Description

EN8 Steel Round Bar (corresponding to British Standard BS 970:080M40) is a medium-carbon non-alloy structural steel characterized by high strength, good machinability, and heat treatability, but poor weldability. We can supply steel round bars of various specifications and grades, such as: Cr12 Too Steel Bar, AISI 4140 Steel Bar, 42CrMo Steel Round Bar, X45NiCrM04 (1.2767) Steel Round Bar, etc. Please feel free to inquire.

Characteristics of EN8 Steel Round Bar:

1. Chemical Composition: Carbon (C) 0.36%–0.44%, Manganese (Mn) 0.60%–1.00%, Silicon (Si) 0.17%–0.37%, Phosphorus (P) ≤0.05%, Sulfur (S) ≤0.05%, trace amounts of chromium/nickel/molybdenum.

2. Mechanical Properties (Delivery Condition, Untreated): EN8 Steel Round Bar tensile strength ≥570 MPa, yield strength ≥335 MPa, elongation ≥19%, hardness ≤217 HBS; after quenching and tempering, strength and hardness are significantly improved (e.g., tensile strength can reach 700–900 MPa, hardness HB 200–300).

3. Machining Performance: EN8 Steel Round Bar has good machinability and is suitable for conventional machining operations such as turning, milling, and drilling. It has moderate cold and hot forming capabilities, but poor weldability, requiring preheating (≥150℃) and slow cooling after welding to prevent cracking.

4. Heat Treatment Characteristics: EN8 Steel Round Bar can have its strength and wear resistance improved by normalizing (860℃) or quenching and tempering (quenching at 840℃, tempering at 500–600℃). Hardenability is low, and the core hardness is insufficient in large sections. It is prone to cracking during water quenching and is best treated with oil quenching.

5. Corresponding Grades: According to standard BS 970-1-1983, similar grades of EN8 Steel Round Bar in other national/regional standards include: China GB 40, Japan JIS S40C, USA ASTM 1040, International Organization for Standardization ISO C40E4, Germany DIN EN C40E, France NF EN XC42, and the UK BS EN 080M40, etc.

Applications of EN8 Steel Round Bars:

EN8 Steel Round Bars are primarily used in the manufacture of mechanical parts requiring high strength, wear resistance, and machinability. They are commonly found in the automotive, construction machinery, and general machinery industries.

1. Transmission and Shaft Components: EN8 Steel Round Bars are used for components such as drive shafts, spindles, crankshafts, piston rods, pins, and couplings.

2. Gears and Sprockets: Small and medium-sized gears, sprockets, and cams (often used after normalizing or tempering).

3. Bearing Housings and Fasteners: EN8 Steel Round Bars are used for non-precision bearing housings, high-strength bolts, and nuts (requiring heat treatment to improve performance).

4. Hydraulic and Pneumatic Components: Pistons, valve cores, and piston rings (surface hardening improves wear resistance).

5. General Mechanical Structural Components: Forgings or machined parts subjected to medium to high stress, such as connecting rods, rocker arms, and levers.

Specifications of the Steel Round Bar:

Brand	Carbon Steel, mm
Q195、Q215A、Q215B、Q235A、	1.5～ 25.4 ×780～2100× 2000 ～12000
Q235B、Q235C、Q235D	1.5～ 25.4 ×780～2100× 2000 ～12000
SS330、SS400	1.5～25.4 ×780～2100× 2000 ～ 12000
S235JR+AR、S235J0+AR、S275JR+AR、S275J0+AR	1.5～25.4 ×780～2100× 2000 ～ 12000
SPHC、SPHD	1.5～14.0×780～2100× 2000 ～ 12000
SPHE	1.5 ～ 6.0 ×780 ～2100× 2000 ～ 12000
DD11、DD12、DD13	1.5 ～ 8.0 ×780 ～2100× 2000 ～ 12000
HCP

Brand	Appropriate standard
Q195、Q215A ～ Q235D	GB/T 709
SS330、SS400	JIS G 3193
S235JR+AR、S235J0+AR	EN 10029
S275JR+AR、S275J0+AR	EN 10029
SPHC、SPHD、SPHE	JIS G3193
DD11、DD12、DD13	EN 10051
HCP	WJX(RZ)571

