Comparison of Hot Rolled Steel Grades

In metalworking, rolling is a metal forming process in which metal stock is passed through one or more pairs of rolls to reduce the thickness and to make the thickness uniform. The concept is similar to the rolling of dough. Rolling is classified according to the temperature of the metal rolled. If the temperature of the metal is above its recrystallization temperature, then the process is known as hot rolling.
Typical uses for cold-rolled steel include metal furniture, desks, filing cabinets, tables, chairs, motorcycle exhaust pipes, computer cabinets and hardware, home appliances and components, shelving, lighting fixtures, hinges, tubing, steel drums, lawn mowers, electronic cabinetry, water heaters, metal containers, and a variety of construction-related products.

There are three different grades for cold rolled steel in China:Q195,Q215, Q235.and SPHC.

Hot Rolled Steel Designations & Grades with Comparisons:

Quality	STANDARD	STEEL GRADE
General structural steel (including chequered steel)	GB/T 700-2006 EN 10025-2004 JIS G3101-2004 ASTM A36-05 ASTM A573-05	Q235 (A/B/C/D); Q275 (A/B/C/D) S235JR (ST37-2), S235JO (ST37-3), S275JR (ST44-2) SS400; SS490 A36 Grade 65; Grade 70
Cold forming steel	GB/T 700-2006 EN 10111-2008 JIS G3131-2005	Q195; Q215 (A/B) DD11 (StW22); DD12 (StW23); DD13 (StW24) SPHC; SPHD; SPHE
High strength low alloy structural steel	GB/T 1591-2008 EN 10028-3-2003 EN 10025-2004 ASTM A572-07 ASTM A588-05	Q345 (A/B/C/D/E); Q390; Q420 P355N S420N Grade 50; Grade 60 Grade A; Grade B
Steel for boiler and other pressure vessels	GB 713-2008 ASTM A537-08 JIS G3115	Q245R (20g/20R); Q345R (16Mng/16MnR) Class 1/2/3 SPV235; SPV315; SPV355
Machine structural steel	GB/T 699-1999 EN 10083-1 JIS G4051-2005 ASTM A29-05 SAE J403-95	20#; 35#; 45# C20E; C35E; C45E S20C; S35C; S45C 1020; 1035; 1045 SAE1020; SAE1035; SAE1045
Steel for ship building	LR; ABS, BV, GL, DNV, CCS	A/B/D

For Chemical Composition & Mechanical Properties of Hot Rolled China Steel refer to the table:

	Chemical Composition %					Mechanical Properties
Steel Brand	C	SiS	Mn	P	S	Elongation %	Yield Strength Mpa	Tensile Strength Mpa
Q195	0.06-0.12	<=0.30	0.25-0.50	<=0.045	<=0.050	>=33	>=195	315-430
Q215	0.09-0.15	<=0.30	0.25-0.55	<=0.045	<=0.050	>=31	>=215	335-450
Q235	0.14-0.22	<=0.30	0.30-0.65	<=0.045	<=0.050	>=26	>=235	375-500
SPHC	0.01-0.06	<=0.05	0.19-0.50	<=0.03	0.001-0.007	>=46	>=305	>=370