Drill bit Proline 77675 — metal, 7.5 mm diameter, 290 mm length, 1 pc

Proline 77675 is a single high-speed steel (HSS) drill bit designed for metalworking applications. With a 7.5 mm diameter and an overall length of 290 mm, this extra-long bit reaches deeper workpieces and creates accurate through-holes in steel, non-ferrous metals and plastics. The bit is fully ground to ensure straightness and dimensional accuracy, and it fits standard drill chucks for use in workshop drills and portable drilling machines.

Advantages

The 135° point angle with chamfering adjustment reduces walking and improves centring on metal surfaces, enabling faster hole starts and more consistent results. Full grinding of the flute and point provides precise rectilinearity and stable cutting geometry for repeatable hole quality. Manufactured from refined HSS, the drill bit offers hardness and wear resistance appropriate for machining steel and similar materials. The extra length facilitates drilling through thicker parts or reaching confined areas without repositioning the workpiece.

Suitable for

• Drilling through-holes in steel sheets and structural parts
• Creating medium-diameter holes in non-ferrous metals (aluminium, brass)
• Workshop and on-site construction drilling tasks
• Drilling in plastics where a straight long-reach bit is required

Key specifications

• Material: refined high-speed steel (HSS)
• Diameter: 7.5 mm
• Overall length: 290 mm (extra long)
• Point angle: 135° with chamfering adjustment for quick starts
• Design: fully ground flute and point for high straightness and accuracy
• Packaging: single piece per case

How to use

Secure the drill bit in a compatible drill chuck and clamp the workpiece to prevent rotation. Select an appropriate spindle speed for the material being drilled (lower speeds for harder steels, higher speeds for non-ferrous metals and plastics) and apply steady feed pressure. Use cutting fluid or coolant when drilling steel to extend tool life and improve chip evacuation. For deeper holes, withdraw periodically to clear chips and reduce heat buildup. After use, clean and store the bit in its case to avoid damage and corrosion.

Usage recommendations

Use cutting lubricant when drilling steel, start with a pilot mark or centre punch to improve accuracy, and choose a drill speed matched to the material to balance cutting performance and tool life.