Grade 12.9 Steel (class 12.9) is the highest common strength class, for high-load machine assembly. When specialty nails are specified in this grade, the dimensions remain per Industry standard; the material determines corrosion behavior (requires plating or black-oxide protection) and the service temperature range (up to approx. +300 °C). Both are covered below with the size table.
Why Choose Grade 12.9 Steel for Specialty Nails
The highest common strength class, for high-load machine assembly. For specialty nails, 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 |
Galvanic & Galling Considerations
For specialty nails 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.
Comparable Grades
For Specialty Nails, 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 Specialty Nails Available in Grade 12.9 Steel
| Nail type | Diameter (mm) | Common length range (mm) | Head diameter (mm) | Point form | Application | Reference standard |
|---|---|---|---|---|---|---|
| Round steel nail | 1.8 | 32~65 | 4.5 | Pointed | General woodworking | DIN 1151 |
| Round steel nail | 2.5 | 45~90 | 6.5 | Pointed | General woodworking | DIN 1151 |
| Round steel nail | 3.1 | 60~120 | 7.5 | Pointed | Structural woodworking | DIN 1151 |
| Round steel nail | 3.8 | 80~150 | 9.5 | Pointed | Structural woodworking | DIN 1151 |
| Spiral nail | 2.5 | 45~90 | 5.5 | Pointed | Pallet / crate | Industry standard |
| Spiral nail | 3.1 | 60~120 | 7.5 | Pointed | Pallet / crate | Industry standard |
| Ring-shank nail | 2.5 | 45~75 | 6.5 | Pointed | Pull-out resistant | DIN 1052 |
| Ring-shank nail | 3.1 | 60~100 | 7.5 | Pointed | Pull-out resistant | DIN 1052 |
| Concrete steel nail | 2.5 | 20~50 | 5.5 | Hardened taper | Concrete / masonry | Industry standard |
| Concrete steel nail | 3.0 | 30~60 | 6.5 | Hardened taper | Concrete / masonry | Industry standard |
| Pneumatic nail | 1.6 | 15~50 | 3.0 | D-head | For nail gun | Industry standard |
| Pneumatic nail | 2.0 | 25~65 | 3.5 | D-head | For nail gun | Industry standard |
| Staple | 1.4 | 10~20 | - | Double-pointed | Cable / hose fixing | Industry standard |
| Staple | 1.8 | 14~25 | - | Double-pointed | Cable / hose fixing | Industry standard |
| Staple | 2.0 | 16~32 | - | Double-pointed | Cable / hose fixing | Industry standard |