Dormer Pramet A125 31/64 Inch x 310 mm HSS ST STRAIGHT SHANK EXTRA LONG SERIES DRILL BS 328

Meet the Dormer Pramet A125 31/64 Inch x 310 mm HSS ST Straight Shank Extra Long Series Drill BS 328 — a purpose-built drill bit designed for deep-hole projects where reach and precision matter most.

What makes it different

• 118-degree conventional point delivers a strong, self-centering start that resists wandering and maintains accurate hole geometry. This point profile dosed with the ability to be re-ground, meaning you can refresh the cutting edge to extend tool life without sacrificing accuracy.
• Steam oxide finish minimizes built-up edge and material sticking to the cutting edge, helping you achieve cleaner starts and smoother chip evacuation, especially on steels and alloys encountered in fabrication work.
• Extra-long length series provides significant reach for deep holes and hard-to-access workpieces. When a standard drill can’t get through a thick plate or into a recessed cavity, this drill’s 310 mm length (12.2 inches) makes the difference.
• Premium HSS material offers robust performance across a range of materials — from steel and stainless steel to aluminum and other non-ferrous metals — with consistent hardness and wear resistance under demanding drilling conditions.
• Straight shank design ensures compatibility with most drill chucks and machine setups, delivering dependable grip and concentricity for long, precise holes.
• BS 328 compliance confirms standardization and reliability for industrial use, so you can trust performance in professional shop environments.

Best uses and practical tips

This Dormer Pramet A125 drill is ideal for deep-hole drilling tasks where a standard-length bit won’t suffice. Think automotive fabrication, machinery housings, or thick structural components, where you need to bore clean, straight holes all the way through with minimal chatter.

• Use appropriate cutting fluid or coolant to manage heat, especially when drilling stainless steel or other hard alloys.
• Start with a light, centered pilot to ensure the 118° point engages cleanly, then advance gradually to prevent deflection.
• Maintain steady feed pressure and avoid pushing aggressively at full depth—let the bit cut and chip away steadily for the best hole quality.
• After use, inspect the edge and re-grind if necessary to restore the point geometry and extend tool life.

Who benefits most

Ideal for machinists, fabricators, and workshop professionals who regularly drill deep holes in steel, stainless steel, and aluminum. If your workflow calls for long-reach drilling without compromising precision, the A125 is engineered to deliver consistent results, reduce setup time, and minimize tool changes on mid-to-high volume projects.

Why choose this over shorter alternatives

While shorter bits excel in rigidity and speed for shallow holes, the A125’s extra-long length maximizes reach without sacrificing cutting performance. The combination of a robust HSS core, steam oxide finish, and a grind-ready 118-degree point means you get reliable hole quality and longer life in challenging deep-hole applications, reducing the need for frequent tool changes and rework.