Iron (pure and ingot iron)
Fe · CAS 7439-89-6 · cubic, Im-3m
Iron (Fe) is a ferromagnetic metal with a density of 7.874 g/cm3 and a melting point of 1538 °C, per periodictable.com.
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.
Mass estimate
7.874 g/cm³
Magnetic state
1043 K
Heat conduction
79 W/(m K)
Magnetic saturation
2.15 T
Recipe, share of the weight
- Fe 100.0%Iron
Best for
Magnetic shielding and soft magnetic parts where the duty is direct current or low frequency (vendor description and CERN review)
Weakest at
Low electrical resistivity in alternating-current use (CERN review), and oxidation in humid air under irradiation (Lapuerta et al.)
Risk at a glance
- People None found. Solid iron: no hazard in sources read
- If it fails Moderate. Ignition of finely divided iron
- Corrosion Moderate. In humid air at 45 % relative humidity, iron oxidation under proton irradiation was strongly enhanced, with oxygen reaching up to 60 at.%.
Quick facts: Iron (pure and ingot iron)
| Property | Value | Basis |
|---|---|---|
| Density | 7.87 g/cm³ | 1 sourced value |
| Young's modulus | 211 GPa | 1 sourced value |
| Hardness (Brinell) | 490 MPa | 1 sourced value |
| Thermal conductivity | 79 to 80 W/(m·K) | 2 sourced values across conditions |
| Thermal expansion (CTE) | 11.8 ppm/K | 1 sourced value |
| Melting point | 1,538 °C | 1 sourced value |
| Specific heat | 449 J/(kg·K) | 1 sourced value |
What is the density of Iron?
Iron has a density of 7.87 g/cm³. The source and test conditions are listed in the properties table on this page.
What is the thermal conductivity of Iron?
Iron has a thermal conductivity of 79 to 80 W/(m·K). 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 coefficient of thermal expansion of Iron?
Iron has a coefficient of thermal expansion of 11.8 ppm/K. The source and test conditions are listed in the properties table on this page.
What is the melting point of Iron?
Iron has a melting point of 1,538 °C. The source and test conditions are listed in the properties table on this page.
What is the Young's modulus of Iron?
Iron has a Young's modulus of 211 GPa. The source and test conditions are listed in the properties table on this page.
What is Iron used for?
Uses recorded in the sources include Magnetic shielding foil; Soft ferromagnetic core and shield materials (the class named in the review).
Why it exists
Iron (Fe) is a ferromagnetic metal. Its density is 7.874 g/cm3 and its melting point is 1538 °C, per periodictable.com. Iron is used for magnetic shielding and for soft magnetic parts, and a supplier sells high-purity soft ingot iron for those uses. The CERN review that describes soft magnetic materials warns that very pure iron is not suited to alternating-current use, so the purity and duty of the part decide whether iron is a good fit.
Where it's used
Magnetic shielding
Goodfellow sells ARMCO soft ingot iron foil at 99.8% purity and describes it as widely used in magnetic shielding, flux return paths, transformer laminations and low-temperature magnetic measurements. These are vendor claims, not test data.
Soft magnetic cores and shields
A CERN review lists transformer cores and shielding of magnetic fields among the uses of soft ferromagnetic materials. The same review says very pure iron is unsuitable for ac applications.
Recipe
Fe
Iron is a chemical element with the symbol Fe and atomic number 26. The sources describe the element itself, so the recipe is a single component. Iron ore is refined into iron and steel at blast furnaces and basic oxygen furnaces (USGS).
| Ingredient | Atoms per unit | Share of the weight | What it does |
|---|---|---|---|
| Iron Fe | 1 | 100.0% | The whole element. It has a body-centered cubic crystal structure and is ferromagnetic below its Curie temperature of 1043 K. |
Weight shares are calculated from standard atomic weights.
What it can do
Mass estimate
7.874 g/cm³
measured
Give a density of 7.874 g/cm3 for mass estimates of solid pieces (periodictable.com).
Magnetic state
1043 K
measured
Stay below its Curie temperature of 1043 K to remain ferromagnetic (periodictable.com).
