9 °C11 | 231.9 °C | 327.5 °C | 271.3 °C | 156.6 °C | 321 °C | 630.7 °C | 630 °C | 183 °C | 217 °C | 70 °C | 98 °C | -19 °C | 118 °C | 199 °C | 179 °C |
| Melting point of antimony metal, the alloying element | 630 °C14 | 231.9 °C | 327.5 °C | 271.3 °C | 156.6 °C | 321 °C | 630.7 °C | 630 °C | 183 °C | 217 °C | 70 °C | 98 °C | -19 °C | 118 °C | 199 °C | 179 °C |
| Lifetime and stability | ||||||||||||||||
| Volume increase, white tin to grey tin | 27 %13 | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data |
| Physical and electrical | ||||||||||||||||
| Density of tin-base babbitt, ASTM B23 Grade 2 | 7.39 g/cm³1 | 7310 kg/m3 | 11.34 g/cm³ | 9.78 g/cm³ | 7.31 g/cm³ | 8.69 g/cm³ | 6.68 g/cm³ | 6.68 g/cm³ | 8.4 g/cm³ | 7.35 g/cc | 10.15 g/cm³ | 10.44 g/cm³ | 6.44 g/cm³ | 7.3 g/cm³ | 7.27 g/cc | 11.28 - |
| Brinell hardness, tin-base babbitt | 24.5 HB3 | no data | 38.3 MN/m2 | no data | 8.83 MN/m2 | 203 MN/m2 | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data |
| Density of antimony metal, the alloying element | 6.68 g/cm³15 | 7310 kg/m3 | 11.34 g/cm³ | 9.78 g/cm³ | 7.31 g/cm³ | 8.69 g/cm³ | 6.68 g/cm³ | 6.68 g/cm³ | 8.4 g/cm³ | 7.35 g/cc | 10.15 g/cm³ | 10.44 g/cm³ | 6.44 g/cm³ | 7.3 g/cm³ | 7.27 g/cc | 11.28 - |
| Temperature behavior | ||||||||||||||||
| Tin pest transition, white tin to grey tin | 13.2 °C12 | 13.2 °C | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data |
| Other measurements | ||||||||||||||||
| Ultimate tensile strength, chill cast at 20 degC | 77 MPa4 | no data | no data | no data | 2.6 to 4.5 MPa | no data | no data | 34.8 to 38.9 MPa | 43 MPa | 39.58 MPa | no data | 44.1 MPa | no data | 12 MPa | 54.7 MPa | 43 MPa |
| Ultimate tensile strength, die cast | 87 MPa5 | no data | no data | no data | 2.6 to 4.5 MPa | no data | no data | 34.8 to 38.9 MPa | 43 MPa | 39.58 MPa | no data | 44.1 MPa | no data | 12 MPa | 54.7 MPa | 43 MPa |
| Elongation at break, chill cast (Kapp) | 18 %6 | no data | no data | no data | no data | no data | no data | 7.2 to 8.2 % | 40 % | 49 % | no data | 37.5 % | no data | no data | 32.5 % | 40 % |
| Elongation, ASTM B23 Grade 2 datasheet (Trotter) | 8 %7 | no data | no data | no data | no data | no data | no data | 7.2 to 8.2 % | 40 % | 49 % | no data | 37.5 % | no data | no data | 32.5 % | 40 % |
| Tensile elastic modulus, cast tin-base babbitt | 52 GPa8 | 50 GPa | no data | 32 GPa | 11 GPa | 50 GPa | 54.7 GPa | no data | no data | 6.9 GPa | 12.7 GPa | no data | no data | no data | no data | no data |
| Fatigue strength, chill cast tin-base babbitt | 33 MPa9 | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data |
| Compressive yield strength, tin-base babbitt | 42.1 MPa10 | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data | no data |
Why choose it, and why not
Good for
- Thin plain-bearing linings: the Kapp datasheet gives a Brinell hardness of 24.5 and a tensile strength of 77 MPa when chill cast.
- Engine bearings: Wikipedia says tin-based babbitt is used in combustion engines because it withstands cyclic loading.
Watch out for
- Melting range: the babbitt begins to melt at 241 degC, well below the 630 degC melting point of antimony metal.
- Elongation differs by source (18% on Kapp, 8.0% on Trotter) and the Trotter figure has no test conditions.
- Tin pest: below 13.2 degC, white tin can change to grey tin with a volume increase of about 27%; no test on the alloy was found.
- Antimony and lead carry serious PubChem hazard codes; the babbitt itself has no hazard data in the sources read.
Tin-base babbitt is a soft, low-melting bearing alloy with a solidus of 241 degC, a Brinell hardness of 24.5 and a 77 MPa chill-cast tensile strength. Its uses are in engine bearings and as a bearing metal. Its weak points are the low melting range, the cold change of tin, and the absence of test data on corrosion, ageing and space environments. Elongation values disagree between datasheets.
Technical details
For scientists and researchers. Everything above comes from the record below: every number with its method, its conditions and its source.
