UNI EN 10263-4:2003
Tipi di acciaio, composizione chimica (analisi di colata)
				Composizione chimica
Designazione dell'acciaio                                     (in% di massa)
Simbolica	Numerica	C	Si	Mn	P	S	Cr	Mo	Cu	B
					max	max			max
23B2	1.5508	0.20/0.25	0.30 max	0.60/0.90	0.025	0.025	0.30 max		0.25	0,0008/0,005
28B2	1.5510	0.25/0.30	0.30 max	0.60/0.90	0.025	0.025	0.30 max		0.25	0,0008/0,005
33B2	1.5514	0.30/0.35	0.30 max	0.60/0.90	0.025	0.025	0.30 max		0.25	0,0008/0,005
38B2	1.5515	0.35/0.40	0.15/0.30	0.60/0.90	0.025	0.025	0.30 max		0.25	0,0008/0,005
17MnB4	1.5520	0.15/0.20	0.30 max	0.90/1.20	0.025	0.025	0.30 max		0.25	0,0008/0,005
20MnB4	1.5525	0.18/0.23	0.30 max	0.90/1.20	0.025	0.025	0.30 max		0.25	0,0008/0,005
23MnB4	1.5535	0.20/0.25	0.30 max	0.90/1.20	0.025	0.025	0.30 max		0.25	0,0008/0,005
27MnB4	1.5536	0.25/0.30	0.15/0.30	0.90/1.20	0.025	0.025	0.30 max		0.25	0,0008/0,005
30MnB4	1.5526	0.27/0.32	0.30 max	0.80/1.10	0.025	0.025	0.30 max		0.25	0,0008/0,005
36MnB4	1.5537	0.33/0.38	0.30 max	0.80/1.10	0.025	0.025	0.30 max		0.25	0,0008/0,005
37MnB5	1.5538	0.35/0.40	0.30 max	1.15/1.45	0.025	0.025	0.30 max		0.25	0,0008/0,005
30MoB1	1.5408	0.28/0.32	0.30 max	0.80/1.00	0.025	0.025	0.30 max	0.08/0.12	0.25	0,0008/0,005
32CrB4	1.7076	0.30/0.34	0.30 max	0.60/0.90	0.025	0.025	0.90/1.20		0.25	0,0008/0,005
36CrB4	1.7077	0.34/0.38	0.30 max	0.70/1.00	0.025	0.025	0.90/1.20		0.25	0,0008/0,005
31CrMoB2-1	1.7272	0.28/0.33	0.30 max	0.90/1.20	0.025	0.025	0.40/0.55	0.10/0.15	0.25	0,0008/0,005