Dormer Pramet A125 10.50 mm x 400 mm HSS ST STRAIGHT SHANK EXTRA LONG SERIES DRILL BS 328

Meet the Dormer Pramet A125 10.50 mm x 400 mm HSS ST Straight Shank Extra Long Series Drill BS 328—the long-reach solution engineered for deep-hole precision in a range of metals. Built for demanding workshops and busy fabrication floors, this drill combines a robust tip geometry with a tough high-speed steel core to deliver reliable performance where others fall short.

Why this drill stands out

• 118-degree conventional point — a strong, easily re-grindable tip that maintains alignment through stubborn workpieces and minimizes wandering when starting a hole.
• Steam oxide finish — a low-friction surface that helps chips shed smoothly and reduces material sticking to the cutting edge, extending tool life and improving hole quality.
• Extra long length (400 mm) — designed for drilling very deep holes and accessing recessed areas or thick workpieces without needing extensions or multiple tools.
• Premium HSS material — versatile enough to tackle steel, aluminum, and stainless steel with consistent performance and maintained edge life under typical production conditions.
• Straight shank — compatible with a wide range of chuck types and machines, delivering precise centering and steady torque transfer for clean, straight holes.

Practical use cases

Ideal for automotive fabrication, metal fabrication shops, maintenance and repair tasks, and CNC or conventional drilling setups. When you need to bore deep through thick plates, hollow sections, or structural components, this drill’s extended reach helps you avoid dismantling assemblies just to access the hole location. It’s equally effective for drilling through-access holes in extrusions, housings, and machinery frames where space is limited and hole depth is critical.

How it helps your workflow

With the A125’s precise geometry and durable HSS core, you’ll experience consistent hole quality from the first pass to the last. The 10.50 mm diameter provides a reliable size tolerance for fits and fasteners, while the 400 mm length reduces setup time by eliminating the need for multiple shorter drills or extensions. This translates to faster cycle times, fewer tool changes, and improved overall shop efficiency.

Tips for best results

• Use a suitable coolant or cutting fluid to manage heat during deep hole drilling and to extend tool life.
• Start with a light pilot hole if material hardness or a tight tolerance is required, then progress to the full diameter for clean entry.
• Securely clamp the workpiece and maintain steady feed pressure to avoid deflection, especially in longer drills.
• Inspect the flute for chips and clear them regularly to maintain smooth cutting action.