Heat conduction
79 W/(m K)
measured
Conduct heat at 79 W/(m K) on periodictable.com or 80 W m-1 K-1 on WebElements; the two pages differ by one unit.
Magnetic saturation
2.15 T
measured
Carry a saturation magnetization of 2.15 T; the CERN review says purity does not strongly change it.
How it compares
The two reference pages give one value per property for iron, and where they differ both are kept. Thermal conductivity reads 79 W/(m K) on periodictable.com and 80 W m-1 K-1 on WebElements. The magnetic figures and the Curie temperature of 1043 K come from periodictable.com and the CERN review, which gives 2.15 T for saturation magnetization. No comparison with other metals is made here, because the sources for other metals are not part of this profile.
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.
| Measurement | Iron (pure and ingot iron) |
|---|---|
| Thermal behavior and safety | |
| melting point | 1538 °C1 |
| specific heatValue printed on the element data page | 449 J/(kg K) |
| Thermal conductivityValue printed on the element data page | 79 W/(m K)2 |
| Thermal conductivity | 80 W m-1 K-13 |
| heat of fusionValue printed on the element data page | 13.8 kJ/mol |
| Physical and electrical | |
| DensityValue printed on the element data page | 7.874 g/cm³ |
| brinell hardnessValue printed on the element data page | 490 MPa |
| vickers hardnessValue printed on the element data page | 608 MPa |
| mohs hardness | 4 -7 |
| Temperature behavior | |
| curie temperature | 1043 K8 |
| Other measurements | |
| boiling pointValue printed on the element data page | 2861 °C |
| elastic modulus | 211 GPa4 |
| shear modulusValue printed on the element data page | 82 GPa |
| bulk modulusValue printed on the element data page | 170 GPa |
| poissons ratio | 0.29 -5 |
| Thermal expansion (CTE) | 1.18×10^-5 K-16 |
| speed of soundValue printed on the element data page | 4910 m/s |
| lattice constant | 286.6 pm9 |
| saturation magnetization | 2.15 T10 |
Why choose it, and why not
Good for
- Magnetic shielding stock where purity and soft magnetic behaviour matter (vendor description).
- Reference data for the element: density, melting point, elastic constants and Curie temperature from two reference pages.
Watch out for
- Very pure iron is unsuitable for alternating-current applications (CERN review).
- Iron powder is a flammable solid (H228) in the Fujifilm sheet and in some PubChem reports.
- The humidity data here come from an irradiation test, not from atmospheric rusting, which was not found in an open source.
Iron is well documented as an element, with density, melting point and elastic constants from two reference pages. Its magnetic use depends on purity and on keeping it out of alternating-current duty.
Used in space products
Space hardware whose maker names Iron (pure and ingot iron), with the part it is used for.
| Product | Where it is used |
|---|---|
| Hubble Space TelescopeNASA | Magnetic torquers (x4) |
Technical details
For scientists and researchers. Everything above comes from the record below: every number with its method, its conditions and its source.
Notes
The method, full conditions and any caveat for the numbered rows above.
| # | Measurement | Method | Conditions | Caveat |
|---|---|---|---|---|
| 1 | melting point | Value printed on the element data page (the page also prints 1811 K) | form elemental iron; the page names no grade or purity | — |
| 2 | Thermal conductivity | — | form elemental iron; temperature not stated on the page | WebElements prints 80 for the same property (next row); the two pages differ by one unit. |
| 3 | Thermal conductivity | Value printed on the WebElements physics page, Heat and conduction section | form elemental iron; temperature not stated on the page | Periodictable.com prints 79 W/(m K) for the same property (previous row). |
| 4 | elastic modulus | Value printed on the WebElements physics page, Elastic properties section (Young's modulus) | form elemental iron; temperature not stated on the page | — |
| 5 | poissons ratio | Value printed on the element data page (printed with no unit) | form elemental iron; temperature not stated on the page | — |
| 6 | Thermal expansion (CTE) | Value printed on the element data page in decimal form (WebElements prints the same property in exponent form, which is not used here) | form elemental iron; temperature range not stated on the page | — |
| 7 | mohs hardness | Value printed on the element data page (printed with no unit) | form elemental iron | — |
| 8 | curie temperature | Value printed on the element data page (magnetic properties section) | phase ferromagnetic solidform elemental iron | — |
| 9 | lattice constant | Value printed on the element data page (three equal lattice constants) | crystal body-centered cubictemperature not stated on the page | — |
| 10 | saturation magnetization | Value quoted in an open review; the review says saturation magnetization is not strongly influenced by purity | material iron, as quoted in a CERN review; purity not stated for this value | — |
Corrosion and compatibility
What happens when it meets other materials and environments.
