Osmium

CAS 7440-04-2OsMetal & Ceramic Science

Osmium (CAS: 7440-04-2, Formula: Os) is a dense, hard, bluish-white transition metal with a molecular weight of 190.23 g/mol. As a platinum group metal, it exhibits excellent corrosion resistance and high melting and boiling points. Osmium is primarily utilised in applications requiring extreme hardness and durability, such as electrical contacts and specialised alloys.

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Osmium (Os) — chemical element, CAS 7440-04-2; Materials Science, fine chemical supplied by Tech Serve Solutions

Materials ScienceMetal and Ceramic ScienceMetalsOsmium

01 /Applications

Electrical Contacts

Osmium's high melting point and hardness make it suitable for durable electrical contacts, particularly in demanding applications where wear resistance is critical.

Hardened Alloys

It is often alloyed with other platinum group metals or with iridium to create exceptionally hard and corrosion-resistant materials for specialised industrial uses.

Catalysis

While less common than other platinum group metals, osmium compounds can serve as catalysts in specific organic synthesis reactions.

02 /Properties

Molecular weight	190.23
Empirical formula	Os
Assay	99.8%
Form	powder
Boiling point	5027 °C(lit.)
Density	22.61 g/cm3(lit.)
Melting point	3045 °C(lit.)

03 /Safety & handling

GHS hazard pictogram: Flammable (GHS02) — Flammable

GHS hazard pictogram: Corrosive (GHS05) — Corrosive

GHS hazard pictogram: Harmful / irritant (GHS07) — Harmful / irritant

Danger

Hazard statements

H228Flammable solid
H315Causes skin irritation
H318Causes serious eye damage
H335May cause respiratory irritation

Precautionary statements

P210Keep away from heat, sparks and open flames. No smoking
P261Avoid breathing dust, fume, gas or vapours
P280Wear protective gloves, clothing and eye/face protection
P305IF IN EYES

Protective equipment	dust mask type N95 (US), Eyeshields, full-face particle respirator type N100 (US), Gloves, respirator cartridge type N100 (US), type P1 (EN143) respirator filter, type P3 (EN 143) respirator cartridges
Transport (UN / ADR)	UN 3089 4.1 / PGII
Water hazard class (WGK, DE)	nwg
Hazard codes (EU)	F,Xi
Risk statements (R)	11-37/38-41
Safety statements (S)	16-26-36/37/39

Hazard information is provided for guidance. Always consult the product Safety Data Sheet (SDS), available on request, before handling.

04 /Identifiers & registry

CAS number

7440-04-2

MDL number

MFCD00011147

PubChem substance

24855959

05 /Additional specifications

Resistivity	8.12 μΩ-cm, 20°C

06 /Quality & supply

Documentation

Every batch ships with a Certificate of Analysis covering assay, identity and purity; the grade is confirmed against your enquiry. Safety Data Sheets and technical data sheets are available on request.

Supply & logistics

Samples for technical evaluation; bulk MOQ by grade and packaging. In-stock material ships in 7–10 working days, worldwide, with full export documentation.

07 /Frequently asked questions

What is Osmium (CAS 7440-04-2) used for?

Osmium is primarily used in applications requiring extreme hardness and durability, such as in the manufacturing of electrical contacts and specialised, corrosion-resistant alloys.

What are the CAS number and formula for Osmium?

The CAS number for Osmium is 7440-04-2, and its chemical formula is Os.

What grade and purity does Tech Serve Solutions supply for Osmium?

Tech Serve Solutions supplies Osmium with an assay of 99.8%. We do not represent this product as USP, BP, or EP grade.

How should Osmium powder be handled safely?

Osmium powder is flammable and can cause skin irritation, serious eye damage, and respiratory irritation. Handle with appropriate personal protective equipment, including a dust mask (N95), eyeshields, gloves, and a respirator with suitable cartridges. Ensure good ventilation and avoid dust formation. Keep away from ignition sources.