Twist drill bit Irwin 10502558 — 6.5 mm diameter, single piece

Irwin 10502558 is a single-piece twist drill bit with a 6.5 mm cutting diameter designed for general and demanding drilling tasks. Made to DIN 338 standards with HSS-cobalt composition, this drill bit is intended for use in a range of metals where twist-drill geometry and a 6.5 mm hole are required. The 135° split point reduces walking at startup and the cylindrical shank fits standard chucks for straightforward mounting.

Advantages

The 5% cobalt HSS construction increases heat and abrasion resistance compared with standard high-speed steel, supporting drilling in tougher, heat-resistant alloys and hardened steels. The heavy-duty web and reinforced geometry provide greater strength and durability under load. The 135° split point improves centring and reduces the need for pilot holes, enabling more precise holes with less bit wandering.

Suitable for

• Drilling holes in alloyed steel
• Drilling in stainless steel and other metals
• General metal fabrication and maintenance tasks requiring a 6.5 mm hole

Key specifications

• Type: Twist drill bit
• Cutting diameter: 6.5 mm
• Overall length: 101 mm
• Material compatibility: alloyed steel, metal, stainless steel
• Shank type: cylindrical
• Quantity: 1 piece
• Point angle: 135° split point
• Material: HSS with 5% cobalt

How to use

Secure the drill bit in a compatible drill chuck, ensuring the cylindrical shank is fully seated and clamped. Mark and, if necessary, centre-punch the drilling location on the workpiece to improve initial positioning. Use appropriate cutting speed, feed and coolant or lubricant suitable for the metal being drilled; lower speeds and steady pressure are recommended for harder or heat-treated materials. Apply moderate, consistent feed until the required hole depth is reached, then withdraw the bit while the drill is still turning to clear chips.

Usage recommendations

For best results when drilling alloyed or hardened steels, use cutting fluid and reduced speeds to prolong bit life. Inspect the bit regularly for wear and regrind or replace if chipping or blunting is observed.