S45C	0.42~0.48	0.60~0.90	0.15~0.35	≤0.03	≤0.03	≤0.20	≤0.20	≤0.30	_	_	JIS G4051-2005
S20C	0.18~0.23	0.30~0.60	0.15~0.35	≤0.03	≤0.035	≤0.20	≤0.20	≤0.30	_	_	JIS G4051-2005
ASTM A36	≤0.22	0.50~0.90	≤0.40	≤0.040	≤0.050	≤0.20	≤0.20	≤0.30	≥250	400~500	ASTM A36/A36M-03a
ASTM A105	≤0.35	0.6-1.05	≤0.35	≤0.050	≤0.040	≤0.20	≤0.20	≤0.30	≥310	485~620	ASTM A105/A105M
SAE1013	0.11~0.16	0.50~0.80	_	≤0.040	≤0.050	≤0.20	≤0.20	≤0.30	_	_	ASTM A568/A568M-91a
SAE1015	0.13~0.18	0.30~0.60	_	≤0.040	≤0.050	≤0.20	≤0.20	≤0.30	_	_
SAE1017	0.15~0.20	0.30~0.60	_	≤0.040	≤0.050	≤0.20	≤0.20	≤0.30	_	_
SAE1018	0.15~0.20	0.60~0.90	_	≤0.040	≤0.050	≤0.20	≤0.20	≤0.30	_	_
SAE1020	0.18~0.23	0.30~0.60	_	≤0.040	≤0.050	≤0.20	≤0.20	≤0.30	_	_
S235JR	0.15~0.20	≤1.4	_	≤0.035	≤0.035	≤0.20	_	_	≥235	400~510	EN10025
S275JR	≤0.22	≤1.4	_	≤0.035	≤0.035	≤0.20	_	_	≥275	490~610	EN10025
ST37-2	0.17~0.20	≤1.4	_	≤0.045	≤0.045	≤0.20	_	_	≥235

Diameter (mm)	Theoretical Weight (kg/m)	Diameter (mm)	Theoretical Weight (kg/m)
5.5	0.186	13	1.04
6	0.222	14	1.21
6.5	0.26	15	1.39
7	0.302	16	1.58
8	0.395	17	1.78
9	0.499	18	2
10	0.617	19	2.23
* 11	0.746	20	2.47
12	0.888	21	2.72
22	2.98	63	24.5
* 23	3.26	* 65	26
24	3.55	* 68	28.5
25	3.85	70	30.2
26	4.17	75	34.7
* 27	4.49	80	39.5
28	4.83	85	44.5
* 29	5.18	90	49.9
30	5.55	95	55.6
* 31	5.92	100	61.7
32	6.31	105	68
* 33	6.71	110	74.6
34	7.13	115	81.5
* 35	7.55	120	88.8
36	7.99	125	96.3
38	8.9	130	104
40	9.86	140	121
42	10.9	150	139
45	12.5	160	158
48	14.2	170	178
50	15.4	180	200
53	17.3	190	223
* 55	18.6	200	247
56	19.3	220	298
* 58	20.7	250	385
60	22.2

Standards and Classifications

Products	Round Steel bar
Dia	5.5mm~650mm
Length	3m,6m,9m,12m
Standard	ASTM A 615 Gr 40/60,BSS4449 Gr460B,500B etc
Material	3Cr2Mo/1.2311/1.2312/P20/1.2738/718H/P20+Ni/1.2316/1.2083/4Cr13 /sus420j2/420/S136/NAK80H13/1.2344/SKD61/5CrNiMo/SKT4/1.2714 Cr12/D3/1.2080/Cr12MoV/D2/1.2379/SKD11/9CrWMn/O1/1.2510/SKS3 /DC53 40Cr/5140/35CrMo/42CrMo/4140/1.7225 C45/C50/1045/1050/S50C/S45C/T10/T8 M2/1.338/SKH51
Surface	ASTM，AISI，JIS，GB， DIN，EN
Technique	Hot rolled / cold rolled
Surface	Black Finish ,Oiled,Shot Blasted,Spray Paint,Coated,Galvanized,
Surface	Or as Your Request
Package	In bundle, no other package or wrapped with waterproof, or as customers’ requirement
Payment Term	T/T, L/C at sight,West Union,Paypal
Price Term	FOB,CRF,CIF,EXW all acceptable