25/64 Solid Carbide Drill Bits are USA Made of solid micro grain carbide. Solid Carbide Drill Bits are Industrial Quality Wholesale Drill Bits designed for drilling abrasive materials such as cast iron, non-ferrous alloys, high silicon aluminum, copper plastics, bronze, hard rubber, and plexiglass. 25/64 Solid Carbide Drill Bits have a .3906 decimal equivalent, 2-7/8 flute length, and 4-1/2 OAL. Call the sales staff at Bisco of Florida 1-866-247-2635 with questions on drill bits and solid carbide drill bits.