| Environment | Concern | What happens |
|---|---|---|
| Humid air under 3 MeV proton irradiation at room temperature (a laboratory test, not an atmospheric exposure) | moderate | In humid air at 45 % relative humidity, iron oxidation under proton irradiation was strongly enhanced, with oxygen reaching up to 60 at.%.1 |
| # | Environment | Details | Test conditions |
|---|---|---|---|
| 1 | Humid air under 3 MeV proton irradiation at room temperature (a laboratory test, not an atmospheric exposure) | Lapuerta et al. irradiated a 10 µm iron foil of 99.85% purity. The oxygen profile rose strongly only in humid air; dry air and humid nitrogen left the oxygen amount unchanged. The authors note earlier work that found more iron corrosion during wet cycles than during dry ones. | exposure 3 MeV proton beam at 10 nA, room temperature, 45 % relative humiditymaterial iron foil, 10 µm thick, 99.85% purity |
Risks and side effects
Hazards to people, what happens when a cell overheats, and how the material is handled and stored.
For people
The solid metal is not described as hazardous in the sources read. PubChem's summary is mostly 'does not meet criteria', but the classified reports and the powder sheet show a flammable-solid hazard.
- Solid metal
- PubChem reports that 74.1% (4458 of 6013) of reports say the substance does not meet GHS hazard criteria.
- Powder
- A Fujifilm Wako sheet for iron powder gives H228 Flammable solid with signal word Warning.
If iron is a fine powder
Fine iron can ignite. Keep it away from strong oxidizing agents and use local exhaust indoors.
- Classification
- H228 Flammable solid appears in the powder sheet and in 15.5% of PubChem reports. H251 Self-heating appears in 21.2% of PubChem reports.
Test details
The original wording and numbers from the sources, for readers who want them.
Failure risks
| Failure | Trigger and consequence |
|---|---|
| Ignition of finely divided ironmoderate severity | Powder or fines in air (the form covered by the Fujifilm sheet)Flammable solid classification (H228) on the powder sheet; PubChem reports H251 Self-heating for 21.2% of reports. |
| Poor performance in alternating-current usemoderate severity | Very pure iron used in alternating-current applicationsThe CERN review states that very pure iron features high electrical conductivity and is unsuitable for ac applications. |
Handling and storage
- Avoid contact with strong oxidizing agents and with acidic and alkaline substances. Indoors, use a local exhaust system (Fujifilm sheet, powder).
Supply and geography
How common the raw materials are and where they come from.
Iron ore (the feedstock for pure iron)
- Top producers (2025)
- Australia 37.7%, Brazil 16.2%, India 11.9%, China 11.2%
- Recycling
- USGS iron ore chapter: Recycling: None. See the Iron and Steel Scrap chapter.
- Substitutes
- USGS: The only source of primary iron is iron ore; scrap, DRI and iron nuggets are used in electric arc furnaces and foundries.
Documents
Datasheets, safety data sheets, papers and standards you can open.
| Document | Type | Year |
|---|---|---|
| USGS Mineral Commodity Summaries 2026, Iron Ore | report | 2026 |
| PubChem: Iron (CID 23925), GHS classification summary | database | 2026 |
| Fujifilm Wako safety data sheet, Iron, Powder (revision 09-Feb-2023) | sds | 2023 |
| Physics and measurements of magnetic materials (CERN, arXiv 1103.1069) | paper | 2011 |
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: iron
spore_version: 0.2
family: iron
name: Iron (pure and ingot iron)
role: structural soft magnetic metal
category: metals
type: steels-and-stainless
summary: Iron (Fe) is a ferromagnetic metal with a density of 7.874 g/cm3 and a melting point of 1538 °C, per periodictable.com. Soft ingot iron is sold at high purity for magnetic shielding (Goodfellow), but a CERN review says very pure iron is unsuitable for alternating-current applications. The sources here describe the element, not a single ingot grade.
