Copper-Tungsten Class 11

Class 11 Copper Tungsten contains 25% copper and 75% tungsten. With a higher tungsten content than Class 10, it delivers greater hardness and wear resistance while retaining good thermal and electrical conductivity. Class 11 is the standard choice for applications that require moderate to high electrode pressure. Common uses include projection welding electrodes, flash and butt welding dies, light upsetting and seam welding bushings, and spot welding low-conductivity steels. It is also widely specified for chip carriers, substrates, flanges, and frames in power semiconductor devices.

RWMA Class 11 · Trade designation 10W3

COPPER TUNGSTEN CLASS 11 (10W3)

Class 11 is harder and more wear-resistant than Class 10 and is recommended as facing inserts for flash and butt welding dies, and as a general-purpose projection welding electrode material. It is also used for seam welder bearing inserts and as a facing for electro-forming and electro-forging operations, including stainless steel applications.

How Class 11 Compares to Class 10

Class 10 and Class 11 are the two most commonly specified copper-tungsten grades, and the choice between them comes down to a tradeoff between conductivity and hardness.

Specify Class 10 when conductivity, malleability, and machinability are the priorities. Specify Class 11 when electrode pressure, hardness, and wear resistance are limiting electrode life — particularly for projection welding and die facing applications where the electrode geometry must hold up under repeated mechanical load.

Machinability

Class 11 can be machined with standard carbide tooling, though the higher tungsten content makes it harder and slower to cut than Class 10. Turning, milling, and drilling are routine for finished electrode geometries; grinding is recommended for tight-tolerance surfaces. NSRW produces custom-machined Class 11 electrodes, inserts, and die facings to print.