Dormer Pramet A125 5/8 Inch x 310 mm HSS ST STRAIGHT SHANK EXTRA LONG SERIES DRILL BS 328

The Dormer Pramet A125 5/8 Inch x 310 mm HSS Straight Shank Extra Long Series Drill is engineered for deep-hole precision without compromising versatility. This premium HSS twist drill bit combines an extended reach with robust construction, making it the go-to choice when depth and accuracy matter in metalworking, fabrication, and maintenance tasks.

Why this drill stands out

Extra-long reach for deep holes — At 310 mm in length, this A125 drill delivers the extended reach you need to access hard-to-reach recesses, through-thick workpieces, and deep bores. The straight shank ensures a solid, true bite and compatibility with a wide range of drilling machines and chucks, from CNCs to portable drills.

Precise, reliable starting with an 118-degree point — The conventional 118° point design creates a strong, self-centering starting tip that resists wandering. This makes it easier to start holes cleanly on tough materials, reducing the need for retouching feeds and exits, and enabling consistent hole positioning even in challenging setups.

Steam oxide finish for smoother cutting and easier part removal — The oxide coating minimizes friction between the cutting edge and the workpiece, helping chips flow more readily and reducing workpiece sticking during drilling. The result is smoother drilling, less heat buildup, and longer edge life in a variety of metals.

Premium HSS material for broad material compatibility — Made from high-speed steel, this drill bit is designed to handle steel, aluminum, and stainless steel with reliable performance. It’s a versatile tool for shops that encounter mixed-material projects, from automotive to industrial maintenance and light fabrication.

BS 328 specification backed by Dormer Pramet quality — The A125 series is built to meet exacting standards, offering durable geometry, consistent drill diameters, and dependable performance across repeat jobs. This makes it ideal for technicians who tackle recurring deep-hole tasks and demand consistency from one job to the next.

Specifically useful in real-world scenarios

Perfect for drilling deep blind or through-holes in thick steel plates, structural components, or panels where standard-length bits fall short. It’s equally at home in fabricating racks, frames, or assemblies that require precise centering and clean bore exits. The combination of a 5/8 in diameter and 310 mm length balances aggressive material removal with controlled accuracy, enabling you to progress quickly without sacrificing hole quality.

What you gain with this drill

• Improved depth capability for challenging projects without changing tooling mid-task
• Reduced wandering at the start thanks to the 118° point, saving time on setup
• Less workpiece adhesion due to steam oxide finish, facilitating faster chip clearance
• Broad material reach with reliable performance on steel, aluminum, and stainless steel
• Solid chuck engagement and compatibility across common drilling machines thanks to the straight shank

Practical use tips

For best results, pair the drill with appropriate cutting fluid or coolant to manage heat on harder materials, and select a spindle speed that matches the material and diameter to maintain a sharp cutting edge. Secure the workpiece firmly to prevent deflection, and consider a pilot hole when drilling particularly thick or hard sections to guide the bit and extend its life.

Whether you’re implementing a deep-hole drilling operation in metal fabrication, performing maintenance on machinery, or tackling a precise, high-depth bore in stainless steel, the Dormer Pramet A125 5/8 Inch x 310 mm HSS Straight Shank Extra Long Series Drill BS 328 is built to deliver dependable performance, depth, and control.