精密钢管常用规格|精密钢管允许尺寸偏差
　　10# 0.07~0.13 0.17~0.37 0.35~0.65 ≤0.035 ≤0.035 
　　20# 0.17~0.23 0.17~0.37 0.35~0.65 ≤0.035 ≤0.035 
　　35# 0.32~0.39 0.17~0.37 0.35~0.65 ≤0.035 ≤0.035 
　　45# 0.42~0.50 0.17~0.37 0.50~0.80 ≤0.035 ≤0.035 
　　40cr 0.37~0.44 0.17~0.37 0.50~0.80 ≤0.035 ≤0.035 0.08~1.10 
　　25Mn 0.22~0.2 0.17~0.37 0.70~1.00 ≤0.035 ≤0.035 ≤0.25 
　　37Mn5 0.30~0.39 0.15~0.30 1.20~1.50 ≤0.015 ≤0.020