kwb Reamers & Countersinks Countersink drill bit 610379 - KWB 704310, The kwb 704310 Countersink drill bit is manufactured by kwb and features a 112 mm length. Designed for precision machining, it is ideal for creating smooth, conical recesses for countersunk screw heads. This drill bit is suitable for use with various materials in both professional and DIY settings. kwb 704310 Countersink Drill Bit 112mm tool steel 90° 5-cut