DeWalt cobalt twist drill bit set for metal 6.5 mm, 10 pcs (DT4934)

DeWalt cobalt twist drill bit set DT4934 consists of ten 6.5 mm diameter straight-shank drills engineered for metalworking. The cobalt alloy composition increases hardness and heat resistance compared with standard HSS bits, making this set suitable for drilling stainless steel, hardened steels and other ferrous metals. Each bit features a cylindrical shank designed for secure clamping in standard drill chucks and workshop drilling machines.

Advantages

The cobalt construction provides improved wear resistance and sustained cutting performance at higher temperatures, reducing premature dulling when working with tough metals. The 6.5 mm diameter is a common size for through-holes, pilot holes and clearance holes in metal fabrication. Straight shanks ensure compatibility with a wide range of handheld and benchtop drills while the consistent tip geometry supports accurate centring and reduced walking on flat metal surfaces.

Suitable for

• Drilling stainless steel panels and sheet metal
• Creating clearance and through-holes in hardened steel components
• Workshop and maintenance tasks requiring repeatable metal holes
• Automotive and machinery repair where durable metal drilling is needed

Key specifications

• Material: cobalt alloy high-speed steel
• Drill diameter: 6.5 mm
• Shank type: cylindrical (straight) shank
• Point geometry: split/standard tip for centring on metal surfaces
• Package quantity: 10 pieces

How to use

Secure the appropriate drill bit in the drill chuck, ensuring the straight shank is tightly clamped and concentric. Mark the drilling position and, if needed, use a centre punch to prevent walking. Select a suitable cutting speed and apply steady pressure; use lower speeds and increased feed when drilling hardened steels. Apply cutting fluid or coolant to reduce heat build-up and extend bit life. Withdraw the bit periodically to clear chips and check hole progress.

Usage recommendations

Use reduced spindle speeds and continuous cutting lubricant when drilling stainless steel or hardened materials. Inspect bits for wear before use and replace any that show significant blunting or chipping to maintain hole quality and operator safety.