{ "spore": "profile", "id": "tungsten", "spore_version": "0.2", "family": "refractory-metals", "name": "Tungsten", "abbreviation": "W", "role": "refractory metal", "category": "metals", "type": "refractory-metals", "summary": "Tungsten is a steel-grey metal with the highest melting point of any metal, about 3,422 degC (ITIA). Its density of about 19.3 g/cm3 puts it among the heaviest metals, and its stiffness and hardness are high. Tungsten oxidises in air at high temperature and must be protected there. Most of the world's tungsten is mined in China, and in the United States about 60% of consumption goes into cemented carbide cutting and wear parts. In spaceflight-related work it has been used as rocket nozzle inserts and as a gamma-ray shield near nuclear reactors.\n", "best_for": "Very high temperature parts, dense counterweights and gamma shielding where weight per unit of shielding matters more than cost", "weakest_at": "Brittle and hard to form or machine; oxidises in air when hot, so it needs protection above room temperature", "identity": { "formula": "W", "cas": "7440-33-7", "crystal_system": "body-centred cubic (bcc)", "designations": [], "source": "we-main", "where": "Crystal structure line on the WebElements main page; CAS number from PubChem CID 23964" }, "tags": { "environments": [], "stresses": [], "applications": [ "propulsion-and-tanks", "radiation-shielding", "mechanisms" ] }, "properties": [ { "benchmark": "density", "value": 19250, "bound": "exact", "unit": "kg/m3", "scope": "material", "conditions": { "basis": "no temperature stated on the page" }, "method": "Physical properties table, Density of solid, as printed", "status": "ground", "source": "we-physics", "where": "Density properties section (WebElements tungsten physics page)", "source_detail": { "title": "WebElements: Tungsten, physical properties", "id": "WebElements, tungsten physics page", "url": "https://www.webelements.com/tungsten/physics.html", "kind": "database", "license": "WebElements terms of use (cited, not reproduced)" } }, { "benchmark": "density", "value": 19.25, "bound": "exact", "unit": "g/cm3", "scope": "material", "conditions": { "basis": "value quoted in running text, no temperature stated" }, "method": "Stated in the ITIA properties text", "status": "ground", "source": "itia", "where": "Properties and intermediates page, first paragraph on tungsten properties", "source_detail": { "title": "ITIA: Tungsten properties and intermediates", "id": "International Tungsten Industry Association, properties page", "url": "https://www.itia.info/properties-intermediates/", "kind": "web", "license": "ITIA website (cited, not reproduced)" } }, { "benchmark": "density", "value": 19.3, "bound": "exact", "unit": "g/cm3", "scope": "material", "conditions": { "basis": "PAC Chemical Database value at 25 degC as printed" }, "method": "Value listed in the PubChem compound record (PAC Chemical Database entry)", "status": "ground", "source": "pubchem-w", "where": "Density, PAC Chemical Database entry (ref 46)", "source_detail": { "title": "PubChem: Tungsten (CID 23964)", "id": "PubChem compound record 23964", "url": "https://pubchem.ncbi.nlm.nih.gov/compound/Tungsten", "kind": "database", "license": "Public domain record (cited, not reproduced)" } }, { "benchmark": "melting_point", "value": 3695, "bound": "exact", "unit": "K", "scope": "material", "conditions": { "basis": "printed as 3695 K [3422 degC (6192 degF)]" }, "method": "Key properties table on the WebElements main page", "status": "ground", "source": "we-main", "where": "Key properties, Melting point row", "source_detail": { "title": "WebElements: Tungsten, key properties and description", "id": "WebElements, tungsten main page", "url": "https://www.webelements.com/tungsten/", "kind": "database", "license": "WebElements terms of use (cited, not reproduced)" } }, { "benchmark": "melting_point", "value": 3422, "bound": "exact", "unit": "degC", "scope": "material", "conditions": { "basis": "ITIA gives 3,422 +/- 15 degC; the value here is the central figure" }, "method": "Stated in the ITIA properties text", "status": "ground", "source": "itia", "where": "Properties and intermediates page, first paragraph on tungsten properties", "source_detail": { "title": "ITIA: Tungsten properties and intermediates", "id": "International