PH 13-8Mo stainless steel PH 13-8Mo

spore: profile
id: stainless-13-8mo
spore_version: 0.2
family: stainless-steels
name: PH 13-8Mo stainless steel
abbreviation: PH 13-8Mo
role: high-toughness precipitation-hardening stainless steel for aerospace fasteners, shafts and hardware
category: metals
type: steels-and-stainless
summary: |
  PH 13-8 Mo (UNS S13800, EN 1.4534, AMS 5629) is a precipitation-hardening stainless steel. Its typical yield strength is 1449 MPa in condition H 950 (longitudinal, per the HiTemp Metals datasheet), and the Bibus datasheet gives a minimum of 1413 MPa for the same condition. Its marine stress-corrosion resistance is described as high, and its Charpy V-notch energy is 41 J in condition H 1000 and 27 J in condition H 950.
best_for: 'Strong stainless parts for marine or humid air: a typical yield strength of 1449 MPa in condition H 950 and a high level of stress-corrosion resistance in marine tests'
weakest_at: Strength falls as the ageing temperature rises, and toughness rises with it; no space-environment data (outgassing, atomic oxygen or radiation) for this alloy were found in any source read
identity:
  formula: 'Iron-based precipitation-hardening stainless steel: iron with chromium, nickel, molybdenum and aluminium as the main alloying elements (limits in the recipe parts)'
  designations:
    - system: UNS
      code: S13800
      source: bibus
      where: Header line printed as 1.4534.9 | UNS S13800 | AMS 5629
    - system: AMS
      code: '5629'
      source: bibus
      where: Header line printed as 1.4534.9 | UNS S13800 | AMS 5629
    - system: EN
      code: '1.4534'
      source: bibus
      where: Header line printed as 1.4534.9, and page title PH 13-8 Mo | 1.4534
    - system: Trade name
      code: PH 13-8 Mo
      source: hightempmetals
      where: 'Page title and trademark note: PH 13-8 Mo stainless is a registered trademark of Armco Inc.'
  source: bibus
  where: 'Chemical composition limits in % from the Bibus table, with decimal commas written as points: Fe rest; Cr 12.25 to 13.25; Ni 7.50 to 8.50; Mo 2.00 to 2.50; Al 0.90 to 1.35; Mn max 0.20; N max 0.10; Si max 0.10; C max 0.05; P max 0.01. The HiTemp Metals type analysis differs for two elements: Mn max 0.10 and N max 0.01. Both are recorded here and the two sources disagree.'
tags:
  environments: []
  stresses: []
  applications:
    - structures
    - mechanisms
properties:
  - benchmark: density
    label: Density, PH 13-8 Mo (Bibus datasheet)
    value: 7.76
    unit: g/cm3
    scope: material
    conditions:
      condition: not stated on the page
      unit_in_source: g/cm³
    method: Value printed in a supplier datasheet
    status: ground
    source: bibus
    where: Physical constants and thermal properties table, row Density
  - benchmark: melting_point
    label: Melting point, PH 13-8 Mo (Bibus datasheet)
    value: 1404
    unit: °C
    scope: material
    conditions:
      note: single value printed, no range
    method: Single value printed in a supplier datasheet
    status: ground
    source: bibus
    where: Physical constants and thermal properties table, row Melting point
  - benchmark: thermal_conductivity
    label: Thermal conductivity at 20 °C, PH 13-8 Mo (Bibus datasheet)
    value: 12.8
    unit: W/m - °C
    scope: material
    conditions:
      temperature: 20 °C
      unit_in_source: W/m - °C
    method: Value printed in a supplier datasheet
    status: ground
    source: bibus
    where: Physical constants and thermal properties table, row Thermal conductivity at 20°C
  - benchmark: thermal_conductivity
    label: Thermal conductivity at 100 °C, condition A (HiTemp Metals datasheet)
    value: 14
    unit: W/m-K
    scope: material
    conditions:
      temperature: 100 °C (212 °F)
      condition_printed: Condition A
      unit_in_source: W/m-K
    method: Value printed in a supplier datasheet
    status: ground
    source: hightempmetals
    where: Thermal Conductivity section, Condition A at 212°F / 100°C, printed as 97.2 Btu-in/ft²-h-°F (14.0 W/m-K)
  - benchmark: cte
    label: Mean coefficient of thermal expansion, 20 to 100 °C (Bibus datasheet)
    value: 13
    unit: μm/m - °C
    scope: material
    conditions:
      temperature: 20 to 100 °C
      unit_in_source: μm/m - °C
    method: Value printed in a supplier datasheet; it differs from the HiTemp Metals value at a different temperature range (see gaps)
    status: ground
    source: bibus
    where: Physical constants and thermal properties table, row Coefficient of expansion at 20-100°C
  - benchmark: cte