Other names and standards
The same grade under other systems, as datasheets and standards print them. Each code was checked against the page it comes from.
| System | Codes |
|---|---|
| ASTM | B23 |
Notes
The method, full conditions and any caveat for the numbered rows above.
| # | Measurement | Method | Conditions | Caveat |
|---|---|---|---|---|
| 1 | Density of tin-base babbitt, ASTM B23 Grade 2 | Value printed on the Kapp Alloy product page. The same page also prints the unit as mg/m3 once, which is a misprint. | composition ASTM B23 Grade 2, nominal Sn 89 / Sb 7.5 / Cu 3.5 (mass %)temperature not stated | — |
| 2 | Solidus to liquidus range, tin-base babbitt | Range printed on the Kapp Alloy product page; the Trotter datasheet prints the same 466 and 669 degF as solidus and liquidus. | basis printed as 466-669 degF (241-354 °C)composition ASTM B23 Grade 2 | — |
| 3 | Brinell hardness, tin-base babbitt | Value printed on the Kapp Alloy product page with its test conditions | ball 10 mmload 500 kgtime 30 scomposition ASTM B23 Grade 2 | The name brinell_hardness is not in spores/property-canon.yaml and is used as it is. |
| 4 | Ultimate tensile strength, chill cast at 20 degC | Value in the chill-cast table of the Kapp Alloy product page | casting chill casttemperature 20 °C (68 degF)composition ASTM B23 Grade 2 | — |
| 5 | Ultimate tensile strength, die cast | Value printed on the Kapp Alloy product page, footnote and die-cast entry | casting die cast, poured at 600 degF (315 °C) into a 302 degF (150 °C) moldcomposition ASTM B23 Grade 2 | — |
| 6 | Elongation at break, chill cast (Kapp) | Value printed on the Kapp Alloy product page, chill-cast entry | casting chill casttemperature 20 °Cgage 4 x (area)^1/2 gage length | — |
| 7 | Elongation, ASTM B23 Grade 2 datasheet (Trotter) | Value printed on the Nathan Trotter Grade 2 datasheet. It is lower than the chill-cast figure from Kapp, and the two sheets do not give matching test conditions. | basis product data sheet, no test condition printedcomposition ASTM B23 Grade 2 | — |
| 8 | Tensile elastic modulus, cast tin-base babbitt | Value in the mechanical properties table of the Kapp Alloy product page | test tensioncasting cast at 400 °C into a 100 °C mold | — |
| 9 | Fatigue strength, chill cast tin-base babbitt | Value printed on the Kapp Alloy product page, fatigue entry | test R.R. Moorecycles 2 x 10^7 (printed as 2 x 107)casting chill cast | — |
| 10 | Compressive yield strength, tin-base babbitt | Value printed on the Kapp Alloy product page, compressive entry | set 0.125% setcomposition ASTM B23 Grade 2 | The name compressive_yield_strength is not in spores/property-canon.yaml and is used as it is. |
| 11 | Melting point of pure tin, for comparison with the babbitt | Value listed in the melting point section of the PubChem record for tin | form pure tinpressure not stated | — |
| 12 | Tin pest transition, white tin to grey tin | Value printed in the allotropic transformation section of Wikipedia Tin pest | transformation white (beta) tin to grey (alpha) tin, at and below the temperaturebasis pure tin; the babbitt alloy is not tested | The name allotropic_transformation_temperature is not in spores/property-canon.yaml and is used as it is. |
| 13 | Volume increase, white tin to grey tin | Value printed in the allotropic transformation section of Wikipedia Tin pest | basis change from white (beta) to grey (alpha) tincomposition pure tin | — |
| 14 | Melting point of antimony metal, the alloying element | Value listed in the melting point section of the PubChem record for antimony | form antimony metalpressure not stated | — |
| 15 | Density of antimony metal, the alloying element | Value printed in the density section of the PubChem record for antimony | temperature 20 °Cform antimony metal | — |
Corrosion and compatibility
What happens when it meets other materials and environments.
| Environment | Concern | What happens |
|---|---|---|
| Below 13.2 degC, pure tin | moderate | At and below 13.2 degC, white tin can change to grey tin with a volume increase of about 27%.1 |
| # | Environment | Details | Test conditions |
|---|---|---|---|
| 1 | Below 13.2 degC, pure tin | Wikipedia gives 13.2 degC as the temperature at and below which the change happens. It says the change is slow to start because of a high activation energy and then speeds up, and it gives a volume increase of about 27%. No rate test on the babbitt alloy was found. | basis pure tin; alloy behaviour not stated in the sourcecondition temperature at or below 13.2 °C |
Risks and side effects
Hazards to people, what happens when a cell overheats, and how the material is handled and stored.
For people
The babbitt is mostly tin, but the PubChem notifications for antimony and lead carry serious hazard codes.
- Antimony
- PubChem notifications for antimony metal give H301 at 18.2%, H332 at 26.9% and H351 (suspected of causing cancer) at 31.8%, with signal word Danger.
- Lead
- PubChem notifications for lead give H360 at 84.4%, which covers harm to fertility or the unborn child, and H372 at 50.5%.
