Twist drill bit set Irwin 10502524 — 10 pcs, 4.5 mm diameter

Irwin 10502524 is a set of ten 4.5 mm twist drill bits made from HSS with 5% cobalt. Designed and manufactured to DIN 338 standards, these drill bits feature a heavy-duty web construction and a 135° split point that reduces bit walking and starts cutting immediately. Each bit has a cylindrical shank and an overall length of 80 mm, providing a balanced combination of strength and rigidity for demanding drilling tasks in metals and other compatible materials.

Advantages

The inclusion of 5% cobalt increases heat and abrasion resistance compared with standard high-speed steel, extending tool life during prolonged or high-temperature drilling. Heavy-duty web construction improves torsional strength and durability, while the 135° split point minimises walking and helps produce accurate pilot holes. Compliance with DIN 338 ensures consistent geometry and performance across the set of ten identical bits.

Suitable for

• Drilling holes in alloyed steels and stainless steel
• Pilot holes and general-purpose metalworking
• Applications requiring higher heat resistance such as abrasive or hardened metal drilling
• Use with standard hand drills and drill presses that accept 4.5 mm cylindrical shanks

Key specifications

• Drill type: Twist drill (HSS cobalt)
• Diameter: 4.5 mm
• Overall length: 80 mm
• Material composition: High-speed steel with 5% cobalt
• Point angle and design: 135° split point
• Shank type: Cylindrical
• Quantity: 10 pieces
• Manufacturing standard: DIN 338

How to use

Secure the appropriate Irwin 4.5 mm bit in the chuck of a compatible drill or drill press. Use cutting fluid or coolant when drilling stainless steel or other heat-sensitive alloys to reduce heat buildup and extend bit life. Start drilling at low speed to establish the hole, then increase speed as needed while maintaining steady pressure; the 135° split point helps prevent walking at the start. Periodically retract the bit to clear chips and inspect the cutting edges. Replace bits from the set when wear begins to affect hole quality.

Usage recommendations

For best results when drilling hardened or stainless steels, use light cutting feed, moderate speed and a suitable cutting lubricant. When drilling thicker sections, peck-drill to clear chips and avoid overheating. Store bits in their original packaging or a dedicated holder to protect cutting edges and maintain consistent performance across the set.