Meet the Dormer Pramet A125 5/16 Inch x 310 mm HSS Straight Shank Extra Long Series Drill BS 328. Engineered for metalworking professionals who need serious reach without sacrificing control, this drill combines a robust tip with extraordinary length to conquer deep-bore tasks with precision.

Key features and benefits

• 118-degree conventional point — a tough, self-centering tip that starts cleanly and is straightforward to re-sharpen, helping you achieve accurate starts and extend tool life in busy workshops.
• Steam oxide finish — lowers friction and minimizes material sticking to the cutting edge, promoting smoother drilling and reduced heat buildup.
• Extra long length (310 mm) — designed for drilling very deep holes and reaching recessed areas where standard drills won’t reach, while maintaining rigidity and alignment.
• Premium HSS material — high-speed steel delivers reliable performance across a variety of metals, including steel, aluminium, and stainless steel, making it a versatile choice for mixed-material projects.
• Straight shank design — compatible with standard drill chucks and machines, providing stable torque transfer and straightforward setup.
• BS 328 designation — part of a recognized standard, helping you organize and select the right drill for deep-hole applications in professional shops.

Ideal use cases

Perfect for fabricators, maintenance technicians, and metal hobbyists who routinely drill deep into thick materials. The A125 excels in through-holes and deep-pocket drilling where length and reach are critical, such as long bore accesses in steel, aluminum workpieces, or stainless components. Its 5/16 inch diameter offers a practical balance between material removal and hole precision, making it a go-to for projects that demand both capability and reliability.

Practical tips for best results

• Begin with a gentle, controlled feed to ensure the 118° tip engages cleanly and minimizes wandering.
• Apply light cutting fluid to reduce heat and extend tool life when drilling tougher metals.
• For very deep holes, periodically retract the drill to clear chips and maintain consistent cutting action.
• Resharpen the tip as needed to preserve an accurate start and clean hole edges.