best_for: Magnetic shielding and soft magnetic parts where the duty is direct current or low frequency (vendor description and CERN review)
weakest_at: Low electrical resistivity in alternating-current use (CERN review), and oxidation in humid air under irradiation (Lapuerta et al.)
identity:
formula: Fe
cas: 7439-89-6
atomic_number: 26
crystal_system: cubic
space_group: Im-3m
source: periodictable-fe
where: 'Overview and Atomic dimensions and structure tables (periodictable.com: body-centered cubic, space group number 229); CAS from PubChem CID 23925'
properties:
- benchmark: density
value: 7.874
unit: g/cm3
scope: material
conditions:
phase: solid
form: elemental iron; the page names no grade or purity
method: Value printed on the element data page
status: ground
source: periodictable-fe
where: Bulk physical properties table, Density row
- benchmark: melting_point
value: 1538
unit: °C
scope: material
conditions:
form: elemental iron; the page names no grade or purity
method: Value printed on the element data page (the page also prints 1811 K)
status: ground
source: periodictable-fe
where: Thermal properties table, Melting Point row
- benchmark: boiling_point
value: 2861
unit: °C
scope: material
conditions:
form: elemental iron; the page names no grade or purity
method: Value printed on the element data page
status: ground
source: periodictable-fe
where: Thermal properties table, Boiling Point row
- benchmark: specific_heat
value: 449
unit: J/(kg K)
scope: material
conditions:
phase: solid
note: the page states this is the value for the solid phase
method: Value printed on the element data page
status: ground
source: periodictable-fe
where: Thermal properties table, Specific Heat row
- benchmark: thermal_conductivity
value: 79
unit: W/(m K)
scope: material
conditions:
form: elemental iron; temperature not stated on the page
method: Value printed on the element data page
status: ground
note: WebElements prints 80 for the same property (next row); the two pages differ by one unit.
source: periodictable-fe
where: Thermal properties table, Thermal Conductivity row
- benchmark: thermal_conductivity
value: 80
unit: W m-1 K-1
scope: material
conditions:
form: elemental iron; temperature not stated on the page
method: Value printed on the WebElements physics page, Heat and conduction section
status: ground
note: Periodictable.com prints 79 W/(m K) for the same property (previous row).
source: webelements-iron
where: Heat and conduction section, Thermal conductivity
- benchmark: elastic_modulus
value: 211
unit: GPa
scope: material
conditions:
form: elemental iron; temperature not stated on the page
method: Value printed on the WebElements physics page, Elastic properties section (Young's modulus)
status: ground
source: webelements-iron
where: Elastic properties section, Young's modulus
- benchmark: shear_modulus
value: 82
unit: GPa
scope: material
conditions:
form: elemental iron; temperature not stated on the page
method: Value printed on the element data page
status: ground
source: periodictable-fe
where: Bulk physical properties table, Shear Modulus row
- benchmark: bulk_modulus
value: 170
unit: GPa
scope: material
conditions:
form: elemental iron; temperature not stated on the page
method: Value printed on the element data page
status: ground
source: periodictable-fe
where: Bulk physical properties table, Bulk Modulus row
- benchmark: poissons_ratio
value: 0.29
unit: '-'
scope: material
conditions:
form: elemental iron; temperature not stated on the page
method: Value printed on the element data page (printed with no unit)
status: ground
source: periodictable-fe
where: Bulk physical properties table, Poisson Ratio row
- benchmark: cte
value: 0.0000118
unit: K-1
scope: material
conditions:
form: elemental iron; temperature range not stated on the page
method: Value printed on the element data page in decimal form (WebElements prints the same property in exponent form, which is not used here)
status: ground
source: periodictable-fe
where: Thermal properties table, Thermal Expansion row
- benchmark: brinell_hardness
value: 490
unit: MPa
scope: material
conditions:
