Drill bit Proline 78140 — 14 mm diameter, 160 mm length, metal

The Proline 78140 drill bit is a single 14 mm diameter, 160 mm overall length metalworking bit designed for precise drilling in steel and other ferrous materials. Machined entirely by grinding from high-speed steel with 5% cobalt (HSS-Co), this bit features a 135° point angle with chamfering adjustment, offering rapid penetration and accurate centring for through-holes and clearance holes. Its heat-resistant composition and ground geometry maintain cutting performance during demanding metalworking, repair and maintenance operations.

Advantages

This drill bit combines HSS-Co material with full grinding production to provide high dimensional accuracy and straightness of holes. The 135° point reduces walking and improves guidance when starting holes, while the chamfering adjustment shortens setup time and improves surface finish. Enhanced heat resistance and cobalt alloying increase durability when drilling high-alloy, stainless, acid-resistant, creep-resisting steels, titanium and cast iron. Supplied as a single piece, the bit is suitable for both hand drills and drill presses.

Suitable for

• Drilling through-holes and clearance holes in structural and stainless steels
• Metal repair, maintenance and fabrication tasks
• Work with high-alloy, corrosion-resistant and creep-resisting materials
• Use in hand-held drills and drill presses for accurate holemaking

Key specifications

• Cutting diameter: 14 mm
• Overall length: 160 mm
• Point angle: 135° with chamfering adjustment
• Material: high-speed steel with 5% cobalt (HSS-Co)
• Manufacturing: fully ground flute geometry for high accuracy
• Suitable materials: high-alloy steels, stainless and acid-resistant steels, titanium, cast iron and other hard-to-machine ferrous materials

How to use

Mark the hole location and secure the workpiece to prevent movement. Use a centre punch if required to aid starting. Select appropriate cutting speed and feed for HSS-Co drills and the specific workpiece material; lower speeds are recommended for hard or heat-sensitive alloys. Apply steady, moderate pressure and allow the drill to cut—avoid excessive force that can overheat the bit. Use cutting fluid or coolant when drilling stainless, high-alloy steels or titanium to extend bit life and improve chip evacuation. Clear chips frequently and retract the drill periodically for cooling when performing long-hole drilling.

Usage recommendations

For best results, use the Proline 14 mm HSS-Co drill bit in a properly aligned chuck, maintain recommended RPMs for the material being drilled, and employ cutting fluid when working with stainless or heat-resistant alloys. Store the bit in its protective plastic tube to prevent damage to the cutting edges.