标准	牌号	化学成份%
		碳	硅	锰	硫	磷	铬
		C	Si	Mn	S	P	Cr
GB/T699     GB/T3639-2000     GB3077-88	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