Tungsten Industry Association, properties page", "url": "https://www.itia.info/properties-intermediates/", "kind": "web", "license": "ITIA website (cited, not reproduced)" } }, { "benchmark": "boiling_point", "value": 5828, "bound": "exact", "unit": "K", "scope": "material", "conditions": { "basis": "printed as 5828 K [5555 degC (10031 degF)]" }, "method": "Key properties table on the WebElements main page", "status": "ground", "source": "we-main", "where": "Key properties, Boiling point row", "source_detail": { "title": "WebElements: Tungsten, key properties and description", "id": "WebElements, tungsten main page", "url": "https://www.webelements.com/tungsten/", "kind": "database", "license": "WebElements terms of use (cited, not reproduced)" } }, { "benchmark": "thermal_conductivity", "value": 174, "bound": "exact", "unit": "W m-1 K-1", "scope": "material", "conditions": { "basis": "no temperature stated on the page" }, "method": "Physical properties table as printed", "status": "ground", "source": "we-physics", "where": "Thermal conductivity line (WebElements tungsten physics page)", "source_detail": { "title": "WebElements: Tungsten, physical properties", "id": "WebElements, tungsten physics page", "url": "https://www.webelements.com/tungsten/physics.html", "kind": "database", "license": "WebElements terms of use (cited, not reproduced)" } }, { "benchmark": "cte", "value": 0.0000045, "bound": "exact", "unit": "K-1", "scope": "material", "conditions": { "basis": "coefficient of linear thermal expansion, no temperature stated on the page" }, "method": "Physical properties table, printed as 4.5 x 10-6 K-1", "status": "ground", "source": "we-physics", "where": "Coefficient of linear thermal expansion line (WebElements tungsten physics page)", "source_detail": { "title": "WebElements: Tungsten, physical properties", "id": "WebElements, tungsten physics page", "url": "https://www.webelements.com/tungsten/physics.html", "kind": "database", "license": "WebElements terms of use (cited, not reproduced)" } }, { "benchmark": "elastic_modulus", "value": 411, "bound": "exact", "unit": "GPa", "scope": "material", "conditions": { "basis": "no temperature stated on the page" }, "method": "Young's modulus as printed in the physical properties section", "status": "ground", "source": "we-physics", "where": "Density and elastic properties section, Young's modulus line", "source_detail": { "title": "WebElements: Tungsten, physical properties", "id": "WebElements, tungsten physics page", "url": "https://www.webelements.com/tungsten/physics.html", "kind": "database", "license": "WebElements terms of use (cited, not reproduced)" } }, { "benchmark": "shear_modulus", "value": 161, "bound": "exact", "unit": "GPa", "scope": "material", "conditions": { "basis": "no temperature stated on the page" }, "method": "Printed as rigidity modulus on the WebElements page", "status": "ground", "source": "we-physics", "where": "Rigidity modulus line", "source_detail": { "title": "WebElements: Tungsten, physical properties", "id": "WebElements, tungsten physics page", "url": "https://www.webelements.com/tungsten/physics.html", "kind": "database", "license": "WebElements terms of use (cited, not reproduced)" } }, { "benchmark": "bulk_modulus", "value": 310, "bound": "exact", "unit": "GPa", "scope": "material", "conditions": { "basis": "no temperature stated on the page" }, "method": "Printed as bulk modulus on the WebElements page", "status": "ground", "source": "we-physics", "where": "Bulk modulus line", "source_detail": { "title": "WebElements: Tungsten, physical properties", "id": "WebElements, tungsten physics page", "url": "https://www.webelements.com/tungsten/physics.html", "kind": "database", "license": "WebElements terms of use (cited, not reproduced)" } }, { "benchmark": "poissons_ratio", "value": 0.28, "bound": "exact", "unit": "(no units)", "scope": "material", "conditions": { "basis": "no temperature stated on the page" }, "method": "Printed on the WebElements page", "status": "ground", "source": "we-physics", "where": "Poisson's ratio line", "source_detail": { "title": "WebElements: Tungsten, physical properties", "id": "WebElements, tungsten physics page", "url": "https://www.webelements.com/tungsten/physics.html", "kind": "database", "license": "WebElements terms of