The Dormer Pramet A400 M3 HSS ST Straight Shank Subland 90 Degree Standard Length drill (DIN 8374) is purpose-built for fast, accurate clearance holes in metric-thread assemblies. With a precise 118-degree pilot and a 90-degree chamfer, it guides clean entry and creates the exact chamfered opening needed for standard metric threads, reducing assembly errors and cross-threading.

Why this drill stands apart

• 118-degree pilot + 90-degree chamfer: Engineered to produce a precise clearance hole with a ready-made chamfer, ensuring easy thread engagement and smoother fastener seating in metric threads.
• Steam oxide finish: A durable, low-friction coating that helps prevent workpiece material from sticking to the cutting edge, improving chip clearance and reducing built-up edge during high-speed drilling.
• Precisely defined pilot diameter and length: Every dimension is chosen to achieve the correct clearance drilling diameter and depth for standard threads, resulting in consistent hole quality across workpieces.
• Premium HSS material: High-speed steel designed for durability across a wide range of materials—including steel, aluminium, and stainless steel—delivering reliable performance in everyday machining and fabrication tasks.
• Straight shank, DIN 8374, standard length (X4D): The straight shank offers universal compatibility with most CNC and conventional machines, ensuring stable, wobble-free operation and easy collet/chuck gripping.
• Versatility for CNC and manual setups: Whether you’re programming a milling center or drilling on a manual machine, this drill maintains precision, reduces tool changes, and supports high-reliability clearance-hole production.

Practical uses and scenarios

Ideal for fabricating chamfered clearance holes in metal plates, panels, and fixture components where metric-threaded fasteners will be installed. Use in assemblies that require a clean chamfer entrance to prevent thread damage, misalignment, or binding as fasteners are threaded in. The A400 M3 drill excels in both routine production runs and precision repair work where reliability and repeatability matter.

Who benefits most

Machinists, fabrication shops, hobbyists, and maintenance technicians who frequently create clearance holes for metric threads will appreciate the predictable hole size, smooth entry, and reduced sticking thanks to the steam oxide finish. It’s particularly well-suited for aluminum and steel workpieces, and it performs well in both CNC milling centers and traditional drill presses.

Tips for best results

• Match the pilot diameter to the target clearance hole size for precise thread assembly.
• Use proper lubrication and moderate cutting speeds to preserve the sharpness of the 118-degree pilot and the 90-degree chamfer edge.
• Begin with a shallow pilot hole if material is particularly hard or prone to work hardening, then progress to the full clearance hole with the same tool.
• Choose a compatible holding method (collet or straight-shank chuck) to maximize stability on both CNC and manual machines.

With its dedicated design for standard metric threads, the Dormer Pramet A400 M3 HSS Straight Shank Subland 90 Degree Standard Length drill offers a reliable, one-tool solution for creating accurate clearance holes and clean chamfer entrances—delivering consistent performance across a range of common machining materials and setups.