When you need Spring Lock Washer — GB/T 5782 / ISO 4014 (Series 003) in the M20 size, the controlling values come from GB/T 5782 / ISO 4014. This page lists them in one place — pitch, head geometry, tool size and the matching hole.
M20 Dimensional Row (GB/T 5782 / ISO 4014)
| For bolt size | Inner diameter d1 (mm) | Outer diameter d2 (mm) | Width b (mm) | Thickness t (mm) | Reference standard |
|---|---|---|---|---|---|
| M20 | 20.2 | 33.6 | 5.5 | 5.0 | GB/T 93 / DIN 127B |
Spanner & Drive for M20 Spring Lock Washer — GB/T 5782 / ISO 4014 (Series 003)
Drive geometry for M20 Spring Lock Washer — GB/T 5782 / ISO 4014 (Series 003) is given by the row above; match the tool to the listed values.
Common Applications for M20 Spring Lock Washer — GB/T 5782 / ISO 4014 (Series 003)
M20 Spring Lock Washer — GB/T 5782 / ISO 4014 (Series 003) are commonly specified for high-load load-spreading on structural joints.
Installation Tips for M20 Spring Lock Washer — GB/T 5782 / ISO 4014 (Series 003)
- At M20 the stretch in the bolt becomes the controlling factor — for critical joints, use angle-controlled or stretch-controlled tightening instead of pure torque.
Mating Parts for M20
A M20 flat washer pairs with a M20 bolt/screw and matching M20 nut.
When to Step Up or Down from M20
When the joint preload approaches the proof load of M20 class 8.8, step up to M24 class 8.8 (or move to M20 class 10.9). When the joint is over-specified, M16 often saves weight and cost without losing the safety margin.