Review on 🔧 Migiwata Cobalt Steel Twist Cutting Tools in Industrial Drill Bits with Fractional Features by Jermaine Munajj

I ordered these bits to work with custom tools. My client bought one of the very first Shopsmith lathes to ever roll off the assembly line just after WWII. The spindle size on each lathe made from this first experimental model is 5/8 inch 20 TPI (threads per inch), but on this first model they machined 1/2 inch 24 TPI hardened drill stock. Customer needs adapter for coupling f 1/2” 24 t/d to m1” 8 t/d. After checking the recommended bit size for the threaded hole, I ordered these bits. They are the perfect size and cut through 440 stainless steel without excessive heat. Although not HSS cutters, they maintained their edge for a total of 3_1" holes before requiring resharpening and reshaping. While not normal workshop quality, they will cut the required 6 vias and help me to my new little hole. The boring pole is coming. I recommend them for the home store. They cost about 1/10th the cost of professional bits and provide a clean cut when you're in a pinch. I ran them at 58 fps and used cutting fluid to cool them down and blast freezing hardened the tool's surface by 50/1000 after threading. Absolutely perfect bit size for those fine machine threads. I definitely recommend them.