- Tin
- PubChem notifications for tin give H319 at 24.2% and H335 at 23.1%. A further notification gives H372.
If the lining overheats
The melting range of the babbitt and the cold change of tin are the two temperature limits the sources give.
- Melting range
- The Kapp datasheet gives a solidus of 241 degC and a liquidus of 354 degC. The alloy starts to melt at the solidus, so its strength falls before the liquidus.
- Tin pest
- Wikipedia gives 13.2 degC as the temperature at and below which white tin changes to grey tin, with a volume increase of about 27%.
Handling and storage
The sources read give no handling advice for the babbitt grade itself.
- Safety data
- Check the supplier's safety data sheet for the grade you buy. The PubChem codes above belong to the elements.
Test details
The original wording and numbers from the sources, for readers who want them.
Failure risks
| Failure | Trigger and consequence |
|---|---|
| Overheating of the bearing lininghigh severity | Operating temperature rises to the solidus of 241 degCThe Kapp datasheet gives a solidus of 241 degC and a liquidus of 354 degC. Above the solidus the alloy starts to melt, so the lining loses its strength before it reaches the liquidus. No failure test was read for this grade. |
| Tin pest, transformation to grey tinmoderate severity | Exposure to temperatures at or below 13.2 degCWikipedia gives a volume increase of about 27% for the change to grey tin. The source gives no rate for the babbitt alloy, and the alloy is not tested for this change. |
Handling and storage
- The PubChem hazard codes above (H319, H335 and H372 for tin; H301, H302, H332 and H351 for antimony; H360 and H372 for lead) are for the elements, not for a babbitt grade. The sources read give no handling advice for the alloy; check the supplier's safety data sheet for the grade you buy.
Supply and geography
How common the raw materials are and where they come from.
Tin (mine production)
- Top producers (2025)
- China 24.5%, Indonesia 21%, Peru 11.4%, Brazil 9.7%, Congo (Kinshasa) 9.3%
- Recycling
- USGS: about 17,000 tons of tin from old and new scrap was recycled in 2025, accounting for 22% of apparent consumption.
- Substitutes
- USGS: plastics for bearing metals that contain tin; epoxy resins for solder; alternative copper-base alloys for bronze.
Antimony (mine production)
- Top producers (2025)
- China 36.4%, Russia 29.1%, Tajikistan 20%, Bolivia 4.5%, Australia 1.2%
- Recycling
- USGS: recycling supplied 12% of estimated domestic apparent consumption in 2025.
- Substitutes
- USGS: combinations of calcium, copper, selenium, sulfur, and tin are substitutes for alloys in lead-acid batteries.
Documents
Datasheets, safety data sheets, papers and standards you can open.
Full record
The complete spore, as stored. Free to reuse under CC-BY-4.0. Images keep the licence shown with each one.
Show the full YAML
spore: profile
id: tin-antimony-babbitt
spore_version: 0.2
family: low-melting-metals-and-solders
name: Tin-antimony babbitt (tin-base bearing metal)
abbreviation: Sn-Sb-Cu
role: soft bearing-lining alloy
category: metals
type: heavy-metals
summary: |
Tin-base babbitt is a soft alloy of tin with about 7.5% antimony and 3.5% copper (ASTM B23 Grade 2, nominal 89% tin). It is used as a thin running surface in plain bearings. The ASTM B23 Grade 2 grade has a density of 7.39 g/cm3, a solidus of 241 degC and a liquidus of 354 degC, a Brinell hardness of 24.5, and a chill-cast tensile strength of 77.0 MPa, according to the Kapp Alloy datasheet. Its elongation differs between two datasheets (18% on Kapp, 8.0% on Trotter), and the sheets give no test conditions for the Trotter figure.
best_for: 'Thin plain-bearing linings that must tolerate repeated loading: Wikipedia says combustion engines use tin-based babbitt because it withstands cyclic loading'
weakest_at: 'Strength and temperature: a solidus of 241 degC, a Brinell hardness of 24.5 and 42.1 MPa compressive yield. Tin pest and antimony toxicity add cold and handling limits.'
identity:
formula: 'Tin-base babbitt ASTM B23 Grade 2: Sn 89, Sb 7.5, Cu 3.5 nominal (mass %), limits Sn 88 to 90, Sb 7 to 8, Cu 3 to 4, Pb up to 0.35. Lead-based babbitt BS 3332 Alloy G: Pb balance, Sn 4.5 to 6.5, Sb 14 to 17 (mass %). Pewter: tin 85 to 99, antimony about 5 to 10, copper about 2 (mass %); typical European casting pewter Sn 94, Cu 1, Sb 5.'
