Timber rough-ins move fast when the drill bit matches the pipe on the first hole, and slow down badly when it doesn't. The Plumtool Timber Rough-In Boring Kit (PTKIT-BORE) is the 4-piece Rapid Bore set plus the extension bar to reach the holes a standard-length bit can't.
What's in the kit
- Rapid Bore Kit, 4-piece self-clearing wood drill set, 25-57mm (PTRB985)
- Extension Bar to suit Rapid Bore bits and hole saws, 140mm (PTEB537)
Matching bore size to pipe
The four bits in the Rapid Bore set step through 25mm, 32mm and 57mm (sold individually as PTRB686, PTRZ7746 and PTRB685), each self-clearing so the bit doesn't pack with swarf and bind halfway through a joist or stud. As a rough guide: 25mm suits 20mm copper or PEX with clearance, 32mm suits 25mm pipe or a tighter 20mm run, and 57mm is sized for 50mm PVC pipe — the common DWV branch size. If you want the individual bit specs and pricing rather than the kit, see our Rapid Bore sizing guide.
Why the extension bar is in the kit, not optional
A standard-length spade or auger bit runs out of reach drilling through a deep wall plate, a double joist, or anywhere you can't get the drill body close to the timber. The 140mm extension bar fits both the Rapid Bore bits and 7/16in hole saw arbors, so it's doing double duty if you're also running a hole saw on the same job — not a Rapid-Bore-only accessory.
Kit price vs buying separately
The 4-piece bit set and the extension bar bought separately come to $410.90 ($372.75 for the Rapid Bore kit, $38.15 for the extension bar). The kit here is $369.81, a genuine 10% saving. It's worth buying as a kit if you don't already own an extension bar — if you do, the Rapid Bore 4-piece set on its own covers the bit side.
Frequently Asked Questions
What pipe sizes do the 25mm, 32mm and 57mm bits suit?
Roughly: 25mm for 20mm copper or PEX with clearance, 32mm for 25mm pipe or a tighter 20mm run, and 57mm for 50mm PVC DWV pipe — always check clearance against the actual pipe and any insulation or lagging before committing to a size.
Does the extension bar only work with Rapid Bore bits?
No — it also fits 7/16in hole saw arbors, so it's useful on any deep-reach drilling job, not just timber boring with the Rapid Bore set.
Why is the bit set described as self-clearing?
The flute design on each bit is built to clear timber swarf as it cuts, rather than packing the bit and binding or burning in a deep hole — which is what causes a standard bit to bind or smoke in thick framing.
How much does the kit save over buying the bit set and extension bar separately?
$41.09 — $410.90 bought individually against $369.81 for the kit.