Dormer Pramet A125 5/16 Inch x 250 mm HSS ST STRAIGHT SHANK EXTRA LONG SERIES DRILL BS 328

Dormer Pramet A125 5/16" x 250 mm HSS Straight Shank Extra Long Drill is engineered for deep-hole precision with a robust, reliable performance across a range of materials. This straight-shank drill bit pairs a 5/16" diameter with a generous 250 mm length, delivering extended reach for demanding drilling tasks without compromising rigidity or accuracy.

Key features that set this drill apart:

• 118-degree conventional point — The sharp, self-centering point starts cleanly on contact and maintains direction with minimal wandering. Even when you’re drilling deep into tough workpieces, this geometry provides a dependable, true start and a straightforward re-grounding process when the edge wears.
• Steam oxide finish — A protective oxide coating minimizes built-up edge and chip adhesion, helping your cutting edge stay clear of gumming and heat buildup. The result is smoother drilling, fewer interruptions, and longer service life between sharpenings.
• Extra long length series — Designed for situations that demand reach, such as deep holes, through-holes in thick materials, or pockets that extend away from the entry surface. The extended flute and shank length give you powerful access where standard drills struggle.
• Premium HSS material — Made from high-speed steel to handle a broad spectrum of common metals, including steel, aluminum, and stainless steel. This versatility makes it a go-to choice for mixed-material machining environments and repair work in workshops and fabrication shops.
• Straight shank, versatile compatibility — The straight shank design ensures compatibility with a wide range of drill chucks and machines, from traditional drill presses to portable hand drills. It’s a reliable, universal choice when you need a consistent, repeatable performance.

Use cases and real-world scenarios where the Dormer Pramet A125 shines:

• Deep-hole drilling in automotive components, fabrications, or structural steel where access is limited and a long reach is essential.
• Through-holes in thick plates or blocks, where a standard-length drill would require multiple setups or flips.
• Prototyping and precision machining on CNC machines or conventional mills that require consistent hole accuracy with minimal walk.
• Material variety environments—switching between steel, aluminum, and stainless steel without changing tools frequently.

Practical guidance for best results:

• Match the speed and feed to the material: moderate speeds for steel, slightly higher feeds for aluminum, and cooled chips for stainless steel to minimize thermal wear.
• Maintain a steady, firm entry to preserve the 118° point geometry; let the drill do the work without forcing it.
• Use proper lubrication or coolant when drilling metals to extend edge life and improve surface finish.
• Inspect the bit after use and re-sharpen as needed to sustain accuracy and cutting efficiency, especially given the long reach where deflection can occur.

Whether you’re outfitting a workshop for general fabrication or tackling a precise deep-hole project, the Dormer Pramet A125 drill delivers reliable performance, consistent results, and extended reach when you need it most.