Drill bit Proline 79085K, metal, Ø 8.5 mm, length 117 mm, 1 pc

Proline 79085K metal drill bit is a single HSS cutting tool with an 8.5 mm diameter and 117 mm overall length, designed for drilling metal and similar hard materials. The straight shank fits standard hand drills and drill presses, providing a precise 8.5 mm hole for general metalworking, fabrication, mounting and maintenance tasks. The bit features ground cutting edges and a 135° point angle with chamfering adjustment to assist fast centre penetration and reduced walking.

Advantages

The refined high-speed steel construction offers wear resistance and consistent cutting performance when used at appropriate speeds and with coolant or cutting oil. The 135° point angle and chamfering adjustment reduce the need for extensive centre punching and enable faster drilling starts, while ground edges maintain sharpness and improve hole quality. The straight shank allows secure clamping in standard chucks of hand drills and drill presses.

Suitable for

• Drilling through mild steel, stainless steel alloys and other ferrous materials
• Fabrication and sheet metal work where an 8.5 mm hole is required
• Maintenance, repair and mounting tasks in workshops and on-site
• Use in handheld electric drills and bench drill presses

Key specifications

• Diameter: 8.5 mm
• Overall length: 117 mm
• Material: refined high-speed steel (HSS)
• Point angle: 135° with chamfering adjustment
• Shank type: straight shank for standard chucks
• Cutting edges: precision ground

How to use

Secure the drill bit in the chuck so that the straight shank is fully gripped and concentric. Select a drill speed appropriate for the material being drilled and apply cutting fluid when drilling harder metals to extend tool life and improve chip evacuation. Start drilling with light pressure to establish the centre and then increase feed evenly; for thicker or tougher materials use progressive drilling with pilot holes if necessary. After use, clean chips and store the bit in its blister pack or a suitable holder to protect the ground edges.

Usage recommendations

Use cutting oil or coolant for stainless steels and other hard alloys, choose rotational speed and feed according to material hardness, and ensure correct clamping to prevent runout. Replace the bit when wear or chipping affects hole accuracy or cutting efficiency.