Drill bit Proline 78090K, metal, Ø 9 mm, length 125 mm, 1 pc

The Proline 78090K metal drill bit, 9 mm in diameter and 125 mm in overall length, is a single straight-shank cutting tool made for precise metal drilling. Manufactured from high-class high-speed steel (HSS) with 5% cobalt and produced by full grinding, the bit provides accurate, straight holes and increased wear resistance. A 135° point angle with chamfering adjustment supports fast penetration and reliable centring on metal surfaces. Supplied as one piece in a blister pack, this drill bit is suitable for both hand-held and machine drilling applications.

Advantages

The cobalt-alloyed HSS construction delivers improved hardness and high temperature resistance, extending tool life during prolonged or demanding drilling. Ground flute geometry and straight shank manufacturing ensure high accuracy and rectilinearity of holes while the 135° point reduces walking and facilitates fast drilling starts. The design is optimized for challenging materials such as stainless, acid-resistant and high-alloy steels, titanium and cast irons, offering consistent performance in maintenance, repair and precision metalworking tasks.

Suitable for

• Drilling precise Ø 9 mm holes in steel and stainless steel
• Work with high-alloy and heat-resistant metals, including titanium
• Maintenance and repair tasks on machinery and metal structures
• Bench and hand-held drilling where straight shank bits are required

Key specifications

• Diameter: 9 mm
• Overall length: 125 mm
• Point angle: 135° with chamfering adjustment
• Material: high-speed steel (HSS) with 5% cobalt
• Manufacturing: fully ground flutes for high accuracy
• Intended materials: high-alloy steels, stainless and acid-resistant steels, titanium, cast iron and other hard-to-machine metals
• Shank type: straight shank for machine and manual use

How to use

Select an appropriate cutting speed and feed for the work material, secure the workpiece and use appropriate clamping. Fit the 9 mm straight-shank drill into the chuck or collet, ensure the drill is perpendicular to the surface for best rectilinearity, and apply steady pressure. Use coolant or cutting fluid when drilling high-alloy or stainless steels to reduce temperature and extend tool life. Retract periodically on deep holes to clear chips and avoid jamming.

Usage recommendations

Use medium to low cutting speeds and consistent coolant flow when working with stainless, high-alloy or titanium materials. Inspect the drill for wear and re-sharpen or replace when hole quality degrades to maintain accuracy and prevent workpiece damage.