Here we have some commonly asked questions with our answers or demos. These Quick help links give you some answers but you can still speak to one of our friendly and knowledgeable staff who can give you the answer there and then. Call 0115 978 5454 Monday to Friday 8.00am - 5.00pm
What size drill bit should I use with my self-tapper?
What size drill bit should I use with a Thread Tap?
Bolt Head, thread length and pitch Chart
| Diameter (d) | Pitch | Length of threaded portion* (b) | Head Depth (k) | Across Flats (s) |
|---|---|---|---|---|
| M4 | 0.7mm | 14mm | 2.8mm | 7mm |
| M5 | 0.8mm | 16mm | 3.5mm | 8mm |
| M6 | 1.0mm | 18mm | 4mm | 10mm |
| M7 | 1.0mm | 20mm | 4.8mm | 11mm |
| M8 | 1.25mm | 22mm | 5.3mm | 13mm |
| M10 | 1.5mm | 26mm | 6.4mm | 17mm |
| M12 | 1.75mm | 30mm | 7.5mm | 19mm |
| M14 | 2mm | 14mm | 8.8mm | 22mm |
| M16 | 2mm | 38mm | 10mm | 24mm |
| M18 | 2.5mm | 42mm | 11.5mm | 27mm |
| M20 | 2.5mm | 46mm | 12.5mm | 30mm |
| M22 | 2.5mm | 50mm | 14mm | 32mm |
| M24 | 3.0mm | 54mm | 15mm | 36mm |
| M27 | 3.0mm | 54mm | 15mm | 41mm |
| M30 | 3.5mm | 66mm | 18.7mm | 46mm |
| M33 | 3.5mm | 72mm | 21mm | 50mm |
| M36 | 4mm | 78mm | 22.5mm | 55mm |
| M39 | 4mm | 84mm | 25mm | 60mm |
| M42 | 4.5mm | 90mm | 26mm | 65mm |
| M45 | 4.5mm | 96mm | 28mm | 70mm |
| M48 | 5mm | 102mm | 30mm | 75mm |