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.