Nuts and bolts
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Hello everyone! How can one distinguish between high-temperature and low-temperature nuts and bolts?
High-temperature nuts should be marked with CYMO; ordinary ones have no markings
How can nuts and bolts be distinguished as being for high-temperature or low-temperature use? Their materials differ. High-temperature and high-pressure bolts are suitable for steam and petroleum products at a nominal pressure of PN≤17.0 MPA and a temperature of ≤570°C. Common grades include alloy steels such as 25CrMoV, 25Cr2MoV, 25Cr2Mo1V, 40Cr, 40CrNi, 35CrMoA, etc. The specific selection must be made in accordance with the requirements of the pressure and temperature specifications. Low-temperature bolts, suitable for media such as ethylene, propylene, liquefied natural gas, and liquid nitrogen at a nominal pressure of PN≤6.4 Mpa and temperatures of ≥–196°C. Common grades include 304, 0Cr18Ni9, 1Cr18Ni9Ti