    label: Mean coefficient of thermal expansion, condition H 1000, 21 to 204 °C (HiTemp Metals datasheet)
    value: 10.8
    unit: 10⁻⁶/K
    scope: material
    conditions:
      condition: H 1000
      temperature: 21 to 204 °C (70 to 400 °F)
      unit_in_source: 10⁻⁶/K
    method: Value printed in a supplier datasheet
    status: ground
    source: hightempmetals
    where: Mean Coefficient of Thermal Expansion table, row 70-400°F (21-204°C), column H 1000, second value of 6.0 / 10.8
  - benchmark: electrical_resistivity
    label: Electrical resistivity, condition A (HiTemp Metals datasheet)
    value: 1020
    unit: microhm-mm
    scope: material
    conditions:
      temperature: 100 °C (212 °F)
      condition_printed: Condition A
      unit_in_source: microhm-mm
    method: Value printed in a supplier datasheet; the same page also prints 613 ohms c/mf (not recorded here)
    status: ground
    source: hightempmetals
    where: Electrical Resistivity section, Condition A at 212°F / 100°C, second line
  - benchmark: yield_strength
    label: Yield strength 0.2 % offset, H 950, typical longitudinal (HiTemp Metals datasheet)
    value: 1449
    unit: MPa
    scope: material
    conditions:
      condition: H 950
      form: typical longitudinal, center or intermediate location
      temperature: room temperature
      basis: typical
    method: Typical value printed in a supplier datasheet; this is a typical value, not a minimum
    status: ground
    source: hightempmetals
    where: Typical Longitudinal Room-Temperature Mechanical Properties table, row H 950, column 0.2% Yield (ksi / MPa), printed as 210 / 1449
  - benchmark: yield_strength
    label: Yield strength, H 950, minimum (Bibus datasheet)
    value: 1413
    unit: MPa
    scope: material
    conditions:
      condition: H950
      basis: minimum, room temperature
    method: Minimum value printed under the heading Typical mechanical properties (room temperature)
    status: ground
    source: bibus
    where: Typical mechanical properties table, row H950, column Yield strength, printed as min. 1413 MPa
  - benchmark: yield_strength
    label: Yield strength 0.2 % offset, H 1000, typical longitudinal (HiTemp Metals datasheet)
    value: 1413
    unit: MPa
    scope: material
    conditions:
      condition: H 1000
      form: typical longitudinal, center or intermediate location
      temperature: room temperature
      basis: typical
    method: Typical value printed in a supplier datasheet
    status: ground
    source: hightempmetals
    where: Typical Longitudinal Room-Temperature Mechanical Properties table, row H 1000, column 0.2% Yield (ksi / MPa), printed as 205 / 1413
  - benchmark: yield_strength
    label: Yield strength, H 1000, minimum (Bibus datasheet)
    value: 1310
    unit: MPa
    scope: material
    conditions:
      condition: H1000
      basis: minimum, room temperature
    method: Minimum value printed under the heading Typical mechanical properties (room temperature)
    status: ground
    source: bibus
    where: Typical mechanical properties table, row H1000, column Yield strength, printed as min. 1310 MPa
  - benchmark: yield_strength
    label: Yield strength, H 1050, minimum (Bibus datasheet)
    value: 1138
    unit: MPa
    scope: material
    conditions:
      condition: H1050
      basis: minimum, room temperature
    method: Minimum value printed under the heading Typical mechanical properties (room temperature)
    status: ground
    source: bibus
    where: Typical mechanical properties table, row H1050, column Yield strength, printed as min. 1138 MPa
  - benchmark: ultimate_tensile_strength
    label: Tensile strength, H 950, typical longitudinal (HiTemp Metals datasheet)
    value: 1551
    unit: MPa
    scope: material
    conditions:
      condition: H 950
      form: typical longitudinal, center or intermediate location
      temperature: room temperature
      basis: typical
    method: Typical value printed in a supplier datasheet
    status: ground
    source: hightempmetals
    where: Typical Longitudinal Room-Temperature Mechanical Properties table, row H 950, column UTS (ksi / MPa), printed as 225 / 1551
  - benchmark: ultimate_tensile_strength
    label: Tensile strength, H 950, minimum (Bibus datasheet)
    value: 1517
    unit: MPa
    scope: material
    conditions:
      condition: H950
      basis: minimum, room temperature
    method: Minimum value printed under the heading Typical mechanical properties (room temperature)
    status: ground
    source: bibus
