Y12Pb U72121 - GB /T 8731-2025

Grade	Y12Pb
China ISC	U72121
Corresponding Standard	GB /T 8731-2025 Free-Cutting Structural Steels
Classification	Carbon Steel

Y12Pb Chemical Element Composition Content (%)

Component	C	Si	Mn	P	S	Pb
Minimum Value	-	-	0.85	0.04	0.26	0.15
Maximum Value	0.15	0.15	1.15	0.09	0.35	0.35

Y12Pb Mechanical Properties

diameter d mm	Heat Treatment or Condition	Tensile Strength σ_b Mpa	Elongation or Extension Rate δ %	Hardness HBW
d≤20 (Sample Diameter)	Hot Rolled (forged）	360~570		≤169
8＜d≤20 (nominal size)	Cold Drawn	480~810	≥7	140~217
20＜d≤30 (nominal size)	Cold Drawn	460~710	≥7	140~217
d > 30 (nominal size)	Cold Drawn	360~710	≥7	140~217

1 Approximate Comparison Table Free-Cutting Structural Steel

China		United States	International Organization for Standardization	Germany		France
GB	ISC	ASTM/AISI	ISO	DIN EN/DIN	W-Nr.	NF EN/NF
Y12Pb	U72122	11L08	11SMnPb28	10SPb20	1.0722	10PbF2

2 Approximate Comparison Table Free-Cutting Structural Steel

China	Japan	United States	International Organization for Standardization
GB	JIS	ASTM/AISI	ISO
Y12Pb GB/T 8731-2025	SUM24L JIS G4804-2019	12L14 ASTM A29/A29M-16	11SMnPb30 ISO 683-4-2016

Y12Pb Corresponding Standards(Same grade name, different standards)

Note: The data is for reference only! If you have any questions, please fill out "I want to correct it"!