Carlyle 8.5mm HSS Cobalt 5% Drill Bit (CBD85)

Description

Genuine Carlyle · Part no. CBD85

The Carlyle CBD85 is an 8.5mm cobalt drill bit, the tapping drill for M10 threads, in M35 high speed steel with 5% cobalt to DIN 338. It has a 130-degree split point and a three-flat shank that the chuck can grip without the bit spinning, which matters when cutting a hole this size in steel or stainless.

Good to know

• Which tap goes with an 8.5mm hole? An M10 coarse thread tap. Drill square to the surface, then tap slowly with cutting fluid.
• What does the three-flat shank do? It gives the chuck jaws flat faces to grip, so the bit is less likely to slip and spin under load.
• Should I pilot drill? Yes, in steel a smaller pilot hole first makes an 8.5mm hole far easier and keeps it on centre.

Which one?

For M8 threads you'd need a 6.8mm tapping drill; for an M8 bolt to pass through, see the Carlyle 9mm HSS Cobalt 5% Drill Bit (CBD9). The Carlyle 8mm HSS Cobalt 5% Drill Bit (CBD8) is just below this size.

Key features

• 8.5mm HSS cobalt drill bit
• M10 tapping drill size
• Three-flat shank for a secure grip
• 130-degree split point
• M35 steel, 5% cobalt, DIN 338

Specification