Description

Cold drawn steel round bars (also known as cold-drawn bright round bars) are circular cross-section steel round bars made by forcefully drawing hot rolled steel round bars through a die at room temperature, causing plastic deformation. The diameter is typically between Ф3mm and Ф100mm. Compared to hot-rolled round steel, their tensile strength and yield strength are significantly improved, with a high surface finish and no oxide scale, making them suitable for direct use in precision assembly.

Characteristics of Cold Drawn Steel Round Bars:

1. Improved Mechanical Properties: Cold working strengthens the steel, refines the grain size, and increases dislocation density, resulting in a 30%-90% increase in tensile strength, a 20%-30% increase in yield strength, and a significant increase in hardness.

2. Extremely High Dimensional Accuracy: Under die constraints, the diameter tolerance of Cold Drawn Steel Round Bars can be controlled within ±0.05mm, with a straightness deviation ≤0.5mm/m. Accuracy grades can reach h8-h10, allowing for direct use in some precision applications without secondary processing.

3. High surface finish: Cold Drawn Steel Round Bar has a low surface roughness (Ra≤0.8μm, high-quality products can reach Ra0.4μm), no oxide scale, and a smooth and clean appearance, which helps reduce friction and subsequent polishing.

4. Decreased plasticity and toughness: As strength increases, the elongation (plasticity) of Cold Drawn Steel Round Bar decreases, its cold bending performance deteriorates, and it is more sensitive to stress concentration. Its weldability is also inferior to hot-rolled round bar.

5. Diverse materials: Cold Drawn Steel Round Bar is available in carbon steel bar (such as Q235, 45), mild steel round bar, alloy steel round bar (such as 40Cr, 20CrMo), and stainless steel bar, with specifications typically ranging from Φ3mm to Φ100mm.

6. Economic advantages: High material utilization rate; small machining allowance saves on subsequent cutting costs. However, the complex production process results in a higher unit price than ordinary hot-rolled round bar.

Applications of Cold Drawn Steel Round Bars:

Cold Drawn Steel Round Bars, characterized by high dimensional accuracy (tolerance within ±0.05mm), smooth surface, and strong mechanical properties, are primarily used in the machinery manufacturing and precision parts industries where strict precision and strength requirements are placed. They can often be used directly without extensive machining.

1. Machinery Manufacturing: Cold Drawn Steel Round Bars are widely used in the manufacture of various shafts (such as motor shafts and drive shafts), pins, gears, guide rails, and precision connecting rods, meeting the demands for high stability and wear resistance.

2. Automotive and Motorcycle Parts: Cold Drawn Steel Round Bars are used in the production of steering system components, suspension arms, half shafts, chains, and brake lines, requiring high fatigue strength and dimensional consistency.

3. Standard Parts and Fasteners: Serving as high-quality blanks for bolts, screws, nuts, studs, and pipe fittings, their strength is enhanced by cold work hardening.

4. Electronics and Instrumentation: Cold Drawn Steel Round Bars are used in miniature precision parts such as electronic terminal pins, CD/DVD drive components, scanner assemblies, watch components, eyeglass frames, and medical devices.

5. Light Industry and Hardware: Covering internal structural components for household appliances, parts for office equipment (printers, fax machines), metal fittings for furniture, fishing gear, and structural components for pens and toys.

Specifications of the Steel Round Bar:

Carbon Structural Steel Bright Round Bar	C10 C20 C35 C45 c55 St37-2 St37-3 St44-2 St44-3 St52-3	S10C S20C S25C S35C S45C S48C S50C S55C	1010 1020 1035 1045 1055	10# 20# 25# 35# 45# 20Mn 45Mn
Low – Alloy High – Strength Structural Steel Bright Round Bar	S235JR S235J0 S235J2 S275JR S275J0 S275J2 S355JR S355J0	S355J2 S275J0G3 S275J2G4 S355J2G3 S355J2G4 S355k2G3 S355K2G4 S355K2 S355J2G4	S275N S355N S355NL S420N S420NL S460N S460NL	Q355B Q355D Q390B Q390D
Alloy Structural Steel Bright Round Bar	20Mn2 30Mn2 40Mn2 20Cr 40Cr 15CrMo 20CrMo 30CrMo 42CrMo 41Cr4 16MnCr5 42CrMoS4	12Cr1MoV 20CrMnTi 20CrNiMo 40CrNiMo SAE1541 4120 4135 4140 4320 4340 8620H SCM415 SCM420	SCM430 SCM435 SCM440 SCr420 SCr420H SCr435 SCr440 34CrMo4 SNCM439 34Cr4	42CrMo4 39NiCrMo3 34CrNiMo6 18CrMo4 20NiCrMo2-2
Inconel Alloy Superalloys	Inconel601 InconeX750 Inconel600 Incoloy825 Inconel718	Incoloy800H Incoloy 800H Incoloy800 Inconel625 Inconel625 Inconel690	GH4099 GH128 GH145 GH169 GH605 GH3536 GH4033 GH99 GH625 GH4080AGH2132	GH132 GH500 GH600 GH536 GH4141 GH141 GH3625 GH2747 GH188 GH2696 GH747 GH3030

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

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

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