Description

Hot rolled steel round bars are solid, long steel bars with a circular cross-section, formed by high-temperature rolling of steel billets. They are characterized by good hardenability, high hardness, and excellent wear resistance, but their dimensional accuracy and surface finish are lower than those of cold-drawn round bars.

Characteristics of Hot Rolled Steel Round Bars:

1. Surface Characteristics: Hot rolled steel round bars have a layer of iron oxide scale on their surface, appearing grayish-black and relatively rough, without textured ribs, resulting in weaker adhesion to concrete.

2. Mechanical Properties: High-temperature rolling refines the grain size and welds internal bubbles, resulting in a denser microstructure; it possesses good plasticity and toughness, but its dimensional accuracy and surface finish are lower than those of cold-drawn round bars.

3. Process Advantages: High production efficiency, low energy consumption, low cost; can produce large-sized products (up to 380 mm in diameter), and the delivered condition is equivalent to normalizing treatment, with good hardenability.

4. Size Range: Standard sizes for Hot Rolled Steel Round Bars range from 5.5-250 mm. Smaller sizes (5.5-25 mm) are typically supplied in coils or straight bars, while larger sizes are often used for mechanical parts or seamless steel pipe blanks.

5. Main Disadvantages: Uneven cooling can lead to residual stress, potentially affecting fatigue resistance and stability; larger dimensional tolerances (e.g., ±0.8 mm for diameters > 50 mm) make it unsuitable for direct use in high-precision parts, requiring further processing.

For parts requiring high precision and high surface quality, cold-drawn or forged round bars are recommended as alternatives.

Applications of Hot Rolled Steel Round Bars:

1. Construction Engineering: Hot Rolled Steel Round Bars are used for auxiliary reinforcement, embedded parts, and steel structure connectors in reinforced concrete structures; due to their smooth surface, their bond strength with concrete is weaker than that of ribbed steel bars, and they are mostly used in non-critical load-bearing areas.

2. Machinery Manufacturing: Hot Rolled Steel Round Bars are a core raw material for manufacturing shafts (such as drive shafts and crankshafts), gears, connecting rods, and bearing rings. Medium carbon steel (such as 45) is used in important load-bearing components after quenching and tempering, while alloy steel (such as 40Cr and 20CrMnTi) is used for high-load gears and key components.

3. Energy and Heavy Industry: Hot Rolled Steel Round Bars are used in the petroleum industry to manufacture sucker rods, drill bits, and oil well equipment parts; in the wind power sector, they are used for wear-resistant gearbox components; some special materials (such as non-magnetic steel) are used for demagnetizing load-bearing components in motors.

4. Transportation: Hot Rolled Steel Round Bars are widely used in automobile chassis, axles, suspension system components, as well as structural components and anchor chains in shipbuilding.

5. Hot Rolled Steel Round Bars with different chemical compositions are suitable for different working conditions: Carbon structural steel (Q235, etc.) is mainly used for building and general connecting parts; high-quality carbon steel (10-45) is mainly used for general mechanical parts; alloy structural steel (35CrMo, 42CrMo, etc.) is used for extreme environment components with stringent requirements for strength, toughness and fatigue resistance, such as engine connecting rod bolts and heavy-duty tire bolts.

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