ML28B A70284 - GB T 6478-2001

Grade	ML28B
China ISC	A70284
Corresponding Standard	GB T 6478-2001 Steels for cold heading and cold extruding
Classification	Alloy Steel

ML28B Chemical Element Composition Content (%)

Component	C	Si	Mn	P	S	Cr ^*	Ni ^*	Cu ^*	B	Al ^ⓐ
Minimum Value	0.25	-	0.6	-	-	-	-	-	0.0005	0.02
Maximum Value	0.32	0.4	0.9	0.035	0.035	0.2	0.2	0.2	0.0035	-

①By agreement between the supplier and the purchaser, other grades of cold heading and cold extrusion steel may be supplied.
②Permissible deviations in the chemical composition of the steel shall comply with the relevant provisions of GB/T 222-1984.

ML28B Mechanical Properties

condition	Heat Treatment or Condition	Tensile Strength σ_b Mpa	Yield Point σ_s Mpa	Elongation or Extension Rate δ %
Steel	Annealing	≤530		≥62
Sample diameter d=25	Normalizing temperature 870~900°C, Quenching temperature 850~890°C water or oil cooling, Tempering temperature 550~660°C	≥630	≥480	≥14

New and Old Grade Replacement List

Corresponding Standard	Grade
GB T 6478-2001	Grade China ISC
GB /T 6478-2015	Grade China ISC Old Grade

Approximate Comparison Table Steel for Cold Heading and Cold Extrusion

China		Japan	United States	International Organization for Standardization	European Standard
GB	ISC	JIS	ASTM/AISI	ISO	EN
ML30B GB/T 6478-2015 ML28B GB/T 6478-2001	A70304	SWRCHB 331 JIS G3508-1	10B30 ASTM A29/A29M-12 ASTM A510/A510-13	CE28B ISO 4954-1993	28B2 EN 10263-4-2001

ML28B Corresponding Standards(Same grade name, different standards)

1	GB T 6478-2001
	ML28B A70284
2	GB /T 6478-2015
	(ML28B) ML30B A70304
3	GB /T 5953.1-2009
	ML28B
4	GB /T 28906-2025
	ML28B

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