form: elemental iron; the page names no grade, temper or purity
method: Value printed on the element data page
status: ground
source: periodictable-fe
where: Bulk physical properties table, Brinell Hardness row
- benchmark: vickers_hardness
value: 608
unit: MPa
scope: material
conditions:
form: elemental iron; the page names no grade, temper or purity
method: Value printed on the element data page
status: ground
source: periodictable-fe
where: Bulk physical properties table, Vickers Hardness row
- benchmark: mohs_hardness
value: 4
unit: '-'
scope: material
conditions:
form: elemental iron
method: Value printed on the element data page (printed with no unit)
status: ground
source: periodictable-fe
where: Bulk physical properties table, Mohs Hardness row
- benchmark: speed_of_sound
value: 4910
unit: m/s
scope: material
conditions:
form: elemental iron; temperature not stated on the page
method: Value printed on the element data page
status: ground
source: periodictable-fe
where: Bulk physical properties table, Speed of Sound row
- benchmark: curie_temperature
value: 1043
unit: K
scope: material
conditions:
phase: ferromagnetic solid
form: elemental iron
method: Value printed on the element data page (magnetic properties section)
status: ground
source: periodictable-fe
where: Magnetic properties table, Curie Point row
- benchmark: heat_of_fusion
value: 13.8
unit: kJ/mol
scope: material
conditions:
form: elemental iron
method: Value printed on the element data page
status: ground
source: periodictable-fe
where: Thermal properties table, Heat of Fusion row
- benchmark: lattice_constant
value: 286.65
unit: pm
scope: material
conditions:
crystal: body-centered cubic
temperature: not stated on the page
method: Value printed on the element data page (three equal lattice constants)
status: ground
source: periodictable-fe
where: Atomic dimensions and structure table, Lattice Constants row
- benchmark: saturation_magnetization
value: 2.15
unit: T
scope: material
conditions:
material: iron, as quoted in a CERN review; purity not stated for this value
method: Value quoted in an open review; the review says saturation magnetization is not strongly influenced by purity
status: ground
source: arxiv-sgobba-2011
where: Section 2.3 (High-purity iron), second paragraph
corrosion:
- environment: Humid air under 3 MeV proton irradiation at room temperature (a laboratory test, not an atmospheric exposure)
headline: In humid air at 45 % relative humidity, iron oxidation under proton irradiation was strongly enhanced, with oxygen reaching up to 60 at.%.
effect: Lapuerta et al. irradiated a 10 µm iron foil of 99.85% purity. The oxygen profile rose strongly only in humid air; dry air and humid nitrogen left the oxygen amount unchanged. The authors note earlier work that found more iron corrosion during wet cycles than during dry ones.
rating: moderate
conditions:
exposure: 3 MeV proton beam at 10 nA, room temperature, 45 % relative humidity
material: iron foil, 10 µm thick, 99.85% purity
source: lapuerta2005
where: Abstract; Results, oxygen profiles (Fig. 5)
risks:
hazards:
- text: PubChem's GHS summary for Iron (CID 23925) reports that 74.1% (4458 of 6013) of reports say the substance does not meet GHS hazard criteria. The reports that do classify it give H228 Flammable solid (15.5%) and H251 Self-heating (21.2%), with signal word Danger. The notified forms are not stated, so check the supplier's sheet for the form you handle.
ghs:
- H228
- H251
source: pubchem-iron
where: Safety and Hazards, GHS Classification (CID 23925)
- text: 'Fujifilm Wako safety data sheet for Iron, Powder (revision 09-Feb-2023): Flammable solids Category 2, signal word Warning, hazard statement H228 Flammable solid. This classification covers the powder, not solid ingot or foil.'
ghs:
- H228
source: fuji-iron-powder-sds
where: Hazard identification section (classification and signal word lines)
failure_risks:
- mode: Ignition of finely divided iron
trigger: Powder or fines in air (the form covered by the Fujifilm sheet)
consequence: Flammable solid classification (H228) on the powder sheet; PubChem reports H251 Self-heating for 21.2% of reports.
