Drill bit set Proline 78050K — 2 pcs, metal, Ø 5 mm, length 86 mm

The Proline 78050K drill bit set includes two 5 mm diameter, 86 mm long metal drill bits designed for precise drilling in metal and other hard materials. These straight-shank HSS bits with 5% cobalt content are made by full grinding to ensure straightness and dimensional accuracy of holes. A 135° point angle with chamfering adjustment supports fast penetration and helps maintain accurate marking out, while the high-temperature resistance extends tool life during demanding metalworking tasks. The set is supplied in a blister pack for secure storage and handling.

Advantages

Manufactured from high-class HSS steel alloyed with 5% cobalt, these drill bits offer increased hardness and wear resistance for use in high-alloy and difficult-to-machine steels. The fully ground construction ensures rectilinearity and consistent hole diameter. A 135° point angle with chamfering adjustment enables faster drilling and reduced walking at the start of the cut. High temperature resistance allows prolonged operation under load without rapid loss of cutting geometry.

Suitable for

• Drilling holes in high-alloy steels and stainless steels
• Working with titanium and acid-resistant materials
• Metal fabrication, mounting and assembly operations
• General repair and maintenance that require precise 5 mm holes

Key specifications

• Material: High-speed steel (HSS) with 5% cobalt
• Diameter: 5 mm
• Overall length: 86 mm
• Point angle: 135° with chamfering adjustment
• Manufacturing method: Fully ground flute and cutting geometry
• Temperature resistance: Designed for high-temperature cutting conditions
• Shank type: Straight shank suitable for hand drills and drill drivers
• Pack contents: 2 drill bits supplied in blister packaging

How to use

Select a drill speed and cutting fluid appropriate for the workpiece material and secure the workpiece firmly before drilling. Mount the straight shank securely in the drill chuck, align the tip with the marked centre, and start drilling at low speed to establish the hole without walking. Apply steady feed pressure and moderate speed for metalworking; use cutting fluid when drilling stainless, high-alloy, or titanium materials to reduce heat and prolong bit life. Retract occasionally to clear chips when drilling deep holes.

Usage recommendations

For best results, use cutting fluid when drilling stainless, high-alloy, or titanium materials and adjust drill speed according to material hardness. Inspect drill tip geometry periodically and replace bits when wear degrades hole accuracy or increases required feed force.