source: kapp-grade2
where: Chemical composition limits on the Kapp Alloy product page and the Nathan Trotter datasheet (Sn 89 / Sb 7.5 / Cu 3.5, Pb below 0.35); Wikipedia Babbitt metal (BS 3332 Alloy G) and Wikipedia Pewter (composition paragraphs)
designations:
- system: ASTM
code: B23
note: Grade 2 tin-base babbitt (the Trotter sheet lists it as ASTM B23-00 Alloy 2)
source: kapp-grade2
where: 'Page title ASTM-B23 Grade 2 Tin Babbitt and specification section ASTM B23: Grade 2'
tags:
applications:
- mechanisms
- electronics-and-chips
- batteries
properties:
- benchmark: density
label: Density of tin-base babbitt, ASTM B23 Grade 2
value: 7.39
unit: g/cm3
scope: material
conditions:
composition: ASTM B23 Grade 2, nominal Sn 89 / Sb 7.5 / Cu 3.5 (mass %)
temperature: not stated
method: Value printed on the Kapp Alloy product page. The same page also prints the unit as mg/m3 once, which is a misprint.
status: ground
source: kapp-grade2
where: Physical properties, density row (7.39 g/cc, 0.267 lb/in3)
- benchmark: melting_point
label: Solidus to liquidus range, tin-base babbitt
value: 241
value_high: 354
bound: range
unit: degC
scope: material
conditions:
basis: printed as 466-669 degF (241-354 degC)
composition: ASTM B23 Grade 2
method: Range printed on the Kapp Alloy product page; the Trotter datasheet prints the same 466 and 669 degF as solidus and liquidus.
status: ground
source: kapp-grade2
where: Physical properties, melting range line (466-669 degF (241-354 degC))
- benchmark: brinell_hardness
label: Brinell hardness, tin-base babbitt
value: 24.5
unit: HB
scope: material
conditions:
ball: 10 mm
load: 500 kg
time: 30 s
composition: ASTM B23 Grade 2
method: Value printed on the Kapp Alloy product page with its test conditions
status: ground
note: The name brinell_hardness is not in spores/property-canon.yaml and is used as it is.
source: kapp-grade2
where: Hardness row (24.5, 10 mm ball / 500 kg load - 30 sec)
- benchmark: ultimate_tensile_strength
label: Ultimate tensile strength, chill cast at 20 degC
value: 77
unit: MPa
scope: material
conditions:
casting: chill cast
temperature: 20 degC (68 degF)
composition: ASTM B23 Grade 2
method: Value in the chill-cast table of the Kapp Alloy product page
status: ground
source: kapp-grade2
where: Tensile table, chill cast row at 20 degC (77.0 MPa, 11,200 psi)
- benchmark: ultimate_tensile_strength
label: Ultimate tensile strength, die cast
value: 87
unit: MPa
scope: material
conditions:
casting: die cast, poured at 600 degF (315 degC) into a 302 degF (150 degC) mold
composition: ASTM B23 Grade 2
method: Value printed on the Kapp Alloy product page, footnote and die-cast entry
status: ground
source: kapp-grade2
where: Tensile entry labelled Diecast (87.0 MPa, 12,600 psi)
- benchmark: elongation
label: Elongation at break, chill cast (Kapp)
value: 18
unit: '%'
scope: material
conditions:
casting: chill cast
temperature: 20 degC
gage: 4 x (area)^1/2 gage length
method: Value printed on the Kapp Alloy product page, chill-cast entry
status: ground
source: kapp-grade2
where: Elongation entry, chill cast (18% at break)
- benchmark: elongation
label: Elongation, ASTM B23 Grade 2 datasheet (Trotter)
value: 8
unit: '%'
scope: material
conditions:
basis: product data sheet, no test condition printed
composition: ASTM B23 Grade 2
method: Value printed on the Nathan Trotter Grade 2 datasheet. It is lower than the chill-cast figure from Kapp, and the two sheets do not give matching test conditions.
status: ground
source: trotter-grade2
where: Physical properties, Elongation % row (8.0)
- benchmark: elastic_modulus
label: Tensile elastic modulus, cast tin-base babbitt
value: 52
unit: GPa
scope: material
conditions:
test: tension
casting: cast at 400 degC into a 100 degC mold
method: Value in the mechanical properties table of the Kapp Alloy product page
status: ground
source: kapp-grade2
where: Elastic modulus row (52 GPa)
- benchmark: fatigue_strength
label: Fatigue strength, chill cast tin-base babbitt
value: 33
unit: MPa
scope: material
conditions:
test: R.R. Moore
cycles: 2 x 10^7 (printed as 2 x 107)
casting: chill cast
method: Value printed on the Kapp Alloy product page, fatigue entry
status: ground
source: kapp-grade2
where: Fatigue entry, R.R. Moore test (33.0 MPa, 4790 psi)
- benchmark: compressive_yield_strength
label: Compressive yield strength, tin-base babbitt
value: 42.1
unit: MPa
scope: material
conditions:
set: 0.125% set
composition: ASTM B23 Grade 2
method: Value printed on the Kapp Alloy product page, compressive entry
status: ground
note: The name compressive_yield_strength is not in spores/property-canon.yaml and is used as it is.
