Twist drill bit Bosch HSS hex-shank 8.5 mm

Impact Control HSS twist drill bit with an 8.5 mm diameter and 1/4-inch hex shank, designed for precision drilling in metal and suitable for use with impact drivers. The bit is precision-ground from solid high-speed steel (HSS) and features an oxide-coated flute to reduce wear. It is manufactured to DIN 338 with a Type N flute geometry, a 135° split-point tip for active cutting and reliable centring, and a diameter tolerance of h8. Supplied as a single piece in a blister pack.

Advantages

The HSS construction and precision grinding provide good cutting performance and durability when drilling metal and wood. The oxide-coated flute reduces friction and wear, while the 135° split-point tip improves centring and reduces walking at the drill start. The 1/4-inch hex shank ensures secure grip in chucks and quick-change holders, making the bit suitable for impact drivers and standard drills.

Suitable for

Key specifications

How to use

Select an appropriate drill speed and secure the drill bit in the chuck or quick-change holder so the hex shank is fully engaged. Mark the drilling position and start at low speed to establish the centre, then increase speed and apply steady, even pressure. For drilling metal, use cutting fluid or lubricant to extend tool life and reduce heat. Withdraw the bit occasionally to clear chips and avoid overheating.

Recommendations

Use the 8.5 mm HSS hex-shank bit with compatible impact drivers or drills. For best results in metal, keep the bit cool with cutting fluid and avoid excessive feed pressure. Replace the bit if cutting performance declines or if the tip becomes visibly worn.