Drill bit Proline 78080K, metal, Ø 8 mm, length 117 mm, 1 pc

Proline 78080K is a single HSS-Co metal twist drill with an 8 mm diameter and a total length of 117 mm, intended for drilling through a wide range of metals and hard-to-machine materials. The drill features a 135° point angle with chamfering adjustment and is produced by full grinding to ensure high accuracy and straightness of holes. Its standard shank allows use in hand drills and drill presses, making it suitable for workshop repairs, metal fabrication and general maintenance tasks.

Advantages

The drill is made from high-class high-speed steel alloyed with 5% cobalt, which increases hardness and resistance to elevated temperatures during cutting. The 135° point with chamfering adjustment enables quicker center finding and reduced walking at the start of drilling. Fully ground geometry ensures precise hole tolerances and consistent concentricity. The design supports drilling in high-alloy steels, titanium, acid-resistant and stainless steels, creep-resisting steels and cast iron, providing longer life and stable performance under heavy-duty conditions.

Suitable for

• Drilling holes in high-alloy and stainless steels
• Work on titanium and acid-resistant materials
• Workshop repairs and maintenance tasks
• Metal fabrication and assembly operations
• Use in hand drills and drill presses for general-purpose metalworking

Key specifications

• Material: high-speed steel with 5% cobalt (HSS-Co)
• Diameter: 8 mm
• Total length: 117 mm
• Tip geometry: 135° point angle with chamfering adjustment
• Manufacture: fully ground flutes for accuracy and straightness
• Temperature resistance: high resistance to elevated cutting temperatures
• Suitable materials: high-alloy steels, stainless and acid-resistant steels, titanium, creep-resisting steels, cast iron and similar hard-to-machine metals
• Shank type: standard cylindrical shank compatible with common drill chucks

How to use

Clamp the drill bit securely in a suitable drill chuck, ensuring concentric runout is minimal. Mark the drilling position and, if necessary, use a center punch to improve positioning. Select an appropriate cutting speed and feed for the material being drilled; lower speeds and steady feed rates are recommended for high-alloy and stainless steels. Use cutting fluid or coolant when drilling heat-sensitive or hard materials to reduce temperature, improve chip evacuation and extend tool life. Retract the bit periodically on deep holes to clear chips.

Usage recommendations

For best results, use appropriate cutting speeds for HSS-Co drills, apply suitable coolant for stainless and high-alloy materials, and avoid excessive feed that can cause chipping. Regularly inspect the drill for wear and maintain a sharp cutting edge; fully ground drills perform best when kept sharp. Store the bit in its blister pack or a dedicated holder to prevent damage to the cutting edges.