The main difference between 35CrMo steel and 30CrMo steel

1.35CrMo steel, refers to the chromium molybdenum alloy steel whose carbon mass fraction is about 0.35%. 30CrMo steel, refers to the the chromium molybdenum alloy steel whose carbon mass fraction is about 0.30%.

2. The carbon content of 35CrMo steel is higher than 30CrMo steel, so 35CrMo steel has better hardness, tensile strength and yield after heat treatment. But 30CrMo steel is better in toughness and low temperature performance, and the difference is relatively small.

3. Chemical elements: 35CrMo steel
C: 0.32~0.40, Si: 0.17~0.37, Mn: 0.40~0.70, S:≤0.035, P:≤0.035, Cr: 0.80~1.10, Ni:≤0.30, Cu:≤0.30, Mo: 0.15~0.25.

30CrMo steel:
C: 0.26~0.34, Si: 0.17~0.37, Mn: 0.40~0.70, r: 0.80~1.10, Mo: 0.15~0.25, P:≤0.035, S:≤0.035, Ni:≤0.030, Cu:≤0.030

4. Temperature Rank: According to the API temperature level classification, 35CrMo steel and 30CrMo steel are often applied to the P-U level, i.e. - 29 (-+121%). However, because of the slightly lower carbon content, 30 CrMo steel is slightly better than 35CrMo steel in low temperature performance.