Drill bit Proline 77642 — metal, Ø 4.2 mm, length 220 mm, 1 pc

Single Proline 77642 metal drill bit with a 4.2 mm cutting diameter and a total length of 220 mm. Made from high-quality refined HSS, this extra-long straight-shank drill is fully ground to ensure accurate, straight holes and is suitable for handheld drills and drill presses. The 135° point angle with chamfering adjustment allows faster penetration and reduces the need for extensive marking out, making the bit suitable for through-holes, panel work and metal fabrication where a long, precise 4.2 mm hole is required. Supplied as one piece and intended for use in steel, non-ferrous metals and plastics.

Advantages

The drill's fully ground geometry provides high accuracy and rectilinearity, which improves hole quality and repeatability. A 135° point angle with chamfering adjustment facilitates quick drilling and reduces burr formation. The extra length (220 mm) allows drilling through thicker assemblies and reaches confined or recessed areas without the need for extensions. Manufactured from refined high-speed steel (HSS), the bit offers durability and consistent cutting performance in metal and related materials.

Suitable for

• Drilling through-holes in thin and medium-thickness steel sheets
• Panel work and metal fabrication where long reach is required
• Drilling in non-ferrous metals and plastics
• Use with handheld drills and drill presses for precise 4.2 mm holes

Key specifications

• Cutting diameter: 4.2 mm
• Total length: 220 mm
• Shank type: straight shank for standard chucks
• Material: refined high-speed steel (HSS)
• Point geometry: 135° point angle with chamfering adjustment
• Finish: fully ground flutes for accuracy and rectilinearity
• Intended materials: steel, non-ferrous metals, plastics
• Quantity: 1 piece

How to use

Select a suitable drill holder or chuck that securely grips the straight shank, then clamp the workpiece to prevent movement. Mark the drilling location and, if necessary, use a center punch or drill bush for exact positioning. Begin drilling at low speed to establish the hole, then increase speed appropriate to the material while applying steady pressure and adequate coolant or cutting fluid for metal work. Maintain alignment to preserve hole straightness; withdraw occasionally to clear chips on deep holes. After drilling, deburr the hole if required.

Usage recommendations

For best results in steel and other metals, use cutting fluid to reduce heat and extend tool life. Match drill speed to the material hardness—lower speeds for harder steels, medium speeds for non-ferrous metals and higher speeds for plastics. When drilling long holes, periodically withdraw the drill to evacuate chips and avoid clogging the flutes.