    where: Typical mechanical properties table, row H950, column Tensile strength, printed as min. 1517 MPa
  - benchmark: ultimate_tensile_strength
    label: Tensile strength, H 1000, typical longitudinal (HiTemp Metals datasheet)
    value: 1482
    unit: MPa
    scope: material
    conditions:
      condition: H 1000
      form: typical longitudinal, center or intermediate location
      temperature: room temperature
      basis: typical
    method: Typical value printed in a supplier datasheet
    status: ground
    source: hightempmetals
    where: Typical Longitudinal Room-Temperature Mechanical Properties table, row H 1000, column UTS (ksi / MPa), printed as 215 / 1482
  - benchmark: ultimate_tensile_strength
    label: Tensile strength, H 1000, minimum (Bibus datasheet)
    value: 1413
    unit: MPa
    scope: material
    conditions:
      condition: H1000
      basis: minimum, room temperature
    method: Minimum value printed under the heading Typical mechanical properties (room temperature)
    status: ground
    source: bibus
    where: Typical mechanical properties table, row H1000, column Tensile strength, printed as min. 1413 MPa
  - benchmark: ultimate_tensile_strength
    label: Tensile strength, H 1050, minimum (Bibus datasheet)
    value: 1207
    unit: MPa
    scope: material
    conditions:
      condition: H1050
      basis: minimum, room temperature
    method: Minimum value printed under the heading Typical mechanical properties (room temperature)
    status: ground
    source: bibus
    where: Typical mechanical properties table, row H1050, column Tensile strength, printed as min. 1207 MPa
  - benchmark: elongation
    label: Elongation in 2 in., H 1000, typical longitudinal (HiTemp Metals datasheet)
    value: 13
    unit: '%'
    scope: material
    conditions:
      condition: H 1000
      gauge_length: 2 in.
      form: typical longitudinal
      basis: typical
    method: Typical value printed in a supplier datasheet
    status: ground
    source: hightempmetals
    where: Typical Longitudinal Room-Temperature Mechanical Properties table, row H 1000, column Elong. in 2" (%)
  - benchmark: elongation
    label: Elongation, H 1000, minimum (Bibus datasheet)
    value: 10
    unit: '%'
    scope: material
    conditions:
      condition: H1000
      basis: minimum, room temperature
    method: Minimum value printed under the heading Typical mechanical properties (room temperature)
    status: ground
    source: bibus
    where: Typical mechanical properties table, row H1000, column Elongation, printed as min. 10 %
  - benchmark: hardness_rockwell_c
    label: Hardness, Rockwell C, H 1000, typical longitudinal (HiTemp Metals datasheet)
    value: 45
    unit: HRC
    scope: material
    conditions:
      condition: H 1000
      form: typical longitudinal
      basis: typical
    method: Typical value printed in a supplier datasheet; benchmark name is not in the canonical list (see gaps)
    status: ground
    source: hightempmetals
    where: Typical Longitudinal Room-Temperature Mechanical Properties table, row H 1000, column Rockwell C
  - benchmark: charpy_impact_energy
    label: Charpy V-notch impact energy, H 1000, typical longitudinal (HiTemp Metals datasheet)
    value: 41
    unit: J
    scope: material
    conditions:
      condition: H 1000
      form: typical longitudinal
      basis: typical
      test: Charpy V-notch
      unit_in_source: ft-lb / J
    method: Typical value printed in a supplier datasheet; benchmark name is not in the canonical list (see gaps)
    status: ground
    source: hightempmetals
    where: Typical Longitudinal Room-Temperature Mechanical Properties table, row H 1000, column Charpy V-Notch (ft-lb / J), printed as 30 / 41
  - benchmark: charpy_impact_energy
    label: Charpy V-notch impact energy, H 950, typical longitudinal (HiTemp Metals datasheet)
    value: 27
    unit: J
    scope: material
    conditions:
      condition: H 950
      form: typical longitudinal
      basis: typical
      test: Charpy V-notch
      unit_in_source: ft-lb / J
    method: Typical value printed in a supplier datasheet; benchmark name is not in the canonical list (see gaps)
    status: ground
    source: hightempmetals
    where: Typical Longitudinal Room-Temperature Mechanical Properties table, row H 950, column Charpy V-Notch (ft-lb / J), printed as 20 / 27
corrosion:
  - environment: Marine atmosphere, strip tested at the Kure Beach site
    headline: The datasheet reports a high level of resistance to stress-corrosion cracking in marine tests.
