Tungsten , 99.9%metalsbasis,50nm , 7440-33-7

Synonym(s):
Tungsten;W;W 00BO35;W 00BO55;W 00BO65

CAS NO.：7440-33-7

Empirical Formula: W

Molecular Weight: 183.84

MDL number: MFCD00011461

EINECS: 231-143-9

PRODUCT Properties

• Melting point: 3410 °C (lit.)
• Boiling point: 5660 °C (lit.)
• Density: 19.3 g/mL at 25 °C (lit.)
• bulk density: 4000kg/m3
• vapor pressure: 0Pa at 3000℃
• Flash point: -23 °C
• storage temp.: no restrictions.
• form: wire
• color: Silver-gray
• Specific Gravity: 19.3
• Flame Color: Green
• Resistivity: 4.9 μΩ-cm, 20°C
• Water Solubility: insoluble
• Merck: 13,9884
• Exposure limits: ACGIH: TWA 2 ppm; STEL 4 ppm; OSHA: TWA 2 ppm(5 mg/m3); NIOSH: IDLH 25 ppm; TWA 2 ppm(5 mg/m3); STEL 4 ppm(10 mg/m3)
• Stability: Stable. Dust is flammable, though not likely to present a hazard if normal good practice is used.
• Poissons Ratio: 0.28
• Hardness, Brinell: 444, Converted from Vickers for 3000 kg load/10 mm ball Brinell test. Drawn and annealed.
• Hardness, Knoop: 505, Estimated from Vickers.
• Hardness, Rockwell A: 74, Converted from Vickers. Drawn and annealed.
• Hardness, Vickers: 480, Drawn and annealed.
• Shear Modulus: 156 GPa, Calculated
• Hardness, Rockwell C: 47, Converted from Vickers. Drawn and annealed.
• Modulus of Elasticity: 400 GPa
• CAS DataBase Reference: 7440-33-7(CAS DataBase Reference)
• NIST Chemistry Reference: Tungsten(7440-33-7)
• EPA Substance Registry System: Tungsten (7440-33-7)

Description and Uses

Tungsten was recognized as a distinct element in 1779 by Peter Woulfe, but not isolated until 1783, by Jose and Fausto d’Elhuyar. The average tungsten concentration in the earth’s crust is ~0.006%. Tungsten occurs naturally as tungstate, mainly in compounds such as wolframites and scheelites.

Tungsten, also known as wolfram, occurs as wolframite (FeWO4). It can be found in the earth’s crust but not in its pure metal form. It combines with other chemicals and compounds within the rocky earth’s crust. It is a transitional hard metal with physicochemical properties and can also be manufactured commercially (Lassner and Schnubert, 1999; Gbaruko and Igwe, 2007; Stefaniak, 2010; Strigul et al., 2010).
Tungsten is most commonly used to increase the hardness of steel. It is available commercially in the form of powder, single crystal, and ultrapure granule grades. It is also used in the manufacturing of alloys, light filaments, and X-ray tubes. A recent use for tungsten is as a lead substitute during the manufacturing of ammunition and sporting good products. Another recent commercial use for tungsten is in the production of wedding bands. It is also used as a catalyst in chemical reactions (Lassner and Schnubert, 1999; Gbaruko and Igwe, 2007; Stefaniak, 2010; Strigul et al., 2010).
To increase hardness, toughness, elasticity, and tensile strength of steel; manufacture of alloys; manufacture of filaments for incandescent lamps and in electron tubes; in contact points for automotive, telegraph, radio and television apparatus; in phonograph needles. Tungsten carbides (W2C, WC) used in rock drills, metal-cutting tools, wire-drawing dies. WC used as catalyst instead of platinum: Bennett et al., Science 184, 563 (1974).

Safety

• Symbol(GHS): GHS02
• Signal word: Danger
• Hazard statements: H228-H252
• Precautionary statements: P210-P235-P240-P241-P280-P370+P378
• Hazard Codes: F,Xi,N,Xn
• Risk Statements: 11-36/38-67-65-62-51/53-48/20-38
• Safety Statements: 6-26-36-62-61-36/37-16
• RIDADR: UN 3089 4.1/PG 2
• OEB: B
• OEL: TWA: 5 mg/m3, STEL: 10 mg/m3 [*Note: The REL also applies to other insoluble tungsten compounds (as W).]
• WGK Germany: -
• RTECS: YO7175000
• TSCA: Yes
• HazardClass: 4.1
• PackingGroup: III
• HS Code: 81011000
• Hazardous Substances Data: 7440-33-7(Hazardous Substances Data)