Dormer Pramet A125 4.00 mm x 310 mm HSS ST STRAIGHT SHANK EXTRA LONG SERIES DRILL BS 328

Engineered for precision and depth, the Dormer Pramet A125 4.00 mm x 310 mm HSS ST Straight Shank Extra Long Series Drill BS 328 is a trusted tool for deep-hole metalworking. Designed to perform across a range of materials—from steel and aluminum to stainless steel—it delivers consistent, reliable results in demanding setups and long-reach applications.

• 118-degree conventional point — a strong, self-centering tip that starts cleanly on contact and is straightforward to re-grind when sharpening is needed, reducing downtime on the shop floor.
• Steam oxide finish — minimizes chip adhesion and friction at the cutting edge, promoting smoother entry, cleaner holes, and easier chip evacuation.
• Extra long length (310 mm) — specifically designed for drilling very deep holes and accessing recessed or hard-to-reach areas without compromising rigidity or accuracy.
• Premium HSS material — a versatile choice for drilling a wide range of materials, including steel, aluminum, and stainless steel, delivering dependable performance across multiple jobs.
• Straight shank design — compatible with a broad array of chucks and spindle interfaces, ensuring stable alignment and consistent runout control in both manual and CNC machines.
• Versatile, long-life solution — a practical, all-in-one option for fabrication, maintenance, and prototype work where deep bores and precision are required.

Who benefits most: machinists, fabricators, maintenance technicians, and model-makers who routinely drill deep or recessed features, such as engine components, hydraulic fittings, or tubular assemblies. The A125 Extra Long series reduces tool changes and setup time, helping you complete complex bores with a single, reliable drill.

Practical guidance for optimal results: use a light lubrication or coolant to extend tool life, employ a pecking drilling technique to clear chips on deep holes, and start with a pilot hole if the workpiece material presents extra hardness. Keep the point sharp and store with proper protection to maintain edge retention for longer‑lasting performance.