use (cited, not reproduced)" } }, { "benchmark": "electrical_resistivity", "value": 5.4e-8, "bound": "exact", "unit": "ohm m", "scope": "material", "conditions": { "basis": "no temperature stated on the page" }, "method": "Printed as 5.4 x 10-8 ohm m on the WebElements page", "status": "ground", "source": "we-physics", "where": "Electrical resistivity line", "source_detail": { "title": "WebElements: Tungsten, physical properties", "id": "WebElements, tungsten physics page", "url": "https://www.webelements.com/tungsten/physics.html", "kind": "database", "license": "WebElements terms of use (cited, not reproduced)" } }, { "benchmark": "vickers_hardness", "value": 3430, "bound": "exact", "unit": "MN m-2", "scope": "material", "conditions": { "basis": "no test conditions stated on the page" }, "method": "Printed as Vickers hardness on the WebElements page (not a canonical property name; see gaps)", "status": "ground", "source": "we-physics", "where": "Hardnesses section, Vickers hardness line", "source_detail": { "title": "WebElements: Tungsten, physical properties", "id": "WebElements, tungsten physics page", "url": "https://www.webelements.com/tungsten/physics.html", "kind": "database", "license": "WebElements terms of use (cited, not reproduced)" } }, { "benchmark": "brinell_hardness", "value": 2570, "bound": "exact", "unit": "MN m-2", "scope": "material", "conditions": { "basis": "no test conditions stated on the page" }, "method": "Printed as Brinell hardness on the WebElements page (not a canonical property name; see gaps)", "status": "ground", "source": "we-physics", "where": "Hardnesses section, Brinell hardness line", "source_detail": { "title": "WebElements: Tungsten, physical properties", "id": "WebElements, tungsten physics page", "url": "https://www.webelements.com/tungsten/physics.html", "kind": "database", "license": "WebElements terms of use (cited, not reproduced)" } }, { "benchmark": "mohs_hardness", "value": 7.5, "bound": "exact", "unit": "(no units)", "scope": "material", "conditions": { "basis": "mineral hardness scale" }, "method": "Printed as mineral hardness on the WebElements page (not a canonical property name; see gaps)", "status": "ground", "source": "we-physics", "where": "Hardnesses section, Mineral hardness line", "source_detail": { "title": "WebElements: Tungsten, physical properties", "id": "WebElements, tungsten physics page", "url": "https://www.webelements.com/tungsten/physics.html", "kind": "database", "license": "WebElements terms of use (cited, not reproduced)" } }, { "benchmark": "atomic_weight", "value": 183.84, "bound": "exact", "unit": "g/mol", "scope": "material", "conditions": { "basis": "PubChem record for elemental tungsten (CID 23964) gives the molecular weight, which equals the atomic weight of W" }, "method": "Molecular Weight field of the PubChem compound record", "status": "ground", "source": "pubchem-w", "where": "Molecular Weight (PubChem property table, CID 23964)", "source_detail": { "title": "PubChem: Tungsten (CID 23964)", "id": "PubChem compound record 23964", "url": "https://pubchem.ncbi.nlm.nih.gov/compound/Tungsten", "kind": "database", "license": "Public domain record (cited, not reproduced)" } } ], "corrosion": [ { "environment": "Air at elevated temperature", "headline": "Tungsten oxidises in air and must be protected when hot.", "effect": "The WebElements description says the metal oxidises in air and must be protected at elevated temperatures. The HSDB stability entry in PubChem says it oxidises in air at elevated temperature and must be protected.", "rating": "moderate", "conditions": { "basis": "qualitative statements, no temperatures or exposure times given" }, "source": "we-main", "where": "Description paragraph (WebElements main page)" }, { "environment": "Dry air at ordinary temperature", "headline": "Stable in dry air at ordinary temperature.", "effect": "The HSDB stability entry in PubChem says tungsten is stable in dry air at ordinary temperature. It gives no humidity or exposure data.", "rating": "low", "conditions": { "basis": "qualitative HSDB statement; no humidity given" }, "source": "pubchem-w", "where": "Stability/Shelf Life (HSDB, via PubChem)" }, { "environment": "Mineral acids", "headline": "Excellent corrosion resistance; attacked only slightly by most mineral