| Standard Specification for Electrodeposited Coatings of Tin-Lead Alloy | ASTM B-579 | |
| Tin-Lead Alloy Coatings on Steel | ||
| Composition | ||
| Element | Weight, % | |
| Tin (Sn) | 50 to 70 | |
| Lead (Pb) | remainder | |
| Service Condition | Classification Number | Minimum thickness, um |
| SC4a | Fe/SnPb 30 | 30 |
| SC3a | Fe/SnPb 20 | 20 |
| SC2 | Fe/SnPb 10 | 10 |
| SC1 | Fe/SnPb 5 | 5 |
| SC1 | Fe/SnPb 5fb | 5 |
| a: an undercoat of 2.5 um copper is recommended | ||
| b: flow brightened | ||