Material specification page for compression springs 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 DIN 2098.
Why Choose Grade 12.9 Steel for Compression Springs
The highest common strength class, for high-load machine assembly. For compression springs, 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 compression springs 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 Compression Springs, 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 Compression Springs Available in Grade 12.9 Steel
| Wire dia d (mm) | Inner diameter Di (mm) | Outer diameter De (mm) | Free length Lo (mm) | Active coils n | Rated force Fn (N) | Rate k (N/mm) | Material | Reference standard | Notes |
|---|---|---|---|---|---|---|---|---|---|
| 0.5 | 3.0 | 4.0 | 15 | 8 | 8 | 1.0 | Spring steel SH/DH | DIN 2098 / EN 15800 | Compression spring, ground ends |
| 0.5 | 4.0 | 5.0 | 20 | 10 | 6 | 0.7 | Spring steel SH/DH | DIN 2098 / EN 15800 | Compression spring, ground ends |
| 0.6 | 4.0 | 5.2 | 20 | 9 | 12 | 1.5 | Spring steel SH/DH | DIN 2098 / EN 15800 | Compression spring, ground ends |
| 0.7 | 5.0 | 6.4 | 25 | 10 | 15 | 1.5 | Spring steel SH/DH | DIN 2098 / EN 15800 | Compression spring, ground ends |
| 0.8 | 5.0 | 6.6 | 25 | 10 | 22 | 2.5 | Spring steel SH/DH | DIN 2098 / EN 15800 | Compression spring, ground ends |
| 1.0 | 6.0 | 8.0 | 30 | 10 | 35 | 3.5 | Spring steel SH/DH | DIN 2098 / EN 15800 | Compression spring, ground ends |
| 1.0 | 8.0 | 10.0 | 40 | 12 | 25 | 2.0 | Spring steel SH/DH | DIN 2098 / EN 15800 | Compression spring, ground ends |
| 1.2 | 8.0 | 10.4 | 40 | 10 | 55 | 6.0 | Spring steel SH/DH | DIN 2098 / EN 15800 | Compression spring, ground ends |
| 1.5 | 10.0 | 13.0 | 50 | 10 | 80 | 8.0 | Spring steel SH/DH | DIN 2098 / EN 15800 | Compression spring, ground ends |
| 1.6 | 12.0 | 15.2 | 60 | 10 | 90 | 8.5 | Spring steel SH/DH | DIN 2098 / EN 15800 | Compression spring, ground ends |
| 2.0 | 12.0 | 16.0 | 60 | 10 | 165 | 18.0 | Spring steel SH/DH | DIN 2098 / EN 15800 | Compression spring, ground ends |
| 2.0 | 16.0 | 20.0 | 80 | 12 | 110 | 10.0 | Spring steel SH/DH | DIN 2098 / EN 15800 | Compression spring, ground ends |
| 2.5 | 16.0 | 21.0 | 80 | 10 | 260 | 28.0 | Spring steel SH/DH | DIN 2098 / EN 15800 | Compression spring, ground ends |
| 2.5 | 20.0 | 25.0 | 100 | 12 | 200 | 18.0 | Spring steel SH/DH | DIN 2098 / EN 15800 | Compression spring, ground ends |
| 3.0 | 20.0 | 26.0 | 100 | 10 | 450 | 45.0 | Spring steel SH/DH | DIN 2098 / EN 15800 | Compression spring, ground ends |
| 3.0 | 25.0 | 31.0 | 120 | 12 | 320 | 28.0 | Spring steel SH/DH | DIN 2098 / EN 15800 | Compression spring, ground ends |
| 4.0 | 25.0 | 33.0 | 120 | 10 | 1000 | 90.0 | Spring steel SH/DH | DIN 2098 / EN 15800 | Compression spring, ground ends |
| 4.0 | 30.0 | 38.0 | 150 | 12 | 750 | 65.0 | Spring steel SH/DH | DIN 2098 / EN 15800 | Compression spring, ground ends |
| 5.0 | 30.0 | 40.0 | 150 | 10 | 1900 | 170.0 | Spring steel SH/DH | DIN 2098 / EN 15800 | Compression spring, ground ends |
| 5.0 | 40.0 | 50.0 | 200 | 12 | 1200 | 100.0 | Spring steel SH/DH | DIN 2098 / EN 15800 | Compression spring, ground ends |
| 6.0 | 40.0 | 52.0 | 200 | 10 | 3300 | 280.0 | Spring steel SH/DH | DIN 2098 / EN 15800 | Compression spring, ground ends |
| 6.0 | 50.0 | 62.0 | 250 | 12 | 2100 | 185.0 | Spring steel SH/DH | DIN 2098 / EN 15800 | Compression spring, ground ends |
| 8.0 | 50.0 | 66.0 | 250 | 10 | 7500 | 650.0 | Spring steel SH/DH | DIN 2098 / EN 15800 | Compression spring, ground ends |
| 8.0 | 65.0 | 81.0 | 300 | 12 | 4800 | 430.0 | Spring steel SH/DH | DIN 2098 / EN 15800 | Compression spring, ground ends |
| 10.0 | 65.0 | 85.0 | 300 | 10 | 14500 | 1200.0 | Spring steel SH/DH | DIN 2098 / EN 15800 | Compression spring, ground ends |
| 10.0 | 80.0 | 100.0 | 350 | 12 | 9500 | 800.0 | Spring steel SH/DH | DIN 2098 / EN 15800 | Compression spring, ground ends |