Walter WEP10C cermet grade indexable inserts are made with the MP4 medium machining geometry. The grade features a wear-resistant fine grained cermet substrate with a nickel/cobalt binder. Users can expect to double the tool life in comparison to carbide because of the wear-resistant, thermally conductive cermet substrate with a PVD TiCN/TiAlN coating. TiCN resists crater wear while TiAlN resists flank wear.

The recommended machining parameters are from 0.003" to 0.014" (0.08mm to 0.35mm) for the feed rate (f) and 0.016" to 0.138" (0.4mm to 3.5mm) for the cutting depth (ap).

The MP4 geometry is a universal geometry for medium machining applications in steel and cast iron (ISO P and K materials groups). A secondary application is stainless steel (ISO M material group). The straight cutting edge makes it an ideal geometry for boring and step boring applications.

With the positive rake chip breaker angles of 7° and 12° and an 18° second step, the geometry helps in reducing vibrations when turning and acts very effectively in aggressive chip breaking. The MP4 geometry – especially when combined with the WEP10C cermet grade – is designed with a specific hone that imparts a high-quality shiny surface finish. The geometry is also effective for finishing with continuous and slightly interrupted cuts.

The combination of the MP4 geometry and the WEP10C cermet grade proves highly effective when machining outer or internal diameters where a high dimensional accuracy is required over a long period of time (less tool compensation adjustments required over a long period of time). Cermet inserts also provide a significant cost-saving advantage due to their lower price than corresponding carbide inserts.