Material specification page for spring (roll) pins 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 8748 / DIN 1481.
Why Choose Grade 12.9 Steel for Spring (Roll) Pins
The highest common strength class, for high-load machine assembly. For spring (roll) pins, 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 spring (roll) pins 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 Spring (Roll) Pins, 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 Spring (Roll) Pins Available in Grade 12.9 Steel
| Nominal diameter (mm) | Recommended hole (mm) | Common length range (mm) | End chamfer (mm) | Material | Reference standard |
|---|---|---|---|---|---|
| 1.0 | 1.0 | 4~10 | 0.3 | Spring steel | ISO 8748 / DIN 1481 |
| 1.2 | 1.2 | 4~12 | 0.3 | Spring steel | ISO 8748 / DIN 1481 |
| 1.5 | 1.5 | 4~16 | 0.3 | Spring steel | ISO 8748 / DIN 1481 |
| 2.0 | 2.0 | 6~20 | 0.5 | Spring steel | ISO 8748 / DIN 1481 |
| 2.5 | 2.5 | 6~24 | 0.5 | Spring steel | ISO 8748 / DIN 1481 |
| 3.0 | 3.0 | 8~30 | 0.5 | Spring steel | ISO 8748 / DIN 1481 |
| 4.0 | 4.0 | 8~40 | 0.8 | Spring steel | ISO 8748 / DIN 1481 |
| 5.0 | 5.0 | 10~50 | 0.8 | Spring steel | ISO 8748 / DIN 1481 |
| 6.0 | 6.0 | 12~60 | 1.0 | Spring steel | ISO 8748 / DIN 1481 |
| 8.0 | 8.0 | 16~80 | 1.0 | Spring steel | ISO 8748 / DIN 1481 |
| 10.0 | 10.0 | 20~100 | 1.5 | Spring steel | ISO 8748 / DIN 1481 |
| 12.0 | 12.0 | 25~120 | 1.5 | Spring steel | ISO 8748 / DIN 1481 |
| 13.0 | 13.0 | 25~120 | 1.5 | Spring steel | ISO 8748 / DIN 1481 |
| 14.0 | 14.0 | 30~160 | 2.0 | Spring steel | ISO 8748 / DIN 1481 |
| 16.0 | 16.0 | 30~160 | 2.0 | Spring steel | ISO 8748 / DIN 1481 |
| 20.0 | 20.0 | 40~200 | 2.0 | Spring steel | ISO 8748 / DIN 1481 |