acids.", "effect": "The WebElements description says tungsten has excellent corrosion resistance and is attacked only slightly by most mineral acids.", "rating": "low", "conditions": { "basis": "qualitative statement, no acid concentrations given" }, "source": "we-main", "where": "Description paragraph (WebElements main page)" }, { "environment": "Nitric, sulfuric and aqua regia; hydrofluoric plus nitric acid; molten alkali", "headline": "Very slow attack in nitric and sulfuric acid; dissolved by hydrofluoric plus nitric acid.", "effect": "The CAMEO reactivity profile in PubChem says tungsten is very slowly attacked by nitric acid, sulfuric acid and aqua regia, and dissolved by a mixture of hydrofluoric and nitric acids. It has no reaction with aqueous bases, but it is attacked rapidly by molten alkaline melts such as Na2O2 or KNO3/NaOH.", "rating": "severe", "conditions": { "basis": "qualitative CAMEO reactivity profile; no temperatures or concentrations given" }, "source": "pubchem-w", "where": "Reactivity Profile (CAMEO Chemicals, via PubChem)" } ], "risks": { "hazards": [ { "text": "PubChem's ECHA aggregate of 741 company reports lists Danger, H228 (flammable solid, 73.4% of reports) and H252 (self-heating in large quantities, 47.8%). The same record says 26.5% of reports do not meet GHS criteria.", "ghs": [ "H228", "H252" ], "source": "pubchem-w", "where": "GHS Classification, ECHA aggregated (ref 27)" }, { "text": "PubChem's NITE classification gives H320 (causes eye irritation) and H335 (may cause respiratory irritation), with the Warning signal word.", "ghs": [ "H320", "H335" ], "source": "pubchem-w", "where": "GHS Classification, NITE-CMC (ref 42)" }, { "text": "NIOSH pocket guide excerpt in PubChem: exposure by inhalation, ingestion, or skin or eye contact. Symptoms include irritation of the eyes, skin and respiratory system, diffuse pulmonary fibrosis, loss of appetite, nausea, cough and blood changes. Target organs are the eyes, skin, respiratory system and blood.", "ghs": [], "source": "pubchem-w", "where": "Health Hazards (NIOSH excerpt in CAMEO Chemicals, via PubChem)" } ], "failure_risks": [ { "mode": "Dust fire", "trigger": "Dust from grinding that accumulates and meets an ignition source", "consequence": "CAMEO says tungsten dust may present a moderate fire hazard if allowed to accumulate.", "severity": "moderate", "source": "pubchem-w", "where": "Physical Description (CAMEO Chemicals, via PubChem)" }, { "mode": "Oxidation at elevated temperature", "trigger": "Hot tungsten exposed to air without protection", "consequence": "The metal oxidises and must be protected at elevated temperatures.", "severity": "moderate", "source": "we-main", "where": "Description paragraph (WebElements main page)" } ], "side_effects": [], "handling": [ { "text": "Keep it protected from air when hot. HSDB says it is stable in dry air at ordinary temperature.", "source": "pubchem-w", "where": "Stability/Shelf Life (HSDB, via PubChem)" }, { "text": "Avoid letting dust from grinding accumulate, and keep ignition sources away from it (CAMEO).", "source": "pubchem-w", "where": "Physical Description (CAMEO Chemicals, via PubChem)" } ], "mitigations": [] }, "uses": [ { "application": "propulsion-and-tanks", "device": "Rocket nozzle throat inserts", "example": "NASA contract report on tungsten encapsulated, silver-infiltrated porous tungsten rocket nozzle inserts, with design and firing tests of the throat insert. Tungsten was chosen for its high melting point.", "source": "ntrs-nozzle", "where": "Title page and body text (NASA CR-66759, prepared under NAS 1-4722)" }, { "application": "radiation-shielding", "device": "Gamma shield near a space nuclear reactor", "example": "A 1973 NASA review recommends a tungsten alloy for gamma shield layers near the reactor, where depleted uranium fissioning would add heat and swelling. It calls tungsten the most efficient gamma attenuator on a minimum-shield-weight basis, though costly.", "source": "ntrs-shield-1973", "where": "Summary and Introduction; Tungsten heavy-metal alloys section" }, { "application": "mechanisms", "device": "Heavy-alloy counterweights and vibration damping", "example": "ITIA lists tungsten heavy alloys for ammunition, counterweights, vibration damping and radiation shielding among tungsten metal