Material specification page for turnbuckle in Grade 12.9 Steel. Covers the grade designation (class 12.9), corrosion and magnetic behavior, comparable grades and their trade-offs, and the sizes available to ISO / DIN.
Why Choose Grade 12.9 Steel for Turnbuckle — ISO / DIN (Series 156)
The highest common strength class, for high-load machine assembly. For turnbuckle — iso / din (series 156), this matters when requires plating or black-oxide protection is the primary requirement.
Mechanical & Physical Properties
| Grade designation | class 12.9 |
|---|---|
| Magnetic response | Magnetic |
| Service temperature | up to approx. +300 °C |
| Corrosion characteristic | Requires plating or black-oxide protection |
Corrosion Behavior in Service
Carbon and alloy steel turnbuckle — iso / din (series 156) require a coating for corrosion protection. Zinc plating (with or without passivation) is the most common; hot-dip galvanizing is used for outdoor structural service; black-oxide is mainly a tarnish-prevention finish for tool-room use.
Comparable Grades
For Turnbuckle — ISO / DIN (Series 156), class 8.8 is the comparable strength step. Move up when the joint preload approaches the proof load of the current class; move down when the joint is over-specified. For corrosion-critical service, switch to stainless A2 or A4.
Sizes of Turnbuckle — ISO / DIN (Series 156) Available in Grade 12.9 Steel
| 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 |