source: kapp-grade2
where: Compressive entry (42.1 MPa at 0.125% set)
- benchmark: melting_point
label: Melting point of pure tin, for comparison with the babbitt
value: 231.9
unit: degC
scope: material
conditions:
form: pure tin
pressure: not stated
method: Value listed in the melting point section of the PubChem record for tin
status: ground
source: pubchem-tin
where: Experimental Properties, melting point entries (231.9 degC)
- benchmark: allotropic_transformation_temperature
label: Tin pest transition, white tin to grey tin
value: 13.2
unit: degC
scope: material
conditions:
transformation: white (beta) tin to grey (alpha) tin, at and below the temperature
basis: pure tin; the babbitt alloy is not tested
method: Value printed in the allotropic transformation section of Wikipedia Tin pest
status: ground
note: The name allotropic_transformation_temperature is not in spores/property-canon.yaml and is used as it is.
source: wiki-tin-pest
where: Allotropic transformation section, At 13.2 degC (55.8 degF) and below
- benchmark: volume_change
label: Volume increase, white tin to grey tin
value: 27
unit: '%'
scope: material
conditions:
basis: change from white (beta) to grey (alpha) tin
composition: pure tin
method: Value printed in the allotropic transformation section of Wikipedia Tin pest
status: ground
source: wiki-tin-pest
where: Allotropic transformation section, a large volume increase of about 27%
- benchmark: melting_point
label: Melting point of antimony metal, the alloying element
value: 630
unit: degC
scope: material
conditions:
form: antimony metal
pressure: not stated
method: Value listed in the melting point section of the PubChem record for antimony
status: ground
source: pubchem-antimony
where: Experimental Properties, melting point entries (630 degC)
- benchmark: density
label: Density of antimony metal, the alloying element
value: 6.68
unit: g/cm3
scope: material
conditions:
temperature: 20 degC
form: antimony metal
method: Value printed in the density section of the PubChem record for antimony
status: ground
source: pubchem-antimony
where: Experimental Properties, density entries (6.68 g/cu cm at 20 degC)
corrosion:
- environment: Below 13.2 degC, pure tin
headline: At and below 13.2 degC, white tin can change to grey tin with a volume increase of about 27%.
effect: Wikipedia gives 13.2 degC as the temperature at and below which the change happens. It says the change is slow to start because of a high activation energy and then speeds up, and it gives a volume increase of about 27%. No rate test on the babbitt alloy was found.
rating: moderate
conditions:
basis: pure tin; alloy behaviour not stated in the source
condition: temperature at or below 13.2 degC
source: wiki-tin-pest
where: Allotropic transformation section
risks:
hazards:
- text: 'PubChem notifications for antimony metal (CID 5354495): H301 (18.2%) toxic if swallowed, H302 (23.4%) harmful if swallowed, H332 (26.9%) harmful if inhaled, H351 (31.8%) suspected of causing cancer. Signal word Danger. 18.7% (140 of 748) of company reports say antimony does not meet GHS criteria.'
ghs:
- H301
- H302
- H332
- H351
source: pubchem-antimony
where: GHS Classification section, aggregated ECHA notifications (CID 5354495)
- text: 'PubChem notifications for lead (CID 5352425): H360 (84.4%) may damage fertility or the unborn child, H372 (50.5%) causes damage to organs through prolonged or repeated exposure. Signal word Danger.'
ghs:
- H360
- H372
source: pubchem-lead
where: GHS Classification section, aggregated ECHA notifications (CID 5352425)
- text: 'PubChem notifications for tin (CID 5352426): 72.9% (695 of 953) of company reports say tin does not meet GHS criteria. Where codes were given, H319 (24.2%) causes serious eye irritation and H335 (23.1%) may cause respiratory irritation. Signal word Warning. One further notification gives H372, damage to organs through prolonged or repeated exposure.'
ghs:
- H319
- H335
- H372
source: pubchem-tin
where: GHS Classification section, ECHA and NITE-CMC notifications (CID 5352426)
failure_risks:
- mode: Overheating of the bearing lining
trigger: Operating temperature rises to the solidus of 241 degC
consequence: The Kapp datasheet gives a solidus of 241 degC and a liquidus of 354 degC. Above the solidus the alloy starts to melt, so the lining loses its strength before it reaches the liquidus. No failure test was read for this grade.
severity: high
source: kapp-grade2
where: Physical properties, melting range line
- mode: Tin pest, transformation to grey tin
trigger: Exposure to temperatures at or below 13.2 degC
consequence: Wikipedia gives a volume increase of about 27% for the change to grey tin. The source gives no rate for the babbitt alloy, and the alloy is not tested for this change.
severity: moderate
source: wiki-tin-pest
where: Allotropic transformation section
side_effects: []
handling:
- text: The PubChem hazard codes above (H319, H335 and H372 for tin; H301, H302, H332 and H351 for antimony; H360 and H372 for lead) are for the elements, not for a babbitt grade. The sources read give no handling advice for the alloy; check the supplier's safety data sheet for the grade you buy.
source: pubchem-antimony
where: GHS Classification sections, CID 5354495, 5352425 and 5352426
mitigations: []
uses:
- application: mechanisms
device: Engine plain bearings (tin-based babbitt)
example: 'Wikipedia: internal combustion engines use Babbitt metal which is primarily tin-based because it can withstand cyclic loading. Poured Babbitt bearings were common in automotive applications until the mid-1950s.'