products.", "source": "itia-apps", "where": "Tungsten metal products section (ITIA applications page)" }, { "application": "mechanisms", "device": "Phone vibration motors (mobile vibrators)", "example": "Wikipedia says tungsten is used in vibration motors because its high density, hardness and wear resistance withstand high-speed rotation. Only this secondary source was found for this use.", "source": "wiki-tungsten", "where": "Applications section (Wikipedia tungsten article)" } ], "supply": [ { "subject": "Tungsten (mine production shares computed from USGS 2025 tonnes of contained W, world total 85,000 t)", "abundance": "Crustal abundance not stated in the USGS tungsten summary (see gaps).", "producers": [ { "country": "China", "share_percent": 78.8, "year": 2025 }, { "country": "Vietnam", "share_percent": 3.5, "year": 2025 }, { "country": "Kazakhstan", "share_percent": 2.8, "year": 2025 }, { "country": "Russia", "share_percent": 2.4, "year": 2025 }, { "country": "Bolivia", "share_percent": 2, "year": 2025 }, { "country": "Australia", "share_percent": 1.2, "year": 2025 } ], "critical_lists": [], "substitutes": [], "source": "usgs-mcs-2026" }, { "subject": "Reserves and trade (USGS 2026 summary)", "abundance": "China holds 2,500,000 t of W reserves of more than 4,700,000 t world total (about 53%, computed). US mine production is zero; the US is more than 50% net import reliant. Import sources 2021 to 2024: China 26%, Germany 14%, Bolivia 8%, Vietnam 8%. China implemented new export controls on selected tungsten items in February 2025. Rotterdam APT prices rose from $331 to $675 per metric ton unit during 2025.", "producers": [], "critical_lists": [], "substitutes": [], "source": "usgs-mcs-2026" } ], "media": [], "documents": [ { "title": "USGS Mineral Commodity Summaries 2026: Tungsten", "type": "report", "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-tungsten.pdf", "year": 2026 }, { "title": "WebElements: Tungsten, physical properties", "type": "database", "url": "https://www.webelements.com/tungsten/physics.html" }, { "title": "WebElements: Tungsten, key properties", "type": "database", "url": "https://www.webelements.com/tungsten/" }, { "title": "ITIA: Tungsten properties and intermediates", "type": "datasheet", "url": "https://www.itia.info/properties-intermediates/" }, { "title": "PubChem: Tungsten (CID 23964), property, GHS and safety records", "type": "database", "url": "https://pubchem.ncbi.nlm.nih.gov/compound/Tungsten" }, { "title": "NASA: Shield materials recommended for space power nuclear reactors (July 1973)", "type": "report", "url": "https://ntrs.nasa.gov/citations/19730018853", "year": 1973 }, { "title": "NASA CR-66759: Design, fabrication and evaluation of tungsten encapsulated silver infiltrated porous tungsten rocket nozzle inserts", "type": "report", "url": "https://ntrs.nasa.gov/citations/19690016813" } ], "gaps": [ "Numeric gamma-ray attenuation (mass attenuation or half-value layer) for tungsten was not read. The NIST XCOM pages returned errors in this run, so the shielding claim rests on a qualitative 1973 NASA review.", "NIST atomic weight table did not show tungsten in the page we could open; the atomic weight 183.84 comes from PubChem.", "The Plansee tungsten datasheet returned Access Denied; ITIA and WebElements were used for the physical properties instead.", "Phone vibration motor use is supported only by Wikipedia, and the brief limits Wikipedia to composition and history. Treat that use as unverified.", "Vickers hardness, Brinell hardness and Mohs hardness are not canonical property names and were entered as snake_case names.", "The WebElements physics page gives no test temperature for density, thermal conductivity, CTE or modulus.", "Crustal abundance of tungsten was not found in the USGS summary, and no supply source for crustal abundance was read.", "Whether tungsten is on the USGS 2025 critical minerals list or the EU critical raw materials list was not stated in the USGS tungsten summary and was not checked in another source.", "Secondary (recycled) tungsten quantity for 2025 is withheld in the USGS summary, so recycling share is not given.", "NASA CR-66759 publication year was not read on the cover; the firing tests it describes are dated 1965 to 1968 in the text.", "Corrosion data are qualitative; no tungsten