ISO 6789 is the standard cited for torque wrenches for fastener tightening. This page sets out what the standard controls for this part, reproduces the dimensional table supplied against it, and notes the related designations referenced on drawings.
ISO 6789 — Scope
The table below lists the dimensions catalogued for torque wrenches for fastener tightening under ISO 6789. The scope of ISO 6789 itself is not summarised here — where a figure matters, confirm it against the published document.
Tolerance & Product Grades
Product grade is a concept from dimensional fastener standards and does not apply to ISO 6789. Tolerances for this part are the limits shown against each dimension in the table.
Dimensions Specified by ISO 6789
| Range | Square drive | Typical bolt size at mid-range | Class |
|---|---|---|---|
| 1 – 6 N·m | 1/4 in | M3 – M4 | ISO 6789 click type |
| 5 – 25 N·m | 3/8 in | M5 – M6 | ISO 6789 click type |
| 20 – 100 N·m | 1/2 in | M8 – M10 | ISO 6789 click type |
| 40 – 200 N·m | 1/2 in | M10 – M14 | ISO 6789 click type |
| 70 – 350 N·m | 3/4 in | M16 – M20 | ISO 6789 click type |
| 150 – 750 N·m | 3/4 in | M20 – M24 | ISO 6789 click type |
Companion Standards
A complete specification for torque wrenches for fastener tightening normally cites several documents: one for the geometry, one for the material or mechanical properties, and one for the finish. ISO 6789 is one of them, not all of them.
When to Specify ISO 6789
Choose ISO 6789 for international engineering work and OEM supply where ISO standards are the contractual reference. It is the default modern specification for torque wrenches for fastener tightening.
Custom manufacturing · Made to drawing
Need a fastener tool to this standard in a non-standard size?
Parts built to ISO 6789 are already in the catalog, so a special is usually a variation on existing tooling rather than a new design — which is what keeps the cost down.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
