Used primarily for welding similar wrought or cast 25%Cr-20%Ni (310) parent alloys with up to 0.25% carbon. For maximum resistance to solidification cracking and micro fissuring, the Mn version weld metal manganese range is raised to 2-5%. The high alloy content of type 310 gives useful oxidation resistance up to peak temperatures of about 1200°C for heat shields, furnace parts and ducting. These consumables can also be used for mixed welding and dissimilar joints including those where PWHT is applied, but it should be noted that the relatively high thermal expansion coefficient may promote thermal fatigue in transition joints which are subject to thermal cycling. In such cases, nickel base consumables are usually preferred. Other uses include buffer layers and for surfacing. The fully austenitic weld metal can be useful for specialized applications requiring low magnetic permeability (typically <1.01). 310 weld metals are also inherently tough down to –196°C and therefore suitable for cryogenic installations. No preheat required. Preferably keep interpass temperature below 150°C and heat input below 1.5kJ/mm; this is particularly important for high heat input processes e.g. SAW.