STTC-, SMTC-Solder Tip Cartridges are the standard soldering tip range for the Metcal MX-500, MX-5200 and MX-5200 series soldering systems. All cartridges are available in 3 temperature ranges, 600-series nominally 330 Deg C, 700-series nominally 390 Deg C and 800-series nominally 450 Deg C.  The temperature/series is designated by the first digit following the dash in the part number. e.g. 600-series is STTC/SMTC-0xxx, 700-series is STTC/SMTC-1xxx and 800-series is STTC/SMTC-8xxx. Metcal recommends the 700-series for the majority of applications. The 600-series for light load or low temperature applications, 800-series for high temperature and thermally demanding applications. Can be used with leaded and lead-free solder. The Metcal "SmartHeat-Technology" automatically adjusts power levels during each soldering operation.