18NiCrMo5 1.6566


1.6566 is a carburizing steel with intermediate case hardenability and medium core hardenability. It is available as hot worked and cold finished bar, rod, and wire; bar subject to end-quench hardenability requirements; and aircraft quality parts



C Si Mn  p s Cr Mo Ni
0.15-0.21 0.15-0.4 0.6-0.9 0.035 0.035 0.7-1 0.15-0.25 1.2-1.5


Hot working:

Forging temperature range: 1200-850℃
Note: Heat to 1200 ℃. Do not forge below 850.
Heat treatment:

Normalizing Annealing Hardening temprature(℃) for quenching in oil Temper Carburizing
900-930 790-850 870-910 570-700 780-820


Main application:

Gear component, bolts, arbors, bushes, coupling boxes high loaded gear parts
Shape of product:

Round, flat, step shape, ring, disc, shaft, other shape depend on customer needs