source: wiki-babbitt
where: Lead introduction and Design, Modern section
- application: mechanisms
device: Bearing metals, bronze and brass (babbitt, tinning)
example: 'USGS: babbitt, brass and bronze, and tinning together took 7% of tin use in the United States in 2025.'
source: usgs-mcs2026-tin
where: Domestic Production and Use paragraph (uses percentages)
- application: electronics-and-chips
device: Solder
example: 'USGS: solder took 11% of tin use in the United States in 2025.'
source: usgs-mcs2026-tin
where: Domestic Production and Use paragraph (uses percentages)
- application: batteries
device: Antimonial lead for lead-acid battery plates (antimony context)
example: 'USGS: secondary antimony was intended for the lead-acid battery industry, and antimonial lead and ammunition took 40% of antimony use in the United States in 2025.'
source: usgs-mcs2026-antimony
where: Domestic Production and Use paragraph
supply:
- subject: Tin (mine production)
producers:
- country: China
share_percent: 24.5
year: 2025
- country: Indonesia
share_percent: 21
year: 2025
- country: Peru
share_percent: 11.4
year: 2025
- country: Brazil
share_percent: 9.7
year: 2025
- country: Congo (Kinshasa)
share_percent: 9.3
year: 2025
recycling: 'USGS: about 17,000 tons of tin from old and new scrap was recycled in 2025, accounting for 22% of apparent consumption.'
substitutes:
- 'USGS: plastics for bearing metals that contain tin; epoxy resins for solder; alternative copper-base alloys for bronze.'
source: usgs-mcs2026-tin
where: World Mine Production and Reserves table, 2025e column (world total 290,000 t; shares calculated by Space Mushroom from China 71,000, Indonesia 61,000, Peru 33,000, Brazil 28,000 and Congo (Kinshasa) 27,000 over the world total); Recycling; Substitutes
- subject: Antimony (mine production)
producers:
- country: China
share_percent: 36.4
year: 2025
- country: Russia
share_percent: 29.1
year: 2025
- country: Tajikistan
share_percent: 20
year: 2025
- country: Bolivia
share_percent: 4.5
year: 2025
- country: Australia
share_percent: 1.2
year: 2025
recycling: 'USGS: recycling supplied 12% of estimated domestic apparent consumption in 2025.'
substitutes:
- 'USGS: combinations of calcium, copper, selenium, sulfur, and tin are substitutes for alloys in lead-acid batteries.'
source: usgs-mcs2026-antimony
where: World Mine Production and Reserves table, 2025e column (world total 110,000 t; shares calculated by Space Mushroom from China 40,000, Russia 32,000, Tajikistan 22,000, Bolivia 5,000 and Australia 1,300 over the world total); Recycling; Substitutes
media: []
documents:
- title: 'Nathan Trotter & Co. product data sheet: ASTM Grade 2 Babbitt Metal (Rev. 3, 2015)'
type: datasheet
url: https://nathantrotter.com/wp-content/uploads/2020/09/Grade-2-Babbitt-Data.pdf
year: 2015
- title: 'Kapp Alloy: DuraKapp 2, ASTM B23 Grade 2 Tin Babbitt'
type: datasheet
url: https://www.kappalloy.com/babbitt-alloy/tin-babbitt-alloys/durakapp-2/
- title: 'USGS Mineral Commodity Summaries 2026: Antimony'
type: report
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-antimony.pdf
year: 2026
- title: 'USGS Mineral Commodity Summaries 2026: Tin'
type: report
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-tin.pdf
year: 2026
- title: 'PubChem compound record: Antimony (CID 5354495), GHS classification and experimental properties'
type: database
url: https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/5354495/JSON
year: 2026
- title: 'PubChem compound record: Lead (CID 5352425), GHS classification'
type: database
url: https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/5352425/JSON
year: 2026
- title: 'PubChem compound record: Tin (CID 5352426), experimental properties and GHS classification'
type: database
url: https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/5352426/JSON
year: 2026
gaps:
- No standard text (ASTM B23 or BS 3332) was opened; the composition and property values come from vendor and distributor datasheets, not from the standards themselves.
- Elongation disagrees between the two datasheets (18% chill cast on Kapp, 8.0% on Trotter) and neither gives a full test set; both are recorded.
- The Kapp page prints the lead limit as 0.1000% in one list and 0.35% in the component table; the Trotter sheet prints below 0.35%. Only the 0.35% limit is used.
- Lead-based babbitt (BS 3332 Alloy G) is recorded for composition only. No property, corrosion or hazard value for a Sn-Pb-Sb babbitt was read in this run.
- 'Bismuth-tin alloys were not covered: no source for them was read in this run, so no value is given.'
- Pewter composition is recorded from Wikipedia (general ranges). The Britannia metal composition was not printed on the page read, and no pewter property value was read.
- No corrosion test, ageing data or service-environment result was found for tin-antimony babbitt (oil, humidity, fuel or seawater).
- Tin whisker growth on tin-rich alloys was not read in this run (see the tin profile for the NASA source).
- No space-environment data (outgassing, vacuum, radiation, atomic oxygen, thermal cycling) was found for any tin-antimony alloy. No flight use of babbitt was found.
