HSS Roll Forged Imperial Drill Bits – Pk

HSS roll forged imperial drill bits are a straightforward workhorse for anyone who still works in inches. Whether you’re drilling clearance holes for imperial fixings, working on older steelwork with imperial specifications, or just matching a thread tap size chart that dates back to before metrication, these cover the ground. The 135° split point is the detail that earns its keep here — it bites into the material immediately rather than skating around looking for purchase, which means faster penetration and less wander on the initial entry.

Roll forging is worth understanding if you haven’t thought about it before. The process compresses and aligns the grain structure of the steel rather than cutting through it, which gives a stronger, tougher bit than a ground-only alternative at the same price point. That matters when you’re drilling repetitively or pushing through harder non-alloy steels where a weaker bit would flex and drift. These are HSS steel throughout, which handles the heat generated in steel, cast iron, aluminium, wood, and most plastics without losing the edge too quickly.

Where HSS Roll Forged Imperial Drill Bits Work Best

The black oxide finish does a couple of useful things. It reduces surface friction slightly, which helps with chip evacuation, and it gives a degree of corrosion resistance for storage and general site use. It’s not a coating designed for extreme conditions, but it’s practical for trade use and beats bare bright steel when the bits end up rattling around in a damp toolbox over winter.

These are available in a range of imperial fractional sizes and come in packs of five or ten depending on the size, which makes it sensible to keep multiples of the sizes you use most. Running a drill bit to destruction and having to stop a job to find a replacement is nobody’s idea of productive. The DIN338 standard means the geometry and tolerances are consistent across the range, so you can trust the sizing when you’re matching to tapped holes or reaming to fit.