severity: moderate
source: fuji-iron-powder-sds
where: Hazard identification section
- mode: Poor performance in alternating-current use
trigger: Very pure iron used in alternating-current applications
consequence: The CERN review states that very pure iron features high electrical conductivity and is unsuitable for ac applications.
severity: moderate
source: arxiv-sgobba-2011
where: Section 2.3 (High-purity iron), first paragraph
handling:
- text: Avoid contact with strong oxidizing agents and with acidic and alkaline substances. Indoors, use a local exhaust system (Fujifilm sheet, powder).
source: fuji-iron-powder-sds
where: Handling and exposure-control text
uses:
- application: electronics-and-chips
device: Magnetic shielding foil
example: Goodfellow sells ARMCO soft ingot iron foil at 99.8% purity (2N8) and describes it as widely used in magnetic shielding, flux return paths, transformer laminations and low-temperature magnetic measurements. These are vendor claims, not test data.
source: goodfellow-armco-foil
where: 'Product page: purity line and description text'
- application: electronics-and-chips
device: Soft ferromagnetic core and shield materials (the class named in the review)
example: A CERN review lists transformer cores and shielding of magnetic fields among soft ferromagnetic material uses, and says very pure iron is unsuitable for ac applications.
source: arxiv-sgobba-2011
where: Soft magnetic materials paragraph before Section 2.3; Section 2.3
supply:
- subject: Iron ore (the feedstock for pure iron)
producers:
- country: Australia
share_percent: 37.7
year: 2025
- country: Brazil
share_percent: 16.2
year: 2025
- country: India
share_percent: 11.9
year: 2025
- country: China
share_percent: 11.2
year: 2025
recycling: 'USGS iron ore chapter: Recycling: None. See the Iron and Steel Scrap chapter.'
substitutes:
- 'USGS: The only source of primary iron is iron ore; scrap, DRI and iron nuggets are used in electric arc furnaces and foundries.'
source: usgs-mcs2026-iron-ore
where: World Mine Production table, usable ore, 2025e (world total 2,600,000 thousand t; shares calculated by Space Mushroom); Recycling and Substitutes
media: []
documents:
- title: USGS Mineral Commodity Summaries 2026, Iron Ore
type: report
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-iron-ore.pdf
year: 2026
- title: 'PubChem: Iron (CID 23925), GHS classification summary'
type: database
url: https://pubchem.ncbi.nlm.nih.gov/compound/23925
year: 2026
- title: Fujifilm Wako safety data sheet, Iron, Powder (revision 09-Feb-2023)
type: sds
url: https://labchem-wako.fujifilm.com/sds/W01W0109-0075JGHEEN.pdf
year: 2023
- title: Physics and measurements of magnetic materials (CERN, arXiv 1103.1069)
type: paper
url: https://arxiv.org/pdf/1103.1069
year: 2011
gaps:
- No UNS, EN or other grade designation for pure iron was found in a source read in this run. The ARMCO trade name covers different purity grades (CERN review, Table 1 note), so it is not listed as a designation.
- Electrical resistivity and electrical conductivity for iron are printed only in exponent form on both element pages, so they are left out.
- Thermal expansion on WebElements is printed only in exponent form; the periodictable.com decimal form is used instead.
- Melting point, boiling point and specific heat on WebElements were not printed as values on the fetched page; periodictable.com values are used.
- Atmospheric rusting rate against relative humidity was not found in an open source read in this run (the Cardiff ORCA paper returned HTTP 403 and the arXiv humid-air paper is an irradiation test).
- The Sigma-Aldrich iron SDS (product 413054) timed out, so only the Fujifilm powder sheet and PubChem are used for hazards. No hazard sheet for solid ingot or foil was read.
- No space flight, vacuum or radiation result for iron as a material was found, and no space-related use of iron was found in the sources read.
- Abundance in the Earth's crust was not read in a source fetched in this run.
- Critical-mineral list status for iron metal was not checked in this run (the USGS iron ore chapter was read, not the 2025 list page).
- Curie temperature, heat of fusion, lattice constant, speed of sound, Mohs hardness and saturation magnetization are not in the canonical property list; snake_case names are used for them.