- Antimony critical-mineral status is not stated in the USGS MCS 2026 antimony text read here, and the USGS 2025 critical list was not opened, so critical_lists is left out.
- Brinell hardness on the Trotter sheet is printed as 24.5/12 with no test conditions, so only the Kapp row (10 mm ball, 500 kg, 30 s) is used.
- The Sn-Sb binary phase diagram and a thermal conductivity value for the babbitt grade were not found in a fetched source.
- UNS, EN and JIS designations for tin-base babbitt were not printed on any fetched page, so only the ASTM B23 Grade 2 designation is listed.
sources:
kapp-grade2:
title: 'Kapp Alloy: DuraKapp 2, ASTM B23 Grade 2 Tin Babbitt (product page with physical and mechanical data)'
url: https://www.kappalloy.com/babbitt-alloy/tin-babbitt-alloys/durakapp-2/
kind: datasheet
license: vendor product page, cited not reproduced
trotter-grade2:
title: Nathan Trotter & Co. product data sheet, ASTM Grade 2 Babbitt Metal (SPEC NO NT Grade 2 Babbitt, Rev. 3, 2015)
id: ASTM B23-00 Alloy 2 on the sheet
url: https://nathantrotter.com/wp-content/uploads/2020/09/Grade-2-Babbitt-Data.pdf
year: 2015
kind: datasheet
license: supplier document, cited not reproduced
wiki-babbitt:
title: Babbitt metal, Wikipedia (history, BS 3332 alloy compositions, bearing uses)
url: https://en.wikipedia.org/wiki/Babbitt_metal
kind: web
license: CC BY-SA 4.0, linked not reproduced
wiki-pewter:
title: Pewter, Wikipedia (composition ranges and types)
url: https://en.wikipedia.org/wiki/Pewter
kind: web
license: CC BY-SA 4.0, linked not reproduced
wiki-tin-pest:
title: Tin pest, Wikipedia (allotropic transformation at 13.2 degC, volume increase)
url: https://en.wikipedia.org/wiki/Tin_pest
kind: web
license: CC BY-SA 4.0, linked not reproduced
usgs-mcs2026-tin:
title: 'Mineral Commodity Summaries 2026: Tin (U.S. Geological Survey)'
id: USGS MCS 2026, February 2026
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-tin.pdf
year: 2026
kind: report
license: public domain (USGS)
usgs-mcs2026-antimony:
title: 'Mineral Commodity Summaries 2026: Antimony (U.S. Geological Survey)'
id: USGS MCS 2026, February 2026
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-antimony.pdf
year: 2026
kind: report
license: public domain (USGS)
pubchem-antimony:
title: 'PubChem compound record: Antimony (CID 5354495), experimental properties and GHS classification'
id: CID 5354495
url: https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/5354495/JSON
year: 2026
kind: database
license: PubChem (NCBI), public domain; sections attributed to ECHA and other databases
pubchem-lead:
title: 'PubChem compound record: Lead (CID 5352425), GHS classification'
id: CID 5352425
url: https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/5352425/JSON
year: 2026
kind: database
license: PubChem (NCBI), public domain; sections attributed to ECHA and other databases
pubchem-tin:
title: 'PubChem compound record: Tin (CID 5352426), experimental properties and GHS classification'
id: CID 5352426
url: https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/5352426/JSON
year: 2026
kind: database
license: PubChem (NCBI), public domain; sections attributed to ECHA, NITE-CMC and other databases
license: CC-BY-4.0
updated: '2026-10-26'
review:
status: draft
method: assistant
checked_values: 15
unreachable: 0
caveats: 5
note: 'Values were read by an AI assistant on 2026-10-26 from the datasheets, USGS PDFs, PubChem JSON records and Wikipedia pages named in each entry. Caveats: the babbitt values come from vendor datasheets, not the ASTM standard; the two elongation figures disagree; the PubChem antimony GHS notifications do not give test conditions; the USGS antimony shares are calculated; pewter and Sn-Pb-Sb values are composition only.'
story:
recipe:
line: Tin-base babbitt (ASTM B23 Grade 2) is a tin alloy with about 7.5% antimony and 3.5% copper. The nominal composition is 89% tin, 7.5% antimony and 3.5% copper, within limits of 88 to 90% tin, 7 to 8% antimony and 3 to 4% copper, with lead at or below 0.35%.
parts:
- name: Tin
symbol: Sn
share_percent: 89
role: The base metal, 88 to 90% of the alloy by the datasheet limits.
- name: Antimony
symbol: Sb
share_percent: 7.5
role: The main alloying addition, limit 7 to 8%.
- name: Copper
symbol: Cu
share_percent: 3.5
role: A second alloying addition, limit 3 to 4%.
risk_groups:
- title: For people
level: 0
verdict: Hazard codes apply to the elements
lead: The babbitt is mostly tin, but the PubChem notifications for antimony and lead carry serious hazard codes.
points:
- label: Antimony
line: PubChem notifications for antimony metal give H301 at 18.2%, H332 at 26.9% and H351 (suspected of causing cancer) at 31.8%, with signal word Danger.
