Drill bit Abraboro HSS cylindrical 3.9 mm — high-speed steel straight shank

Abraboro HSS cylindrical drill bit 3.9 mm is a straight-shank cutting tool designed for drilling through metal, wood and plastics. Made from high-speed steel (HSS), the bit balances hardness and toughness to deliver accurate, clean holes at moderate drilling speeds. The 3.9 mm diameter is suitable for pilot holes, precision fittings and general workshop or DIY tasks where a small, consistent hole is required. The cylindrical shank fits standard chucks on handheld drills and drill presses, providing stable rotation and simple bit changes.

Advantages

The HSS composition provides wear resistance and heat stability during continuous drilling, reducing premature dulling compared with standard carbon-steel bits. The straight cylindrical shank ensures secure clamping in standard drill chucks and reduces runout for improved hole accuracy. The 3.9 mm diameter offers a balance between precision and versatility for a wide range of materials, and the ground cutting edges enable clean hole walls and reduced burr formation when used at appropriate speeds and with correct feed pressure.

Suitable for

• Drilling small-diameter holes in mild steel and non-ferrous metals
• Creating pilot holes for screws and fasteners in wood
• Drilling acrylic, polycarbonate and other plastics with reduced chipping
• Workshop tasks using handheld drills or drill presses
• General DIY projects requiring accurate 3.9 mm holes

Key specifications

• Diameter: 3.9 mm
• Material: high-speed steel (HSS)
• Shank type: straight cylindrical shank
• Intended use: metal, wood, plastics
• Suitable for: handheld drills and drill presses

How to use

Mark the drilling point and secure the workpiece to prevent movement. Select the appropriate drilling speed for the material—lower speeds for harder metals, moderate speeds for wood and plastics—and fit the 3.9 mm Abraboro HSS bit into the drill chuck, tightening firmly. Apply steady, even feed pressure and clear chips periodically. For metal, use cutting fluid to reduce heat buildup and extend bit life; for plastics, use slower speeds or peck drilling to avoid melting. After use, clean chips from the flutes and store the bit in a dry place to prevent corrosion.

Usage recommendations

Use appropriate personal protective equipment, secure the workpiece, and choose recommended speeds and lubricants for the material being drilled. Inspect the bit before use and replace if worn or damaged to maintain hole quality and safe operation.