corrosion rate in oxidising air or acid was read." ], "story": { "why": "Tungsten (W) is a refractory metal. It melts at about 3,422 degC (ITIA), the highest of any metal. At that temperature most other engineering metals, such as iron, aluminium, copper and titanium, have already vaporised (ITIA). It is also very dense, about 19.3 g/cm3, and stiff, with a Young's modulus of 411 GPa. Those properties explain its uses in rocket nozzle inserts, gamma shields, counterweights and hard alloys. The price is brittleness, difficult forming and a need for protection from air when hot.", "uses": [ { "where": "Rocket nozzles", "line": "A NASA contract report describes tungsten encapsulated, silver-infiltrated porous tungsten nozzle inserts and their firing tests. Tungsten's high melting point is the reason for its use in the throat." }, { "where": "Gamma shielding near a reactor", "line": "A 1973 NASA review recommends a tungsten alloy for the gamma shield near a space reactor. It calls tungsten the most efficient gamma attenuator on a minimum-weight basis, though costly." }, { "where": "Vibration motors in phones", "line": "Wikipedia says tungsten is used in the vibration motors that give phones their tactile alerts, because its density and wear resistance suit high-speed rotation. We did not find a manufacturer or standards source for this use." }, { "where": "Cutting tools and carbides", "line": "The USGS reports that about 60% of US tungsten consumption goes into cemented carbide parts for cutting and wear-resistant applications." } ], "can_do": [ { "label": "Melting point", "line": "ITIA gives 3,422 +/- 15 degC for the melting point. WebElements gives 3695 K, which is the same temperature in kelvin.", "benchmark": "melting_point", "scope": "material", "value": "3422 degC" }, { "label": "Density", "line": "Density is 19.25 g/cm3 in ITIA and 19250 kg/m3 in WebElements, so tungsten is among the heaviest metals.", "benchmark": "density", "scope": "material", "value": "19.25 g/cm3" }, { "label": "Stiffness", "line": "WebElements gives a Young's modulus of 411 GPa and a shear modulus of 161 GPa.", "benchmark": "elastic_modulus", "scope": "material", "value": "411 GPa" }, { "label": "Thermal conductivity", "line": "WebElements gives 174 W m-1 K-1 at a temperature it does not state.", "benchmark": "thermal_conductivity", "scope": "material", "value": "174 W m-1 K-1" } ], "compare": "Tungsten sits at the top of the metals in melting point, at 3,422 degC, and it is one of the densest, at about 19.3 g/cm3. Its linear thermal expansion coefficient is 4.5 x 10-6 K-1 as printed by WebElements. The table compares its melting point, density and thermal conductivity as printed in the sources.", "compare_rows": [ { "label": "Melting point", "benchmark": "melting_point", "scope": "material" }, { "label": "Density", "benchmark": "density", "scope": "material" }, { "label": "Thermal conductivity", "benchmark": "thermal_conductivity", "scope": "material" } ], "handling": [ "Protect it from air when hot. WebElements says it oxidises and must be protected at elevated temperatures.", "Keep grinding dust from building up, since CAMEO notes a moderate fire hazard.", "Treat it as an eye and airway irritant. NITE classifies it with H320 and H335, and the NIOSH excerpt lists the same organs." ], "good_for": [ "Parts used at very high temperature. WebElements says tungsten has the highest tensile strength of all metals in that range.", "Dense counterweights and gamma shields, where mass per unit of shielding matters more than cost." ], "watch_out": [ "Brittle and hard to form. The ITIA says that impurities give it hardness and brittleness, which is why heavy alloys are used for big parts.", "Oxidises in air when hot, and dust from grinding can be a fire hazard.", "Supply is concentrated. China produced about 78.8% of 2025 mine output (USGS, computed), and export controls were added in February 2025." ], "verdict": "Tungsten is the choice when temperature and density matter more than weight or cost. Its melting point and density are well documented; its hardness and gamma attenuation numbers still need an open source before it is used in a design.", "recipe": { "line": "Elemental tungsten is pure W, a body-centred cubic metal with one tungsten atom per formula unit and an atomic