- label: Lead
line: PubChem notifications for lead give H360 at 84.4%, which covers harm to fertility or the unborn child, and H372 at 50.5%.
- label: Tin
line: PubChem notifications for tin give H319 at 24.2% and H335 at 23.1%. A further notification gives H372.
- title: If the lining overheats
level: 1
verdict: Melts from 241 to 354 degC
lead: The melting range of the babbitt and the cold change of tin are the two temperature limits the sources give.
points:
- label: Melting range
line: The Kapp datasheet gives a solidus of 241 degC and a liquidus of 354 degC. The alloy starts to melt at the solidus, so its strength falls before the liquidus.
- label: Tin pest
line: Wikipedia gives 13.2 degC as the temperature at and below which white tin changes to grey tin, with a volume increase of about 27%.
- title: Handling and storage
level: 2
verdict: No handling advice for the alloy
lead: The sources read give no handling advice for the babbitt grade itself.
points:
- label: Safety data
line: Check the supplier's safety data sheet for the grade you buy. The PubChem codes above belong to the elements.
why: Tin-base babbitt is a soft tin alloy with about 7.5% antimony and 3.5% copper. It is used as a thin running surface in plain bearings. The ASTM B23 Grade 2 grade has a density of 7.39 g/cm3, a solidus of 241 degC and a liquidus of 354 degC, and a Brinell hardness of 24.5 with a 10 mm ball and a 500 kg load. Its tensile strength is 77 MPa when chill cast. Wikipedia describes babbitt as a thin surface layer in a multi-metal bearing and says combustion engines use tin-based babbitt because it tolerates cyclic loading. Pure tin melts at 231.9 degC, so the babbitt starts to melt at a higher temperature than the pure metal.
uses:
- where: Engine bearings
line: Internal combustion engines use babbitt that is primarily tin-based because it can withstand cyclic loading (Wikipedia). Poured babbitt bearings were common in cars until the mid-1950s.
- where: Bearing metals, solder and tinning
line: Babbitt, brass and bronze, and tinning together took 7% of U.S. tin use in 2025, and solder took 11% (USGS).
- where: Lead-acid batteries (antimony)
line: Antimonial lead and ammunition took 40% of U.S. antimony use in 2025, and secondary antimony was intended for the lead-acid battery industry (USGS).
can_do:
- label: Melt range
value: 241 to 354 degC
benchmark: melting_point
line: The tin-base babbitt starts to melt at 241 degC and is fully liquid at 354 degC (Kapp). Pure tin melts at 231.9 degC.
- label: Hardness
value: 24.5 HB
benchmark: brinell_hardness
line: Brinell hardness is 24.5 at a 500 kg load with a 10 mm ball (Kapp). Chill cast, the tensile strength is 77 MPa.
- label: Stiffness
value: 52 GPa
benchmark: elastic_modulus
line: The tensile elastic modulus is 52 GPa for the alloy cast at 400 degC into a 100 degC mold (Kapp).
- label: Fatigue
value: 33 MPa
benchmark: fatigue_strength
line: Kapp gives a fatigue strength of 33 MPa at 2 x 10^7 cycles in an R.R. Moore test.
compare: The babbitt starts to melt at 241 degC, above pure tin at 231.9 degC, and well below antimony metal at 630 degC. It is denser than antimony (7.39 against 6.68 g/cm3). The rows below compare the babbitt with those reference values.
compare_rows:
- label: Density
benchmark: density
- label: Melting point
benchmark: melting_point
- label: Hardness
benchmark: brinell_hardness
handling:
- Check the supplier's safety data sheet for the babbitt grade you buy; the sources read give no handling advice for the alloy.
- Treat dust and fume from melting or machining as the PubChem codes show for tin, antimony and lead.
- Keep the lining below its 241 degC solidus in service, and keep tin-rich parts above 13.2 degC if the change to grey tin matters.
good_for:
- 'Thin plain-bearing linings: the Kapp datasheet gives a Brinell hardness of 24.5 and a tensile strength of 77 MPa when chill cast.'
- 'Engine bearings: Wikipedia says tin-based babbitt is used in combustion engines because it withstands cyclic loading.'
watch_out:
- 'Melting range: the babbitt begins to melt at 241 degC, well below the 630 degC melting point of antimony metal.'
- Elongation differs by source (18% on Kapp, 8.0% on Trotter) and the Trotter figure has no test conditions.
- 'Tin pest: below 13.2 degC, white tin can change to grey tin with a volume increase of about 27%; no test on the alloy was found.'
- Antimony and lead carry serious PubChem hazard codes; the babbitt itself has no hazard data in the sources read.
verdict: Tin-base babbitt is a soft, low-melting bearing alloy with a solidus of 241 degC, a Brinell hardness of 24.5 and a 77 MPa chill-cast tensile strength. Its uses are in engine bearings and as a bearing metal. Its weak points are the low melting range, the cold change of tin, and the absence of test data on corrosion, ageing and space environments. Elongation values disagree between datasheets.
References
Every number above carries a reference number. Click one to see the source and where in it the value comes from.