Meet the Dormer Pramet A125 1/2 Inch x 400 mm HSS ST STRAIGHT SHANK EXTRA LONG SERIES DRILL BS 328 — a purpose-built drill bit crafted for serious deep-hole work. With its robust construction and smart engineering, this bit is designed to deliver precise starts, clean holes, and dependable performance in demanding fabrication environments.

• 118-degree conventional point creates a strong, self-centering tip that’s easy to re-sharpen in the field, helping you maintain accurate starts and reduce wandering in tough workpieces.
• Steam oxide finish minimizes material sticking to the cutting edge, promoting smoother chip evacuation and reduced friction during long drilling passes.
• Extra-long 400 mm length is specifically chosen for deep-hole drilling and applications where reach matters, letting you access through-thick sections without compromising rigidity.
• Premium HSS material handles a wide range of metals—from steel and aluminum to stainless steel—making it a versatile choice for mixed-material projects.
• Straight shank provides reliable grip and compatibility with standard drill chucks and collets, ensuring consistent performance on benchtop drills, drill presses, and milling machines.
• BS 328 compliance reflects established standards for quality and compatibility in professional metalworking.");

This drill bit is ideal for engineers, machinists, and hobbyists who regularly drill deep holes in thick workpieces or assemblies. Use it for fabricating chassis components, automotive brackets, machine bases, and other metalwork where depth and straightness are critical. Its 1/2 inch diameter balances aggressive material removal with control, while the 400 mm length provides the reach you need without sacrificing stability.

Practical tips for best results:

• Clamp the workpiece securely and use a pilot location to guide the bit on initial contact.
• Use a steady, moderate feed rate and appropriate cutting fluid to cool the bit and evacuate chips, especially in longer drilling passes.
• For deep holes, consider stepping drilling with a series of progressively larger bits to minimize deflection and heat buildup.
• Inspect the bit after use and re-sharpen the 118-degree point as needed to maintain an accurate starting surface.