Bosch HSS-Co Twist Drill Bit 8.5 x 117 mm

This single-piece HSS-Co twist drill bit from Bosch is made for demanding metalworking tasks. The cobalt-alloyed steel is formulated to handle heat build-up and resist wear under heavy friction, so it can drill tougher, denser metals that standard high-speed steel struggles with. It is rated for continuous use in stainless steel, non-alloyed steel, cast iron, and cast steel. The bit geometry helps a machinist start a hole accurately on smooth surfaces. The construction makes it a dependable choice for tradespeople who need consistent results in hard-to-drill materials.

A cylindrical shank anchors the tool securely in standard handheld rotary drills and benchtop drill stands. The geometry helps keep the bit stable during demanding fabrication work. Waste material is cleared efficiently during cutting, leaving a clean bore. Steady debris removal reduces friction and extends the working life of the bit. The straightforward shank design allows for quick changes between tasks without specialised chuck adapters. This profile gives a practical balance of reach and rigidity for typical workshop use.

• 8.5 mm drill bit diameter produces accurately sized holes for matching hardware.
• 117 mm overall length sets the maximum clearance of the installed bit.
• 75 mm working length defines the deepest continuous bore achievable in a single pass.
• Two cutting edges shear waste material for steady downward progress.
• Bronze colour provides clear visual differentiation from standard high-speed steel bits.