Meet the Dormer Pramet A125 7/16 inch x 310 mm HSS straight shank extra-long drill — a purpose-built solution for deep-hole precision in metalworking. When reach matters as much as rigidity, this drill balances a robust cutting edge with long-form geometry designed to access tight or recessed workpieces without needing extra extensions.

Why the A125 excels for deep drilling

The A125 features a conventional 118-degree point, engineered to establish a strong, self-centering starting cut. This geometry makes it easier to re-grind if you ever need a touch-up in the workshop, reducing downtime and keeping production moving. The steam oxide finish minimizes workpiece material adhesion to the cutting edge, helping chips break away cleanly and reducing built-up edge during sustained drilling runs.

Long-form design for maximum reach

As an extra-long series drill, this tool is purposefully sized for drilling very deep holes or when access is restricted. The 310 mm overall length provides substantial reach with a rigid straight shank, enabling consistent hole locations, concentricity, and accurate depth control across thick plates and complex assemblies. It’s a dependable choice when a standard-length drill would require added setup and accessory handling.

Premium HSS material for versatility

Made from high-speed steel, the A125 handles a broad spectrum of metals, including carbon steel, alloy steel, aluminum, and stainless steel. Its robust composition delivers dependable performance across everyday fabrication tasks, prototype work, and production runs alike. The straight shank ensures compatibility with a wide range of chucks and collets, making tool changeovers straightforward and quick.

What this drill delivers in real-world use

• Deep holes with reliable symmetry: The 7/16" diameter paired with a precise 118° tip creates clean, round holes with minimal wandering, ideal for fasteners, bushings, or pass-through features.
• Reduced sticking and smoother chips: Steam oxide finish minimizes friction and material adhesion, helping chips evacuate more freely even in longer drilling cycles.
• Consistent performance across materials: From steel to aluminum and stainless, you’ll experience predictable cutting action, straightforward deburring, and clean hole finishes.
• Operational efficiency: The extended length reduces the need for secondary tools or adapters, speeding up setups on busy machine cells or job shops.
• Durable, regrind-ready geometry: The sharp 118-degree point is designed to be resharpened, extending tool life and keeping cutting forces manageable through multiple workpieces.

Ideal applications and who benefits most

This Dormer Pramet A125 drill is perfectly suited for machine shops, maintenance facilities, and fabrication environments where deep-hole drilling is routine. It’s especially advantageous for:

• Deep holes in automotive benchmarks, hydraulic blocks, or engine components where access isn’t forgiving.
• Fabrication or assembly work involving thick metal plates where a standard-length drill would require extra handling.
• Prototyping or low-volume production that demands quick changes and reliable hole quality without custom tooling.

Practical tips for best results

To maximize performance with the Dormer Pramet A125:

• Use appropriate cutting fluid to cool and lubricate the drill, especially on stainless steel or high-strength alloys.
• Begin with a light pilot cut if the workpiece is hard or plates are prone to grabbing, then advance to full-depth drilling.
• Maintain steady feed pressure and avoid high drilling speeds that can lead to overheating, particularly on longer drill cycles.
• Check alignment frequently when working with deeply recessed features to preserve hole concentricity.
• Inspect the tip after multiple uses and regrind as needed to preserve the 118-degree geometry for consistent starts.

Durability and compatibility

With its premium HSS construction and straight shank, this drill is compatible with a broad range of machine tools and spindle setups. The extra-long design doesn’t just reach; it maintains rigidity through deeper cuts, helping you avoid deflection and chatter that can compromise hole quality.

In summary

The Dormer Pramet A125 7/16 inch x 310 mm HSS straight shank extra-long series drill BS 328 is a dedicated tool for deep-hole drilling with dependable edge retention, easy re-sharpening, and versatile material capability. It’s the go-to choice when your project demands maximum reach without sacrificing edge clarity or performance in steel, aluminum, or stainless applications.