    effect: 'Quoted from the datasheet: ''Numerous tests representing a marine environment have shown the alloy to have a high level of resistance to stress-corrosion cracking.'' The datasheet''s table of results is titled ''Typical Stress-Corrosion-Cracking Resistance in an Atmospheric Marine Environment''. Its individual values were not transcribed, because the extracted table text was not reliable.'
    rating: low
    conditions:
      specimen: strip
      site: 80-ft lot, Kure Beach (as printed)
      basis: qualitative statement and table title
    source: hightempmetals
    where: Corrosion Resistance section and the Stress-Corrosion-Cracking Table title
  - environment: Salt fog, 5 weight percent
    headline: In condition H 950, rusting resistance is said to be similar to Type 304 in salt fog.
    effect: 'Quoted: ''rusting resistance similar to that of Type 304 Stainless in 5 weight percent salt fog'', for condition H 950.'
    rating: low
    conditions:
      condition: H 950
      test: 5 weight percent salt fog
    source: hightempmetals
    where: Corrosion Resistance section, first bullet
  - environment: Strongly oxidizing and reducing acids, and atmospheric exposure
    headline: General corrosion resistance approaches Type 304, and is greatest in the fully hardened condition.
    effect: 'Quoted: ''the general-corrosion resistance of PH 13-8 Mo stainless approaches that of Type 304'' under strongly oxidizing and reducing acids and atmospheric exposures. The same section says the alloy''s general-corrosion resistance is ''greatest in the fully hardened condition''.'
    rating: low
    conditions:
      exposure: strongly oxidizing and reducing acids and atmospheric exposures
    source: hightempmetals
    where: Corrosion Resistance section, general-corrosion bullets
  - environment: Air, passive film of chromium oxide
    headline: Stainless steels in general resist corrosion through a chromium oxide film; the rule is not specific to this grade.
    effect: Wikipedia says stainless steel's resistance to corrosion comes from its chromium content of 10.5% or more, which forms a passive film of chromium oxide that blocks oxygen from reaching the steel. The article is a general account of stainless steels and does not give a value for this grade.
    rating: low
    conditions:
      basis: general account of stainless steels
    source: wikipedia-stainless
    where: Opening section of the Stainless steel article
  - environment: Surfaces with scale or foreign particles
    headline: Scale and foreign particles reduce corrosion resistance, so finished parts should be passivated.
    effect: 'Quoted: ''For optimum corrosion resistance, surfaces must be free of scale and foreign particles and finished parts should be passivated.'' The datasheet gives no rate for an unclean surface.'
    rating: unknown
    conditions:
      basis: qualitative statement
    source: hightempmetals
    where: Corrosion Resistance section, last bullet
risks:
  hazards:
    - text: PubChem's record for nickel (CID 935) gives the GHS hazard statements H317 (may cause an allergic skin reaction), H351 (suspected of causing cancer), H372 (causes damage to organs through prolonged or repeated exposure) and H412 (harmful to aquatic life with long lasting effects) in its first notifier entries, with the signal word Danger and the pictograms GHS07 and GHS08. These codes are for nickel as an element, because no safety data sheet for PH 13-8 Mo was read.
      ghs:
        - H317
        - H351
        - H372
        - H412
      source: pubchem-nickel
      where: GHS Classification section, first notifier entries (signal word, pictograms and hazard statements)
  failure_risks:
    - mode: Stress-corrosion cracking of under-aged parts
      trigger: Ageing below 1000°F (538°C), which the datasheet says is the minimum for best resistance to stress-corrosion cracking
      consequence: The datasheet suggests a minimum ageing temperature of 1000°F (538°C) for best resistance to stress-corrosion cracking. It gives no failure rate for under-aged parts.
      severity: moderate
      source: hightempmetals
      where: Corrosion Resistance section, aging recommendation
    - mode: Lower impact toughness in the H 950 condition
      trigger: Choosing condition H 950 over H 1000 where impact energy matters
      consequence: Typical Charpy V-notch energy is 27 J in condition H 950 against 41 J in condition H 1000 (datasheet). Yield strength in H 950 is also higher, so the choice is a trade-off.
