When Compression Spring — ISO / DIN (Series 144) are required in Grade 12.9 Steel, the alternative grades and the trade-offs between them matter as much as the dimensions. This page covers both, plus mechanical and corrosion data.
Why Choose Grade 12.9 Steel for Compression Spring — ISO / DIN (Series 144)
The highest common strength class, for high-load machine assembly. For compression spring — iso / din (series 144), 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 spring — iso / din (series 144) 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.
Galvanic & Galling Considerations
For compression spring — iso / din (series 144) in steel, the dominant compatibility issue is hydrogen embrittlement at high property classes (10.9 and above) when electroplated. Plating must be followed by an appropriate baking treatment, or a non-electroplated finish (mechanical zinc, zinc flake) should be substituted.
Sizes of Compression Spring — ISO / DIN (Series 144) Available in Grade 12.9 Steel
| Wire dia d (mm) | Outer diameter De (mm) | Free length Lo (mm) | Rate k (N/mm) | Rated force Fn (N) | Material | Reference standard |
|---|---|---|---|---|---|---|
| 0.6 | 5.2 | 20 | 1.5 | 12 | Music wire / chrome silicon | DIN 2098 / GB/T 23934 |
| 0.8 | 6.6 | 25 | 2.5 | 22 | Music wire / chrome silicon | DIN 2098 / GB/T 23934 |
| 1.0 | 8.0 | 30 | 3.5 | 35 | Music wire / chrome silicon | DIN 2098 / GB/T 23934 |
| 1.2 | 10.4 | 40 | 6.0 | 55 | Music wire / chrome silicon | DIN 2098 / GB/T 23934 |
| 1.6 | 15.2 | 60 | 8.5 | 90 | Music wire / chrome silicon | DIN 2098 / GB/T 23934 |
| 2.0 | 20.0 | 80 | 18.0 | 165 | Music wire / chrome silicon | DIN 2098 / GB/T 23934 |
| 2.5 | 25.0 | 100 | 28.0 | 260 | Music wire / chrome silicon | DIN 2098 / GB/T 23934 |
| 3.0 | 30.0 | 120 | 45.0 | 450 | Music wire / chrome silicon | DIN 2098 / GB/T 23934 |
| 4.0 | 40.0 | 150 | 90.0 | 1000 | Music wire / chrome silicon | DIN 2098 / GB/T 23934 |
| 5.0 | 50.0 | 200 | 170 | 1900 | Music wire / chrome silicon | DIN 2098 / GB/T 23934 |