T 858 is the governing dimensional standard for tab lock washer for round nut. This page sets out the scope of the standard, reproduces the full size table it specifies, and lists the DIN/ISO/ASME cross-references commonly cited in datasheets and drawings.
T 858 — Scope
T 858 specifies the dimensions and tolerances of tab lock washer for round nut — gb/t 858 (series 089). Material, property class, surface finish and packaging are governed by separate documents in the same standards family (for example ISO 898-1 for the mechanical property classes of bolts and screws).
Tolerance & Product Grades
T 858, alongside the related GB/T 858 entries on this site, specifies product grades (typically A or B for fine work and C for general engineering) and tolerance classes for the controlling dimensions. Choose the grade against the precision your application requires.
Dimensions Specified by T 858
| For shaft / nut size | Inner diameter d1 (mm) | Outer diameter d2 (mm) | Thickness t (mm) | Tab length (mm) | Reference standard |
|---|---|---|---|---|---|
| M10 | 10.5 | 21 | 1.0 | 8 | GB/T 858 |
| M12 | 12.5 | 25 | 1.0 | 9 | GB/T 858 |
| M16 | 16.5 | 30 | 1.0 | 10 | GB/T 858 |
| M20 | 20.5 | 38 | 1.5 | 12 | GB/T 858 |
| M24 | 24.5 | 45 | 1.5 | 14 | GB/T 858 |
| M30 | 30.5 | 55 | 1.5 | 16 | GB/T 858 |
| M36 | 36.5 | 65 | 2.0 | 18 | GB/T 858 |
| M48 | 48.5 | 85 | 2.0 | 20 | GB/T 858 |
| M60 | 60.5 | 105 | 2.5 | 24 | GB/T 858 |
Companion Standards
T 858 controls only the geometry of tab lock washer for round nut — gb/t 858 (series 089). The mechanical strength is set by ISO 898-1 (bolts and screws) or ISO 898-2 (nuts); the surface finish is governed by separate finish standards (e.g. ISO 4042 for electroplating). For corrosion testing, the relevant document is ISO 9227 (neutral salt spray).
When to Specify T 858
Choose T 858 for international engineering work and OEM supply where ISO standards are the contractual reference. It is the default modern specification for tab lock washer for round nut — gb/t 858 (series 089).