      severity: low
      source: hightempmetals
      where: Typical Longitudinal Room-Temperature Mechanical Properties table, rows H 950 and H 1000
    - mode: Welded joints in marine service
      trigger: Welding without a suitable filler or aged condition
      consequence: The datasheet suggests a standard austenitic filler such as E/ER308L where high weld strength is not needed. It does not report weld performance in marine tests in the text it gives.
      severity: low
      source: hightempmetals
      where: Applications and Uses text, welding filler paragraph
  side_effects:
    - text: The datasheet prints magnetic permeability for condition H 950 of 52 at 10.5 Oe, rising to 127 at 54.7 Oe, so the alloy is magnetic in this condition.
      affects: Use near magnetometers or other magnetic sensors
      source: hightempmetals
      where: Other Printed Values section, magnetic permeability
  handling:
    - text: Passivate finished parts and keep their surfaces free of scale and foreign particles (datasheet).
      source: hightempmetals
      where: Corrosion Resistance section, last bullet
    - text: Age at a minimum of 1000°F (538°C) for the best stress-corrosion resistance (datasheet).
      source: hightempmetals
      where: Corrosion Resistance section, aging recommendation
    - text: Where high weld strength is not needed, use a standard austenitic filler such as E/ER308L (datasheet).
      source: hightempmetals
      where: Applications and Uses text, welding filler paragraph
  mitigations: []
uses:
  - application: mechanisms
    device: Valve parts, fittings and shafts
    example: The datasheet says the alloy has been used for valve parts, fittings, cold-headed and machined fasteners, and shafts.
    source: hightempmetals
    where: Applications and Uses text
  - application: structures
    device: Aircraft components, nuclear reactor components and petrochemical parts
    example: The datasheet lists aircraft components, nuclear reactor components and petrochemical applications, and says the alloy should be considered where high strength, toughness and corrosion resistance are needed.
    source: hightempmetals
    where: Applications and Uses text
supply:
  - subject: Nickel (mine production)
    producers:
      - country: Indonesia
        share_percent: 66.7
        year: 2025
      - country: Philippines
        share_percent: 6.9
        year: 2025
      - country: Russia
        share_percent: 5.1
        year: 2025
      - country: Canada
        share_percent: 3.6
        year: 2025
      - country: New Caledonia
        share_percent: 3.6
        year: 2025
    critical_lists: []
    recycling: 'USGS: most secondary nickel was in the form of nickel content of stainless-steel scrap, and nickel recovered from scrap accounted for approximately 60% of apparent consumption in 2025.'
    substitutes:
      - 'USGS: low-nickel, duplex, or ultrahigh-chromium stainless steels have been substituted for austenitic grades in construction.'
    source: usgs-nickel-2026
    where: World Mine Production and Reserves table, 2025e world total 3,900,000 (metric tons, nickel content); country shares calculated by Space Mushroom from the printed 2025e values; Recycling; Substitutes; Domestic Production and Use (stainless and alloy steel typically more than 85% of domestic consumption).
  - subject: Chromium (mine production, chromite ore)
    producers:
      - country: South Africa
        share_percent: 45.1
        year: 2025
      - country: Turkey
        share_percent: 17.6
        year: 2025
      - country: Kazakhstan
        share_percent: 13.7
        year: 2025
      - country: India
        share_percent: 5.9
        year: 2025
      - country: Zimbabwe
        share_percent: 3.9
        year: 2025
    critical_lists: []
    substitutes: []
    source: usgs-chromium-2026
    where: World Mine Production and Reserves table, 2025e world total 51,000 (gross weight, metric tons); shares calculated by Space Mushroom from South Africa 23,000, Turkey 9,000, Kazakhstan 7,000, India 3,000 and Zimbabwe 2,000. The text read here prints no critical-mineral list entry.
  - subject: Molybdenum (mine production)
    producers:
      - country: China
        share_percent: 37.3
        year: 2025
      - country: Chile
        share_percent: 16.2
        year: 2025
      - country: United States
        share_percent: 15.4
        year: 2025
      - country: Peru
        share_percent: 15
        year: 2025
      - country: Mexico
        share_percent: 6.5
        year: 2025
    critical_lists: []
    substitutes: []
    source: usgs-molybdenum-2026
    where: 'World Mine Production and Reserves table, 2025e world total 260,000 (metric tons); shares calculated by Space Mushroom from the printed 2025e values. Events text: ''China, Chile, the United States, Peru, and Mexico, in descending order of production, accounting for 90% of total global production''.'
