Grade THMTTMTTRTTI15 WIDIA™ Inserts Grades and Grade Descriptions Coatings provide high-speed P Steel capability and are engineered M Stainless Steel for finishing to heavy roughing. K Cast Iron N Non-Ferrous S High-Temp Alloys H Hardened Materials wear resistance toughness Coating Grade Description 05 10 15 20 25 30 35 40 45 Uncoated carbide. Extraordinarily good balance of hardness, wear resistance,edge stability, and toughness. Light and medium machining. For cast iron,K all non-ferrous metals, and non-metals. Useful in unfavourable conditions. N S HW-K15 H P M Uncoated carbide. Medium machining. For steel. HW-P25 P Uncoated carbide. Light and medium machining. For steel. To be used at low cutting speeds. Effective in unfavourable conditions. HW-P35 P M Cermet. Light machining. Extremely good wear resistance at higher cutting speeds.For steels and nodular cast iron. Recommended for high cutting speeds underK favourable conditions. HT-P15 B28 widia.com