Turnbuckle manufactured to ISO are dimensioned by the size table reproduced on this page. The standard fixes geometry and tolerances only; material and property class are assigned by ISO 898-1/898-2, and surface finish by separate finish standards.
ISO — Scope
ISO specifies the dimensions and tolerances of turnbuckle — iso / din (series 156). 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
ISO, alongside the related ISO / DIN 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 ISO
| Thread size | Total length closed (mm) | Take-up length (mm) | Working load limit (kg) | Material | Reference standard |
|---|---|---|---|---|---|
| M6 | 105 | 75 | 80 | Drop-forged steel, hot-dip galvanized | DIN 1480 / GB/T 5973 |
| M8 | 125 | 90 | 140 | Drop-forged steel, hot-dip galvanized | DIN 1480 / GB/T 5973 |
| M10 | 150 | 110 | 230 | Drop-forged steel, hot-dip galvanized | DIN 1480 / GB/T 5973 |
| M12 | 180 | 135 | 340 | Drop-forged steel, hot-dip galvanized | DIN 1480 / GB/T 5973 |
| M16 | 230 | 170 | 700 | Drop-forged steel, hot-dip galvanized | DIN 1480 / GB/T 5973 |
| M20 | 290 | 215 | 1200 | Drop-forged steel, hot-dip galvanized | DIN 1480 / GB/T 5973 |
| M24 | 355 | 260 | 1800 | Drop-forged steel, hot-dip galvanized | DIN 1480 / GB/T 5973 |
| M30 | 420 | 320 | 3200 | Drop-forged steel, hot-dip galvanized | DIN 1480 / GB/T 5973 |
Companion Standards
ISO controls only the geometry of turnbuckle — iso / din (series 156). 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 ISO
Choose ISO for international engineering work and OEM supply where ISO standards are the contractual reference. It is the default modern specification for turnbuckle — iso / din (series 156).