Dormer Pramet A125 1/4 Inch x 250 mm HSS ST STRAIGHT SHANK EXTRA LONG SERIES DRILL BS 328

Meet the Dormer Pramet A125 1/4 inch x 250 mm HSS straight shank extra long drill — a purpose-built solution for deep-hole drilling that fits standard chucks and drills. This is not a generic long drill; it’s designed to reach into tight or recessed areas with reliability and consistency.

Key features that matter in real-world work: the 118° conventional point delivers a strong, self-centering start that’s easy to re-grind, reducing downtime between holes. The steam oxide (steam tempered) finish helps minimize galling and prevents workpiece material from sticking to the cutting edge, improving chip flow and reducing drag in stainless steel, aluminum, and steel. The straight shank and BS 328 specification ensure compatibility with a wide range of machines and chucks, from manual drill presses to CNC setups.

• Diameter: 1/4" (6.35 mm); Overall length: 250 mm; Flute length: 200 mm
• Point: 118° conventional point for robust entry and easy regrinding
• Material: Premium HSS for versatile work across steel, aluminum, and stainless steel
• Finish: Steam oxide (tempered) to reduce sticking and improve edge durability
• Shank: Straight cylindrical shank for broad compatibility with common chucks
• Depth capability: Designed for deep holes with up to 10xD single-pass drilling without pecking
• Standard: BS 328 compliant for consistent sizing and performance

Who benefits most: professionals and hobbyists tackling long through-holes, deep cavities, or recessed features where a standard drill simply won’t reach. Ideal applications include structural steel sections, automotive components, machinery housings, and long aluminum profiles where reliable reach and clean entry matter. This drill excels when you need a single tool that combines depth, rigidity, and precision without frequent tool changes.

Practical tips for optimal results: use a steady feed and appropriate cutting fluid to maintain a clean cut, especially in harder materials. Start with a light pilot to help alignment, then advance smoothly to avoid deflection. If the point dulls, regrind carefully to restore the 118° geometry, and store the drill dry to prevent corrosion on the steam-oxide finish. For best depth performance, trust it for up to 10xD in a single pass, as specified for the A125 series.