Bosch Expert SelfCut Speed Spade Bit 18mm x 152mm

The Bosch Expert SelfCut Speed is a wood spade bit 18mm wide and 152mm long, built for people who drill a lot of holes and would rather not fight the tool to do it. Where a standard flat bit needs you to push hard to keep it moving, the SelfCut uses a self-feeding threaded tip that does exactly what the name says — it pulls itself in. Less effort, more holes, and you can get on with the actual job.

The 18mm diameter is one of the most commonly needed sizes on site. It clears a 20mm conduit with a bit of give, handles common cable runs, and fits standard door handle back plates — the kind of size you reach for so often it ends up living in your drill bag permanently. At 152mm total length it has enough reach for standard timber framing and joinery without being so long it becomes awkward in tighter spaces.

What Makes the Bosch Expert SelfCut Different From a Basic Spade Bit

The obvious answer is the tip. The self-feeding thread means the bit tracks straight and pulls cleanly through the cut rather than wandering under pressure. That matters when you are drilling at an angle through a stud wall with a cable running behind it and nowhere to reposition. The wave-shaped spade profile helps clear chips as you go, which keeps the bit from binding up mid-hole — something that happens more than it should with cheaper alternatives, particularly in damp or resinous timber.

The 1/4 inch hex shank is standard for spade bits and fits both three-jaw and hex chuck drill drivers without adapters. Straightforward. Bosch makes these from high-quality steel, and the Expert range sits above the standard line — you notice it after a few dozen holes when a cheaper bit would already be wandering.

These wood spade bits are the go-to for electricians pulling cables through floor joists, carpenters fitting door furniture, and plumbers running pipe through stud walls. If you need a clean 18mm hole quickly and repeatedly, this is a sensible bit to carry.