Twist drill bit set Irwin 8 mm, 5 pieces (model 10502534)

Irwin twist drill bit set comprises five identical 8 mm HSS cobalt twist drills designed for reliable metalworking and general-purpose drilling. Each bit is manufactured to DIN 338 standards with a heavy-duty web construction and a 135° split point that reduces walking and starts drilling immediately. The inclusion of 5% cobalt increases heat and abrasion resistance, making this set suitable for demanding tasks and repeated use with compatible hand drills and drill presses.

Advantages

The 5% cobalt composition provides enhanced hardness and thermal stability compared with standard high-speed steel, extending bit life under higher temperatures and abrasive conditions. Heavy-duty web construction adds torsional strength to resist breakage during heavy-duty use. The 135° split point geometry improves centring and reduces the need for pilot holes, while conformance to DIN 338 ensures consistent geometry and performance across the set.

Suitable for

• Drilling through hardened and heat-treated steels and abrasive alloys
• General metal fabrication and maintenance work
• Repeated production or workshop tasks requiring identical diameter bits
• Use with compatible hand drills and drill presses

Key specifications

• Drill diameter: 8 mm
• Quantity: 5 pieces per set
• Material: High-speed steel with 5% cobalt
• Point angle and geometry: 135° split point
• Standards: Manufactured to DIN 338 geometric specifications
• Construction: Heavy-duty web for increased strength
• Primary application: Tough metal and abrasive alloy drilling

How to use

Secure the workpiece and select the appropriate drill speed for the material to be drilled; use lower speeds for hardened steels and higher speeds for softer metals while observing manufacturer guidance for speed and feed. Install the straight-shank bit firmly in the drill chuck and ensure it is tightly clamped. Apply steady, moderate pressure and allow the 135° split point to cut without excessive force. Withdraw periodically to clear chips and, when drilling metal, use an appropriate cutting fluid to reduce heat and extend bit life.

Usage recommendations

For best performance when drilling hardened or abrasive alloys, use reduced spindle speeds, consistent cutting fluid, and avoid excessive feed rates. Inspect bits for wear or chipping before use and replace when cutting efficiency declines to maintain hole quality and prevent tool failure.