Specification 1. Chromium molybdenum alloy steel . 2. Slightly higher carbon content then 4130. 3. Greater strength and heat treatment. Application 1. Applications in the oil and gas sector. 2. Connection rods, collets, conveyor pins. 3. Gears, stem assemblies. 4. Pump shafts and tool holders. Chemical composition C Si Mn P S Cr Mo 0.38~0.45 0.17~0.37 0.50~0.8 â?¤0. â?¤0. 0.9~1.2 0.15-0.25 Similar grade GB AISI/ASTM DIN JIS 42CrMo 4140 1.7225 SCM44