documents:
  - title: PH 13-8 Mo technical data, HiTemp Metals
    type: datasheet
    url: https://www.hightempmetals.com/techdata/hitemp13-8MOdata.php
  - title: PH 13-8 Mo | 1.4534 technical data, Bibus Metals
    type: datasheet
    url: https://sd-metals.bibus.com/de-en/materials/itm/PH-13-8-Mo-1-4534/
  - title: 'USGS Mineral Commodity Summaries 2026: Nickel'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-nickel.pdf
    year: 2026
  - title: 'USGS Mineral Commodity Summaries 2026: Chromium'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-chromium.pdf
    year: 2026
  - title: 'USGS Mineral Commodity Summaries 2026: Molybdenum'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-molybdenum.pdf
    year: 2026
  - title: 'PubChem compound record: Nickel (CID 935), GHS classification'
    type: database
    url: https://pubchem.ncbi.nlm.nih.gov/compound/Nickel
  - title: 'Wikipedia: Stainless steel'
    type: database
    url: https://en.wikipedia.org/wiki/Stainless_steel
  - title: 'Wikipedia: Precipitation hardening'
    type: database
    url: https://en.wikipedia.org/wiki/Precipitation_hardening
gaps:
  - No EN steel name (the X5CrNiMo-style name) is printed on the Bibus page or the HiTemp Metals page, so no EN name is recorded; the EN number 1.4534 is recorded from the Bibus header.
  - Modulus of elasticity and modulus of rigidity are printed only in exponent form (28.3 x 10³ ksi and 195 x 10³ MPa on the HiTemp Metals page), so they are left out.
  - Specific heat, a melting range and fracture toughness are not printed on either datasheet that was read.
  - 'The two datasheets differ on the coefficient of thermal expansion: 13 μm/m - °C at 20 to 100 °C (Bibus) and 10.8 10⁻⁶/K at 21 to 204 °C in condition H 1000 (HiTemp Metals). Both are recorded; neither is treated as the corrected value.'
  - The two datasheets differ on the composition maxima for manganese (0.20 Bibus, 0.10 HiTemp Metals) and nitrogen (0.10 Bibus, 0.01 HiTemp Metals). Both are recorded in identity.where.
  - Typical values (HiTemp Metals, longitudinal) and minimum values (Bibus) are on different bases. Both are recorded, side by side, under their own conditions.
  - The HiTemp Metals stress-corrosion table could not be transcribed reliably from the extracted text, so its individual results (applied stresses and days to failure) are not recorded; only the qualitative statements and the aging minimum are.
  - The datasheet's stress-corrosion note gives a solution-treatment step of 1700°F for 15 minutes for the H 950 rows; a full heat-treatment cycle was not opened, so only the aging minimum is recorded.
  - Hardness and impact energy use benchmark names not in the canonical list (hardness_rockwell_c and charpy_impact_energy); the values are recorded under those names.
  - No safety data sheet for PH 13-8 Mo was found or read. The hazard codes recorded are PubChem's codes for nickel as an element, not for this alloy.
  - The chromium and molybdenum USGS texts read here print no critical-mineral list entry, so critical_lists is left empty for them. The nickel text also prints none.
  - No atomic weights are recorded for the recipe parts; the composition is recorded as printed limits.
  - No flight data, outgassing, atomic-oxygen or radiation results for this alloy were found in the sources read.
  - The AMS 5629 specification text itself was not opened; the AMS number is recorded from the Bibus header only.
  - Launch-vehicle hardware use, named in the project's plan entry, is not printed on either datasheet read, so it is not recorded as a use.
  - Strength at elevated temperature, and the effect of cold work, were not found in the sources read.
