Dormer Pramet A125 5/8" x 460 mm HSS Straight Shank Extra Long Drill (BS 328) is built for serious deep-hole work. With a 5/8" diameter and a substantial 460 mm length, this drill delivers reliable reach for long-hole drilling tasks without sacrificing performance or control. Whether you’re fabricating a thick steel component or chasing a precise through-hole in a large aluminium or stainless steel workpiece, this tool is designed to keep you productive from start to finish.

The 118-degree conventional point provides a strong, self-centering start that stays true through the cut and remains easy to re-sharpen when needed. Paired with a steam oxide finish, it helps prevent material from sticking to the edge and promotes smoother chip evacuation—cutting heat is minimized and tool life is extended during heavier drilling cycles.

Key features and why they matter

• Extra-long length (460 mm): reach deep into workpieces and accommodate fixtures or assemblies where standard-length drills fall short.
• Premium HSS material: versatile for drilling a range of metals, including steel, aluminium, and stainless steel, delivering dependable performance across common fabrication tasks.
• Steam oxide finish: reduces workpiece stickiness and improves chip flow, helping maintain a clean cut and consistent diameter.
• Straight shank: compatibility with a wide array of drill chucks and machines, from benchtop drill presses to CNC setups.
• BS 328 specification: trusted standard that aligns with industry expectations for long-reach, high-precision drilling tools.

Practical use cases

• Deep-hole drilling in structural steel components where access is limited and hole depth is substantial.
• Long-reach through-holes in automotive chassis, heavy equipment housings, or large fabrication projects.
• Precision drilling in aluminium and stainless steel where exact hole diameter and clean entry are critical.
• Prototyping or maintenance work where an extra-long drill reduces setup time and improves first-pass accuracy.

Tips for best results

• Use a stable workholding setup and a slow, steady feed to maximize accuracy and tool life on deep holes.
• Apply a suitable cutting fluid or coolant when drilling steel or stainless steel to reduce heat and prolong edge life.
• Clear chips frequently on long cuts to prevent recutting and overheating; withdraw the drill and clear obstructed flutes as needed.
• Inspect the drill after heavy usage and re-sharpen before signs of wear become pronounced to maintain hole quality.