Meet the Dormer Pramet A125 13.00 mm x 310 mm HSS ST Straight Shank Extra Long Series Drill BS 328—a precision-forged tool built to conquer deep, challenging holes with reliability. This long-reach drill bit is purpose-built for professional workshops where depth and consistency matter, delivering clean starts and steady performance from first contact to the bottom of the hole.

Key advantages at a glance

• 118° conventional point provides a strong, self-centering tip that starts quickly and remains easy to re-grind, helping you maintain accuracy without frequent rework.
• Steam oxide finish minimizes workpiece adherence to the cutting edge, reducing built-up edge and helping ensure smoother drilling across a range of materials.
• Extra long length series is designed for drilling very deep holes and for scenarios where extended reach is essential—ideal for thick stock, internal passages, or components with deep cavities.
• Premium HSS material delivers dependable performance on a variety of materials, including steel, aluminum, and stainless steel, while maintaining sharpness and rigidity over time.
• Straight shank enhances compatibility with a wide range of drill chucks and CNC/FMS setups, offering secure grip and repeatable accuracy.
• BS 328 specification ensures compatibility with standard boring and drilling applications across industries, from fabrication to maintenance.

Designers, machinists, and fabricators rely on this drill for scenarios that demand both reach and performance. The A125’s geometry is optimized for deep-hole drilling in steel and allied metals, but its robust HSS construction also handles aluminum and stainless steel where a steady, straight path is crucial. The result is predictable hole quality, reduced wandering, and dependable chip evacuation even when you’re working far from the chuck.

Why this drill stands out from common options

• Depth without compromise: The extended 310 mm length makes it possible to reach holes that standard bits simply can’t access, reducing the need for hole-splitting approaches or multiple tools.
• Rugged, grindable tip: The 118° point is robust enough to tolerate minor re-grinding between jobs, keeping downtime to a minimum and extending the tool’s useful life.
• Material versatility: While optimized for steel, the HSS composition and steam oxide finish help maintain cutting efficiency across aluminum and stainless steel, enabling a single drill to handle multiple tasks.

Who should consider the Dormer Pramet A125? It’s an excellent choice for workshop environments where deep holes are routine—think automotive fabrication, structural steel work, hydraulic/pneumatic manifolds, and aerospace components with thick walls or internal channels. It’s equally at home on pedestal or CNC drill setups, offering consistent results whether you’re drilling in a precision jig or a rugged production line.

Practical insights to get the most from this drill:

• Use appropriate lubrication or coolant to manage heat buildup during deep-hole drilling, especially in harder steels.
• Maintain a steady feed rate to preserve the 118° tip geometry and prevent premature wear or edge chipping.
• For very deep holes, consider peck drilling routines to clear chips and prevent clogging, which can affect hole quality.
• Inspect the straight shank alignment regularly to ensure a true run in the chuck or spindle, minimizing runout and vibration.

Technical specifications at a glance

• Diameter: 13.00 mm
• Working length / total length: 310 mm (extra long series)
• Shank type: Straight shank
• Tool material: Premium High-Speed Steel (HSS)
• Point angle: 118 degrees (conventional point)
• Finish: Steam oxide
• Standard: BS 328
• Application: Deep-hole drilling in steel, aluminum, stainless steel, and other common metals