sources:
  hightempmetals:
    title: PH 13-8 Mo technical data, HiTemp Metals (supplier datasheet)
    url: https://www.hightempmetals.com/techdata/hitemp13-8MOdata.php
    kind: datasheet
    license: Supplier technical data page (cited, not reproduced)
  bibus:
    title: PH 13-8 Mo | 1.4534 technical data, Bibus Metals (supplier datasheet)
    id: EN 1.4534, UNS S13800, AMS 5629
    url: https://sd-metals.bibus.com/de-en/materials/itm/PH-13-8-Mo-1-4534/
    kind: datasheet
    license: Supplier technical data page (cited, not reproduced)
  usgs-nickel-2026:
    title: 'Mineral Commodity Summaries 2026: Nickel (USGS)'
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-nickel.pdf
    year: 2026
    kind: report
    license: public domain (USGS)
  usgs-chromium-2026:
    title: 'Mineral Commodity Summaries 2026: Chromium (USGS)'
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-chromium.pdf
    year: 2026
    kind: report
    license: public domain (USGS)
  usgs-molybdenum-2026:
    title: 'Mineral Commodity Summaries 2026: Molybdenum (USGS)'
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-molybdenum.pdf
    year: 2026
    kind: report
    license: public domain (USGS)
  pubchem-nickel:
    title: 'PubChem compound record: Nickel, CID 935, including GHS classification'
    id: CID 935
    url: https://pubchem.ncbi.nlm.nih.gov/compound/Nickel
    kind: database
    license: PubChem (NCBI), public domain; classification sections attributed to notifiers
  wikipedia-stainless:
    title: Stainless steel (Wikipedia)
    url: https://en.wikipedia.org/wiki/Stainless_steel
    kind: web
    license: CC BY-SA 4.0 (cited, not reproduced)
  wikipedia-precipitation-hardening:
    title: Precipitation hardening (Wikipedia)
    url: https://en.wikipedia.org/wiki/Precipitation_hardening
    kind: web
    license: CC BY-SA 4.0 (cited, not reproduced)
license: CC-BY-4.0
updated: '2026-11-01'
review:
  status: draft
  method: assistant
  checked_values: 22
  unreachable: 0
  caveats: 5
  note: 'Values were read by an AI assistant on 2026-11-01 from the two supplier datasheets and the USGS 2026 summaries named in each entry. Caveats: the two datasheets give typical and minimum strengths on different bases; their thermal expansion values differ; the stress-corrosion table could not be transcribed reliably; the hazard codes are for nickel, not for the alloy; the Charpy and hardness benchmark names are not canonical.'
story:
  risk_groups:
    - title: For people
      lead: No safety data sheet for this alloy was read. The hazard codes in PubChem are for nickel as an element.
      level: 1
      verdict: Nickel hazard codes only, not the alloy's own SDS
      points:
        - label: The alloy
          line: The PubChem nickel record gives H317 (may cause an allergic skin reaction), H351 (suspected of causing cancer) and H372 (damage to organs with repeated exposure), with the signal word Danger.
        - label: Welding and surfaces
          line: The datasheet suggests E/ER308L filler where high weld strength is not needed, and asks that finished parts be passivated.
    - title: If it fails
      lead: The failure routes in the sources are stress-corrosion cracking of under-aged parts and lower impact toughness in condition H 950.
      points:
        - label: Under-aged parts
          line: The datasheet suggests a minimum ageing temperature of 1000°F (538°C) for best resistance to stress-corrosion cracking. It gives no failure rate for under-aged parts.
        - label: Toughness
          line: Typical Charpy V-notch energy is 27 J in condition H 950 and 41 J in condition H 1000, so the higher-strength condition is the less tough one.
    - title: Handling and storage
      points:
        - label: Surfaces
          line: Keep surfaces free of scale and foreign particles, and passivate finished parts (HiTemp Metals datasheet).
        - label: Condition
          line: Specify the condition (H 950, H 1000 or H 1050) on every order, because strength and toughness change with it.
  why: 'Precipitation hardening, also called age hardening, is a heat treatment that raises the yield strength of malleable materials (Wikipedia). PH 13-8 Mo is a precipitation-hardening stainless steel, chosen where a stainless part needs high strength and toughness together. The Bibus datasheet gives a minimum yield strength of 1413 MPa in condition H950 and a minimum tensile strength of 1517 MPa. The HiTemp Metals datasheet gives a typical yield strength of 1449 MPa for the same condition. Its aerospace and valve uses rest on the combination: a Charpy V-notch energy of 27 J in H 950 and 41 J in H 1000.'
  uses:
    - where: Valve parts, fittings and shafts
      line: The HiTemp Metals datasheet says the alloy has been used for valve parts, fittings, cold-headed and machined fasteners, and shafts.
    - where: Aircraft and reactor parts
      line: The same datasheet lists aircraft components, nuclear reactor components and petrochemical applications.
  can_do:
    - label: Carry load
      value: 1449 MPa yield (H 950, typical)
      benchmark: yield_strength
      line: The typical yield strength is 1449 MPa in condition H 950 (HiTemp Metals). The Bibus minimum for the same condition is 1413 MPa.
    - label: Resist impact
      value: 41 J Charpy (H 1000, typical)
      benchmark: charpy_impact_energy
      line: Charpy V-notch energy is 41 J in condition H 1000 and 27 J in condition H 950 (HiTemp Metals, typical longitudinal values).
