When depth, precision, and reliability are non-negotiable in metalworking, the Dormer Pramet A978 4.00 mm HSS-E High Performance Multi-Application Drill is designed to deliver. This straight-shank, extra-long drill blends a precision-built geometry with durable high-speed steel enhanced with cobalt (HSS-E) for demanding materials and long-reach applications.

Why this drill stands out

• 130° point for self-centering — starts cleanly and reduces the push force required to penetrate the workpiece, helping you maintain control and accuracy from the first stroke.
• Bright, contamination-resistant finish — prevents material from sticking to the cutting edge, improving chip flow and reducing fretting on the surface being drilled.
• Parabolic flute design — engineered for drilling extra deep holes in a single pass, minimizing chip clogging and optimizing evacuation in longer holes.
• Premium HSS-E material — enhanced hardness and wear resistance across a range of alloys, including steel, stainless steel, and aluminum, delivering consistent performance over time.
• Extra-long length with straight shank — built for reach where standard drills fall short, ideal for deep cavity work, long-stage bores, and components with limited access.
• DIN 1869 / 3 specification ensures compatibility with standard toolholding and inserts, making integration into existing setups straightforward.

Ideal applications and use cases

Perfect for production runs and workshop tasks that demand deep bores without sacrificing edge life or stability. Suitable for:

• Deep-hole drilling in steel, stainless steel, and aluminum workpieces
• Maintenance and repair tasks where long reach is required to access recessed features
• Automotive, aerospace, and general manufacturing environments where precision and reliability matter

How it performs versus common alternatives

The A978 combines a robust HSS-E core with a geometry optimized for long-hole drilling, offering smoother start, reduced wear, and less chatter compared with standard-length drills. The 130° point and parabolic flute work together to minimize walking and improve chip evacuation in deep holes, resulting in cleaner holes with less secondary operations.

Practical tips for best results

• Use steady, pecking motions to manage heat during deep drilling and to clear chips effectively.
• Apply appropriate cutting fluid or lubrication compatible with the material to extend edge life and reduce built-up edge.
• Secure the workpiece firmly and choose a compatible chuck or collet to minimize runout during the long reach.
• Inspect the drill periodically for wear, especially on the tip and flutes, and replace if signs of dulling appear to prevent poor hole quality.

Engineered for professionals who demand consistent performance through challenging depths, the Dormer Pramet A978 4.00 mm drill is a dependable choice for multi‑material drilling tasks where reach and precision matter.