Dormer Pramet A125 1/2 Inch x 250 mm HSS ST STRAIGHT SHANK EXTRA LONG SERIES DRILL BS 328

The Dormer Pramet A125 1/2 Inch x 250 mm HSS straight shank drill is built for serious deep-hole work without compromising precision or durability. This extra-long drill combines a robust cutting edge with smart design to tackle lengthy holes in a range of materials, from steel to aluminum and stainless steel.

Key features that matter in real-world drilling

• 118-degree conventional point — creates a strong, self-centering tip that starts quickly and remains stable on contact. The geometry also makes re-grinding more straightforward, helping you extend the tool’s life between sharpenings.
• Steam oxide finish — a protective coating that reduces friction and minimizes material buildup on the cutting edge, promoting cleaner holes and less chatter during operation.
• Extra-long length series — specifically designed for drilling very deep holes and applications where extended reach is required, without sacrificing rigidity at the point of contact.
• Premium HSS material — versatile enough to drill through a variety of metals, including steel, aluminum, and stainless steel, making it a reliable workhorse across job sites and workshops.
• Straight shank, standard compatibility — fits a wide range of drill chucks and machines, ensuring quick swaps on busy benches and CNC setups alike.

Whether you’re fabricating a long through-hole, drilling into thick material plates, or threading an internal channel that demands precise depth control, this drill delivers consistent performance from start to finish. The A125 designation signals Dormer Pramet’s commitment to durable tooling that stands up to repeated use in demanding environments.

Ideal applications and use cases

• Long through-holes in steel, aluminum, and stainless steel for fasteners, hinges, and structural components.
• Deep-hole drilling in fabrication, automotive assemblies, and machinery housings where reach matters as much as precision.
• Controlled depth drilling on machines and drill presses that require a reliable, straight-shank tool with predictable exit quality.

Because this drill is part of a premium HSS lineup, it handles high cutting forces while maintaining a sharp edge. Use cutting fluid or appropriate coolant when drilling harder materials to extend tool life and achieve smoother chip evacuation, especially in deeper holes where heat buildup can be a concern.

Specifications at a glance

• Diameter: 1/2 inch
• Overall length: 250 mm
• Shank: Straight
• Material: High-Speed Steel (HSS)
• Finish: Steam oxide
• Series: Extra Long
• Point angle: 118 degrees
• Standard: BS 328

Practical tips for best results

• Begin with a light pilot drill if you’re working in harder materials to minimize walk and improve alignment.
• Maintain steady feeds and avoid aggressive plunging. Let the tool do the cutting, especially in deep holes where heat can accumulate.
• Inspect the flute clearance and chip evacuation path—deep holes require efficient removal of chips to prevent clogging and rubbing.
• Sharpen when you notice increased drift, wandering, or slower cutting performance. The 118-degree point regrinds relatively well and supports extended tool life with proper care.

This drill is designed for professionals who demand reliable performance across a spectrum of materials and applications. Choose the Dormer Pramet A125 for deep-hole projects where reach, rigidity, and consistent hole quality matter most—whether you’re outfitting a production line or tackling a one-off fabrication task.

Ready to enhance your deep-drilling capabilities? Add the Dormer Pramet A125 1/2 Inch x 250 mm HSS straight shank drill to your toolkit and experience precise, repeatable results from the first hole to the last.