Good quality inserts. As far as I know, no worse than Ken's Metal. I'm not a commercial locksmith, but I do mechanical work on a regular basis. They work great with both soft and slightly hardened steel. I also use it successfully on stainless steel.
Machining Stainless with the GBJ S12M SCLCR06 CCMT060204: Enhanced Precision and Efficiency
3 Review
π§ Accusize Tools Carbide APKT1604 0056 1604X10: Superior Quality and Precision Cutting Performance
3 Review
Excircle Indexable MTJNR1616H16 MWLNR1616H08 MCLNR1616H12
3 Review
π Suppliers of Tungsten Carbide Cutter Inserts
3 Review