The Makita D-30514 is a five-piece HSS drill bit set with a titanium nitride coating, for drilling steel, stainless, aluminium and other metals. The gold TiN layer reduces friction at the cutting edge, which keeps the bit cooler and lets it hold its edge far longer than an uncoated HSS bit of the same size.
What it suits
- Drilling mild steel, sheet metal and box section
- Aluminium profile and bracketry
- Fixing and fabrication work where a plain HSS bit blunts too quickly
Getting the most out of it
Metal drilling rewards slow speed and firm, steady pressure. Run the drill too fast and the heat will take the temper out of the tip no matter what coating it carries. Centre-punch first so the bit does not wander, and use a drop of cutting fluid on anything thicker than sheet.
These are straight-shank bits and fit any keyless or keyed chuck. For masonry you need a masonry or TCT bit instead; for timber, a wood bit will give a cleaner hole.
