Product Overview
SN-220 Tempering Salt is a medium-temperature nitrate/nitrite salt bath compound with a working range of 220°C–550°C. It covers three distinct heat treatment processes: martempering (medium-carbon and alloy steels), austempering (ductile and grey cast iron), and the secondary hardening / tempering cycle of HSS cutting tools after high-temperature hardening.
The higher minimum temperature (220°C vs. SN-140's 150°C) makes SN-220 the preferred bath for spring steels, alloy die steels and auto components where the target tempering temperature falls in the 300°C–500°C range — and for HSS secondary hardening where peak performance requires precise tempering at 540°C–560°C.
Technical Specifications
| Product Code | SN-220 |
| Salt Type | Nitrate/nitrite medium-temperature quench salt |
| Working Temperature | 220°C – 550°C |
| Processes Covered | Martempering · Austempering · HSS secondary tempering |
| Physical Form | Granular salt blend |
| Packaging | 25 kg HDPE sealed bags |
| Compatible Steel Grades | Spring steels, H13, D2, M2/M35 HSS, ductile iron |
| HSS Tempering Cycle | 3× tempers at 540°C–560°C (secondary hardening) |
| Storage | Cool, dry — segregate from combustibles |
| Documentation | COA, MSDS, TDS included with every order |