- Density on WebElements is printed in kg m-3 (7874) and was not used separately; periodictable.com gives 7.874 g/cm3.
sources:
webelements-iron:
title: 'Iron: 26Fe, physical properties (WebElements)'
id: WebElements iron physics page
url: https://www.webelements.com/iron/physics.html
year: 2026
kind: web
license: WebElements, cited not reproduced
periodictable-fe:
title: 'Iron (Fe, element 26): data (Periodic Table, periodictable.com)'
id: periodictable.com, element 026 data page
url: https://periodictable.com/Elements/026/data.html
year: 2026
kind: database
license: periodictable.com, cited not reproduced
usgs-mcs2026-iron-ore:
title: Mineral Commodity Summaries 2026, Iron Ore
id: USGS MCS 2026, February 2026
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-iron-ore.pdf
year: 2026
kind: report
license: public domain (USGS)
pubchem-iron:
title: PubChem compound record, Iron (CID 23925), GHS classification
id: CID 23925; CAS 7439-89-6
url: https://pubchem.ncbi.nlm.nih.gov/compound/23925
year: 2026
kind: database
license: public domain (NCBI)
arxiv-sgobba-2011:
title: Physics and measurements of magnetic materials (S. Sgobba, CERN)
id: arXiv:1103.1069
url: https://arxiv.org/pdf/1103.1069
year: 2011
kind: paper
license: arXiv, as posted
goodfellow-armco-foil:
title: ARMCO soft ingot iron foil (Goodfellow product page)
id: Goodfellow, ARMCO soft ingot iron foil
url: https://www.goodfellow.com/usa/armco-soft-ingot-iron-foil-group
year: 2026
kind: web
license: vendor page, cited not reproduced
fuji-iron-powder-sds:
title: Safety data sheet, Iron, Powder (Fujifilm Wako Pure Chemical, revision 6.02)
id: Revision date 09-Feb-2023; revision number 6.02
url: https://labchem-wako.fujifilm.com/sds/W01W0109-0075JGHEEN.pdf
year: 2023
kind: datasheet
license: supplier document, linked not reproduced
lapuerta2005:
title: Use ion beam techniques to study the coupling between air and its relative humidity on iron corrosion under irradiation
id: arXiv:physics/0509120
url: https://arxiv.org/pdf/physics/0509120
year: 2005
kind: paper
license: arXiv, as posted
license: CC-BY-4.0
updated: '2026-11-01'
review:
status: draft
method: assistant
checked_values: 19
unreachable: 2
caveats: 3
note: Read by an AI assistant on 2026-11-01 from WebElements, periodictable.com, USGS, PubChem, a CERN review, a vendor page, a supplier sheet and an open paper. The Sigma-Aldrich SDS and the Cardiff ORCA paper could not be read.
story:
recipe:
line: Iron is a chemical element with the symbol Fe and atomic number 26. The sources describe the element itself, so the recipe is a single component. Iron ore is refined into iron and steel at blast furnaces and basic oxygen furnaces (USGS).
parts:
- name: Iron
symbol: Fe
atoms: 1
atomic_weight: 55.845
role: The whole element. It has a body-centered cubic crystal structure and is ferromagnetic below its Curie temperature of 1043 K.
risk_groups:
- title: For people
level: 0
verdict: 'Solid iron: no hazard in sources read'
lead: The solid metal is not described as hazardous in the sources read. PubChem's summary is mostly 'does not meet criteria', but the classified reports and the powder sheet show a flammable-solid hazard.
points:
- label: Solid metal
line: PubChem reports that 74.1% (4458 of 6013) of reports say the substance does not meet GHS hazard criteria.
- label: Powder
line: A Fujifilm Wako sheet for iron powder gives H228 Flammable solid with signal word Warning.
