Dormer Pramet A125 5.50 mm x 200 mm HSS ST STRAIGHT SHANK EXTRA LONG SERIES DRILL BS 328

Dormer Pramet A125 5.50 mm x 200 mm HSS ST STRAIGHT SHANK EXTRA LONG SERIES DRILL BS 328 is a purpose-built solution for deep-hole drilling where reach and reliability matter most. This 5.50 mm diameter drill bit combines classic geometry with modern metallurgy to tackle demanding materials and tight spaces without sacrificing accuracy.

Key features designed for real-world machining:

• 118-degree conventional point delivers a strong, self-centering tip that starts cuts cleanly and resists walking on contact. The point is easy to re-grind, so you can restore sharpness quickly in-house and extend the tool’s productive life.
• Steam oxide finish reduces friction and prevents workpiece material from sticking to the cutting edge, helping chips break away smoothly and improving cycle times in steel and non-ferrous applications.
• Extra long length series specifies a generous 200 mm reach, making it ideal for drilling very deep holes, reaching into cavities, or working through multi-layer assemblies where standard-length bits fall short.
• Premium HSS material provides broad compatibility across a range of materials, including steel, aluminum, and stainless steel, while maintaining good edge retention and toughness under heavy milling or drilling loads.
• Straight shank (BS 328) compatibility ensures secure clamping in a wide variety of drill chucks and collets across milling machines, drill presses, and compatible tooling setups.
• Versatile performance designed for multiple applications—precision pilot holes, through-holes, and deeper drilling tasks—without needing to switch to a different tool for each material.

Practical use tips to get the most from this drill bit:

• Match speed and feed to the material: moderate speeds with steady feeds when drilling steel, and generous lubrication to manage heat and extend edge life. For stainless steel, consider slightly lower speeds to minimize work hardening.
• Use peck drilling to clear chips and prevent clogging in deep holes. Lift periodically to evacuate heat and swarf.
• Secure the workpiece firmly and center-punch the hole location to ensure precise entry and minimize wandering at start.

This drill bit is an excellent fit for professional workshops, maintenance departments, and hobbyists tackling projects that demand deep-hole capabilities without compromising on edge durability or material versatility. When you need a reliable, long-reach HSS drill that can handle steel, aluminum, and stainless steel with consistent performance, the Dormer Pramet A125 delivers.