The M30 size of Tab Lock Washer for Round Nut is dimensioned by GB/T 858. The tables below give the dimensional row from the standard, the drill and spanner sizes that go with it, and the assembly torque per property class. The technical drawing on this page redraws to the exact values selected.
M30 Dimensional Row (GB/T 858)
| For shaft / nut size | Inner diameter d1 (mm) | Outer diameter d2 (mm) | Thickness t (mm) | Tab length (mm) | Reference standard |
|---|---|---|---|---|---|
| M30 | 30.5 | 55 | 1.5 | 16 | GB/T 858 |
Spanner & Drive for M30 Tab Lock Washer for Round Nut — GB/T 858 (Series 073)
Drive geometry for M30 Tab Lock Washer for Round Nut — GB/T 858 (Series 073) is given by the row above; match the tool to the listed values.
Common Applications for M30 Tab Lock Washer for Round Nut — GB/T 858 (Series 073)
M30 Tab Lock Washer for Round Nut — GB/T 858 (Series 073) are commonly specified for high-load load-spreading on structural joints.
Installation Tips for M30 Tab Lock Washer for Round Nut — GB/T 858 (Series 073)
- At M30 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 M30
A M30 flat washer pairs with a M30 bolt/screw and matching M30 nut.