- title: If iron is a fine powder
lead: Fine iron can ignite. Keep it away from strong oxidizing agents and use local exhaust indoors.
verdict: Powder is a flammable solid (H228)
points:
- label: Classification
line: H228 Flammable solid appears in the powder sheet and in 15.5% of PubChem reports. H251 Self-heating appears in 21.2% of PubChem reports.
why: Iron (Fe) is a ferromagnetic metal. Its density is 7.874 g/cm3 and its melting point is 1538 °C, per periodictable.com. Iron is used for magnetic shielding and for soft magnetic parts, and a supplier sells high-purity soft ingot iron for those uses. The CERN review that describes soft magnetic materials warns that very pure iron is not suited to alternating-current use, so the purity and duty of the part decide whether iron is a good fit.
uses:
- where: Magnetic shielding
line: Goodfellow sells ARMCO soft ingot iron foil at 99.8% purity and describes it as widely used in magnetic shielding, flux return paths, transformer laminations and low-temperature magnetic measurements. These are vendor claims, not test data.
- where: Soft magnetic cores and shields
line: A CERN review lists transformer cores and shielding of magnetic fields among the uses of soft ferromagnetic materials. The same review says very pure iron is unsuitable for ac applications.
can_do:
- label: Mass estimate
benchmark: density
line: Give a density of 7.874 g/cm3 for mass estimates of solid pieces (periodictable.com).
- label: Magnetic state
benchmark: curie_temperature
value: 1043 K
line: Stay below its Curie temperature of 1043 K to remain ferromagnetic (periodictable.com).
- label: Heat conduction
benchmark: thermal_conductivity
line: Conduct heat at 79 W/(m K) on periodictable.com or 80 W m-1 K-1 on WebElements; the two pages differ by one unit.
- label: Magnetic saturation
benchmark: saturation_magnetization
value: 2.15 T
line: Carry a saturation magnetization of 2.15 T; the CERN review says purity does not strongly change it.
compare: The two reference pages give one value per property for iron, and where they differ both are kept. Thermal conductivity reads 79 W/(m K) on periodictable.com and 80 W m-1 K-1 on WebElements. The magnetic figures and the Curie temperature of 1043 K come from periodictable.com and the CERN review, which gives 2.15 T for saturation magnetization. No comparison with other metals is made here, because the sources for other metals are not part of this profile.
compare_rows:
- label: Density
benchmark: density
- label: Melting point
benchmark: melting_point
- label: Stiffness
benchmark: elastic_modulus
handling:
- Keep powder away from strong oxidizing agents and from acidic and alkaline substances (Fujifilm sheet).
- Use a local exhaust system indoors when handling powder (Fujifilm sheet).
- Very pure iron is unsuitable for alternating-current use (CERN review), so check the duty before choosing it.
good_for:
- Magnetic shielding stock where purity and soft magnetic behaviour matter (vendor description).
- 'Reference data for the element: density, melting point, elastic constants and Curie temperature from two reference pages.'
watch_out:
- Very pure iron is unsuitable for alternating-current applications (CERN review).
- Iron powder is a flammable solid (H228) in the Fujifilm sheet and in some PubChem reports.
- The humidity data here come from an irradiation test, not from atmospheric rusting, which was not found in an open source.
verdict: Iron is well documented as an element, with density, melting point and elastic constants from two reference pages. Its magnetic use depends on purity and on keeping it out of alternating-current duty.
References
Every number above carries a reference number. Click one to see the source and where in it the value comes from.
| # | Source | Type | Year | Used for |
|---|---|---|---|---|
| Iron: 26Fe, physical properties (WebElements) | web | 2026 | 2 values | |
| Iron (Fe, element 26): data (Periodic Table, periodictable.com) | database | 2026 | 17 values | |
| Mineral Commodity Summaries 2026, Iron Ore | report | 2026 | 1 value | |
| PubChem compound record, Iron (CID 23925), GHS classification | database | 2026 | 1 value | |
| Physics and measurements of magnetic materials (S. Sgobba, CERN) | paper | 2011 | 3 values | |
| ARMCO soft ingot iron foil (Goodfellow product page) | web | 2026 | 1 value | |
| Safety data sheet, Iron, Powder (Fujifilm Wako Pure Chemical, revision 6.02) | datasheet | 2023 | 3 values | |
| Use ion beam techniques to study the coupling between air and its relative humidity on iron corrosion under irradiation | paper | 2005 | 1 value |