M20×2 thread: 20 × 2 mm
Threads › M20×2
M20×2 is an ISO metric fine thread: 20 mm major diameter, 2 mm pitch, 60° form. Clearance hole 21 mm (close) or 22 mm (normal).
| Standard | ISO metric fine |
|---|---|
| Major diameter | 20 mm |
| Pitch | 2 mm |
| Thread angle | 60° |
| Minor diameter, bolt | 17.55 mm |
| Minor diameter, nut | 17.83 mm |
| Tap drill | Not listed. Check your tap maker's chart. |
| Clearance hole | 21 mm close, 22 mm normal |
| Usual class | 6g bolt, 6H nut |
Minor diameters worked out from the basic profile: major Ø − 1.22687 × pitch (bolt) and − 1.08253 × pitch (nut).
Open M20×2 in BenchsmithAdd to order list
What the call-out means
M | ISO metric |
20 | Major diameter, mm |
× 2 | Pitch, mm. Given because it is a fine pitch |
-6g | Bolt tolerance class (usual) |
-6H | Nut tolerance class (usual) |
Measure it
Bolt: Measure across the crests of the bolt with the caliper jaws. Worn bolts read 0.1 to 0.3 under.
Nut or tapped hole: Measure across the tops of the threads inside the nut or hole with the inside jaws. That is the minor Ø. Worn or oversize holes read a little over.
Same diameter, other pitch
Close in size, won't mate
- Tr20×4Ø20 mm, 4 mm pitch
- 3/4-10 UNCØ19.05 mm, 10 TPI
- 3/4-16 UNFØ19.05 mm, 16 TPI
- 3/4 BSWØ19.05 mm, 10 TPI
- 3/4-6 ACMEØ19.05 mm, 6 TPI
- G1/2Ø20.96 mm, 14 TPI
One size up or down
Got a bolt and no idea what it is? Measure the outside Ø and type it into Benchsmith → Find → Thread.