Drill bits Bosch HSS-Co Pilot, length 65 mm, high-speed steel cobalt (HSS-Co)

Bosch HSS-Co Pilot drill bits, length 65 mm, are pilot drills manufactured from high-speed steel with cobalt alloy (HSS-Co) that provide improved heat resistance and extended wear life compared with standard HSS bits. These pilot bits are designed to create precise starter holes and to guide hole saws or larger drill bits during metalworking and general mechanical tasks. They are suitable for use in both corded and cordless drill drivers and can be used in handheld or bench drills to reduce walking and ensure accurate drilling starts.

Advantages

The cobalt-enhanced HSS-Co construction increases hardness and thermal stability, allowing the bit to retain cutting performance under higher temperatures and heavier loads. The 65 mm overall length gives sufficient reach for pilot hole applications while maintaining rigidity for accurate guidance. The geometry of the tip is optimized for dependable centring and reduced walking, which improves safety and repeatability when positioning hole saws or larger drills. Compatibility with common drill drivers makes these pilot bits convenient for workshops and mobile trades.

Suitable for

• Creating pilot holes for hole saws and large-diameter cutters
• Metalworking tasks involving steel and other ferrous materials
• General mechanical assembly and maintenance where precise starts are required
• Use in handheld or bench drill machines with corded or cordless drivers

Key specifications

• Material: high-speed steel with cobalt alloy (HSS-Co) for improved heat resistance
• Overall length: 65 mm
• Tip design: pilot/centering geometry to reduce walking and ensure accurate starts
• Intended application: pilot drilling to guide hole saws and larger drills in metalworking and general mechanical tasks
• Compatibility: suitable for use in corded and cordless drill drivers, handheld and bench drills

How to use

Select a pilot bit of the required diameter and secure it properly in the drill chuck. Mark the drilling location and, if possible, clamp or secure the workpiece to prevent movement. Start drilling at low speed to allow the tip to centre and create an initial guide hole, then increase speed as appropriate for the material while maintaining steady pressure. Use cutting fluid or coolant when drilling ferrous metals to reduce heat and prolong bit life. After use, clean chips from the flutes and store the bit in a dry place to avoid corrosion.

Usage recommendations

For best results when drilling metal, use appropriate cutting fluid and moderate feed pressure; avoid excessive speed that can overheat the cobalt alloy. When guiding hole saws, confirm the pilot bit length provides adequate engagement with the workpiece for stable centring. Replace the pilot bit if tip wear or chipping reduces centring accuracy.