    - label: Carry heat
      value: 14.0 W/m-K at 100 °C
      benchmark: thermal_conductivity
      line: Thermal conductivity is 14.0 W/m-K at 100 °C in condition A (HiTemp Metals), and 12.8 W/m - °C at 20 °C (Bibus). The two sources test at different temperatures.
    - label: Weight
      value: 7.76 g/cm3
      benchmark: density
      line: Density is 7.76 g/cm3 in the Bibus datasheet, with no condition printed.
    - label: Melting
      value: 1404 °C
      benchmark: melting_point
      line: The Bibus datasheet gives a single melting point of 1404 °C, with no range.
    - label: Marine stress-corrosion
      value: high resistance, qualitative
      line: The HiTemp Metals datasheet reports a high level of resistance to stress-corrosion cracking in marine tests, without a numeric threshold.
  compare: 'Against Type 304 stainless steel, the HiTemp Metals datasheet says PH 13-8 Mo''s general-corrosion resistance approaches that of Type 304, and that its rusting resistance in 5 weight percent salt fog is similar to Type 304 in condition H 950. The reason to choose PH 13-8 Mo is strength: its typical yield strength is 1449 MPa in H 950, against the Bibus minimum of 1413 MPa for the same condition. The two datasheets use different bases, so read the table rows as examples, not a ranking.'
  compare_rows:
    - label: Yield strength
      benchmark: yield_strength
    - label: Thermal conductivity
      benchmark: thermal_conductivity
    - label: Density
      benchmark: density
  handling:
    - Passivate finished parts and keep their surfaces free of scale and foreign particles (HiTemp Metals datasheet).
    - Age at a minimum of 1000°F (538°C) for the best stress-corrosion resistance (HiTemp Metals datasheet).
    - Where high weld strength is not needed, use a standard austenitic filler such as E/ER308L (HiTemp Metals datasheet).
  good_for:
    - 'Strong stainless parts in marine or humid air: the datasheet reports a high level of resistance to stress-corrosion cracking in marine tests.'
    - Fasteners and valve parts in conditions H 950 to H 1050, the uses the datasheet lists.
    - 'Tough high-strength parts: 41 J Charpy V-notch energy in condition H 1000.'
  watch_out:
    - 'Strength depends on condition: the Bibus minimum yield strength falls from 1413 MPa at H950 to 1138 MPa at H1050.'
    - Under-aged parts are at risk of stress-corrosion cracking, since the datasheet suggests a minimum ageing temperature of 1000°F (538°C).
    - 'The two datasheets disagree on thermal expansion: 13 μm/m - °C at 20 to 100 °C (Bibus) against 10.8 at 21 to 204 °C in H 1000 (HiTemp Metals).'
    - No flight, outgassing, atomic-oxygen or radiation data for this alloy were found in any source read.
  verdict: PH 13-8 Mo is a precipitation-hardening stainless steel with a typical yield strength of 1449 MPa in condition H 950 (HiTemp Metals) and a Bibus minimum of 1413 MPa. Its toughness rises as the condition moves from H 950 to H 1000, while yield strength falls slightly. Its stress-corrosion resistance in marine tests is described qualitatively as high. This profile has no space-environment data for the alloy, and no stress-corrosion table values, because that table could not be transcribed reliably.
  recipe:
    line: PH 13-8 Mo is an iron-based precipitation-hardening stainless steel. Chromium, nickel, molybdenum and aluminium are the main alloying elements, and carbon, manganese, silicon, nitrogen and phosphorus are kept low. Precipitation hardening is a heat treatment that raises strength by forming fine particles in the metal (Wikipedia). The Bibus limits are in the identity block.
    parts:
      - name: Iron
        symbol: Fe
        share_note: balance (Bibus prints Rest)
        role: The matrix that the other elements are added to.
      - name: Chromium
        symbol: Cr
        share_percent: 12.25
        share_high: 13.25
        role: Gives the stainless corrosion resistance; Wikipedia says 10.5% or more forms the passive film.
      - name: Nickel
        symbol: Ni
        share_percent: 7.5
        share_high: 8.5
        role: Alloying element printed in the composition table; its role in this grade is not described in the sources read.
      - name: Molybdenum
        symbol: Mo
        share_percent: 2
        share_high: 2.5
        role: Alloying element printed in the composition table; its role in this grade is not described in the sources read.
      - name: Aluminium
        symbol: Al
        share_percent: 0.9
        share_high: 1.35
        role: Alloying element printed in the composition table; the datasheets do not say how it forms the hardening particles.