weight of 183.84 (PubChem). Tungsten is also the basis of tungsten carbide, tungsten heavy alloys and the oxides used to make the metal powder (ITIA).", "parts": [ { "name": "Tungsten", "symbol": "W", "role": "The whole composition. Pure tungsten is a single element; the body-centred cubic crystal is what gives it its high melting point and stiffness.", "atoms": 1, "atomic_weight": 183.84 } ] }, "risk_groups": [ { "title": "For people", "lead": "The metal and its powder carry different notifications in PubChem, and the health data are limited.", "points": [ { "label": "The powder", "line": "PubChem's aggregated notifications list flammable solid (H228) and self-heating (H252) for 73.4% and 47.8% of 741 company reports. The same record says 26.5% of reports do not meet GHS criteria." }, { "label": "Eyes and breathing", "line": "NITE classifies it with H320 (eye irritation) and H335 (respiratory irritation). The NIOSH excerpt lists irritation of the eyes, skin and airways, and in some cases diffuse pulmonary fibrosis." }, { "label": "Dust", "line": "CAMEO says tungsten dust from grinding may present a moderate fire hazard if it accumulates near an ignition source." } ], "level": 0, "verdict": "Hazard classes vary by form" }, { "title": "At high temperature", "lead": "The main hazard in use is oxidation, not toxicity.", "points": [ { "label": "In air", "line": "WebElements says tungsten oxidises in air and must be protected at elevated temperatures. HSDB says it is stable in dry air at ordinary temperature." } ] } ] }, "updated": "2026-10-19", "review": { "status": "draft", "method": "assistant", "checked_values": 17, "unreachable": 2, "caveats": 3, "note": "Read by an AI assistant on 2026-10-19: 17 property values read from WebElements, ITIA and PubChem. Plansee datasheet returned Access Denied and NIST XCOM returned errors; numeric attenuation is missing." }, "sources": { "we-physics": { "title": "WebElements: Tungsten, physical properties", "id": "WebElements, tungsten physics page", "url": "https://www.webelements.com/tungsten/physics.html", "kind": "database", "license": "WebElements terms of use (cited, not reproduced)" }, "we-main": { "title": "WebElements: Tungsten, key properties and description", "id": "WebElements, tungsten main page", "url": "https://www.webelements.com/tungsten/", "kind": "database", "license": "WebElements terms of use (cited, not reproduced)" }, "itia": { "title": "ITIA: Tungsten properties and intermediates", "id": "International Tungsten Industry Association, properties page", "url": "https://www.itia.info/properties-intermediates/", "kind": "web", "license": "ITIA website (cited, not reproduced)" }, "itia-apps": { "title": "ITIA: Tungsten applications and markets", "id": "International Tungsten Industry Association, applications page", "url": "https://www.itia.info/applications-markets/", "kind": "web", "license": "ITIA website (cited, not reproduced)" }, "pubchem-w": { "title": "PubChem: Tungsten (CID 23964)", "id": "PubChem compound record 23964", "url": "https://pubchem.ncbi.nlm.nih.gov/compound/Tungsten", "kind": "database", "license": "Public domain record (cited, not reproduced)" }, "usgs-mcs-2026": { "title": "USGS Mineral Commodity Summaries 2026: Tungsten", "id": "USGS MCS 2026, tungsten", "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-tungsten.pdf", "year": 2026, "kind": "report", "license": "US government work (public domain)" }, "ntrs-shield-1973": { "title": "Shield materials recommended for space power nuclear reactors", "id": "NASA NTRS 19730018853, July 1973", "url": "https://ntrs.nasa.gov/citations/19730018853", "year": 1973, "kind": "report", "license": "NASA NTRS (public domain, cited)" }, "ntrs-nozzle": { "title": "Design, fabrication and evaluation of tungsten encapsulated silver infiltrated porous tungsten rocket nozzle inserts (NASA CR-66759)", "id": "NASA NTRS 19690016813, NASA CR-66759", "url": "https://ntrs.nasa.gov/citations/19690016813", "kind": "report", "license": "NASA NTRS (public domain, cited)" }, "wiki-tungsten": { "title": "Wikipedia: Tungsten", "id": "Wikipedia, Tungsten article", "url": "https://en.wikipedia.org/wiki/Tungsten", "kind": "web", "license": "CC BY-SA 4.0 (cited, not reproduced)" } }, "license": "CC-BY-4.0", "url": "https://spacemushroom.com/profiles/tungsten/" }