Dormer Pramet A125 12.00 mm x 310 mm HSS ST STRAIGHT SHANK EXTRA LONG SERIES DRILL BS 328

Meet the Dormer Pramet A125 12.00 mm x 310 mm HSS extra-long drill—a purpose-built solution for deep-hole drilling that professionals trust. This straight-shank twist drill is designed to reach into tight spaces and bore clean, accurate holes in a variety of metals without frequent re‑setup.

Why this A125 stands out

• Extended reach for deep holes: As an extra-long series drill, it delivers significant length (310 mm overall with a 250 mm flute) to access recessed areas and multi-pass work without repositioning your setup. This makes it ideal for automotive, fabrication, and structural projects where depth matters.
• 118° conical point for quick starts: The 118° point enhances self-centering and reduces wandering, letting you start holes reliably and maintain accuracy through the cut. The edge is easy to re‑grind when sharpening is needed.
• Steam oxide finish for smoother cutting: The steam oxide surface improves lubricity and helps chips evacuate, reducing friction on the cutting edge and helping to keep materials from sticking during the cut.
• Premium HSS material for versatility: Made from high‑speed steel, this drill handles a wide range of materials—from standard steel and alloy steel to aluminum and copper, making it a flexible choice for mixed‑material workpieces.
• Straight shank for compatibility: A true straight shank (ST) design ensures robust grip and consistent torque transfer in a variety of drilling machines, from benchtop drills to CNC setups.
• BS 328 standard compliance: The A125 series adheres to the BS 328 specification, ensuring consistent geometry and interchangeability with other standard drills in professional shops.

What problems it solves

• Eliminates frequent re‑centerings and pecking when drilling deep holes, thanks to its long flute length and rigid straight shank.
• Delivers dependable hole starts in steel and non‑ferrous materials, thanks to the precise 118° point and steam oxide finishing.
• Reduces tool changes in multi‑stage projects by covering a broad material spectrum with a single, reliable drill bit.

Ideal for

• Metal fabrication, automotive repair, and construction where deep, straight-through holes are needed.
• Workholding setups and pillar or CNC machines that require long reach without sacrificing rigidity.
• Situations demanding a single-pass or minimal‑peck drilling approach in steel, aluminum, and similar alloys.

Technical specifications at a glance

• Diameter: 12.00 mm
• Overall length: 310 mm
• Flute length: 250 mm
• Point angle: 118°
• Shank: Straight
• Material: High-Speed Steel (HSS)
• Finish: Steam oxide
• Standards: BS 328
• Number of flutes: 2
• Recommended depth per pass: up to 10xD in a single pass for steel applications

When you need reliable, high‑performance drilling that combines reach, versatility, and durability, the Dormer Pramet A125 12.00 mm x 310 mm HSS extra-long drill is a practical choice for pro shops and serious hobbyists alike. Its robust construction, matched with BS 328 compliance and a finish that minimizes sticking, helps you push deeper with confidence and finish holes that meet exacting standards.

Used correctly with compatible equipment, this drill supports clean starts, precise hole locations, and consistent hole diameters across a range of common metals.