Description

Steel round bars are solid, long steel bars with a circular cross-section, smooth surface, and no ribs. Their specifications are expressed in diameter (mm). They are mainly classified by manufacturing process and material. They are characterized by good machinability and high plasticity, but weak adhesion to concrete.

Characteristics and Classification of Steel Round Bars:

Circular cross-section, smooth surface, no texture or ribs; good plasticity, easy to process (turning, milling, welding, forging), but relatively low strength and weak adhesion to concrete; materials include low-carbon steel (e.g., Q235, 10), medium-high carbon steel (e.g., 45), alloy steel (e.g., 40Cr, 20CrMnTi), and stainless steel (e.g., 304, 316); theoretical weight formula: Φ² × 0.00617 kg/m.

1. Classification by manufacturing process: Hot-rolled Steel Round Bar (5.5–250 mm, low cost, oxide scale surface), Forged Steel Round Bar (dense structure, used for critical component blanks, such as EN8 Steel Round Bar), Cold-drawn Steel Round Bar (precise dimensions, bright surface, high strength, used for precision shafts).

2. Classification by Material: Carbon structural steel (e.g., Q235, 20, for construction/general parts), high-quality carbon steel (e.g., 45, 65Mn, for machine parts), alloy steel (e.g., 40Cr, GCr15, X45NiCrM04 (1.2767) Steel Round Bar, for high-strength wear-resistant parts), stainless steel (e.g., 304/316, for corrosion-resistant applications), tool steel (e.g., T8/T10, for cutting tools and dies).

3. Classification by Common Size: Small Steel Round Bar (≤25 mm, mostly bundled for bolts/reinforcing bars), large round steel (>25 mm, used for shafts/tube blanks/machining); hot-rolled specifications are mainly 5.5–250 mm, cold-drawn/forged steel can achieve larger or higher precision.

Steel Round Bar differs from threaded steel rebar (ribbed, high-strength, used as main reinforcement in concrete). It is mostly used for machine parts, shafts, bolts, dies, and structural components, and rarely as concrete reinforcing bars (only used as stirrups and other structural reinforcement).

Applications of Steel Round Bars:

Steel round bars have a wide range of applications, mainly categorized into five major areas based on material, specifications, and processing methods: construction, machinery manufacturing, mold tools, hardware structures, and special industry applications.

1. Construction Engineering: Small-diameter (5.5–25 mm) low-carbon steel round bars (such as Q235, HPB300) are used as non-prestressed reinforcing bars, anchor bolts, tie rods, embedded parts, and scaffolding accessories; however, due to their smooth round surface and weak adhesion to concrete, they are not used as main load-bearing reinforcement (main reinforcement is mostly made of ribbed threaded steel).

2. Machinery Manufacturing: Medium and large-diameter (>25 mm) carbon structural steel (such as 20, 45) and alloy steel (such as 40Cr, 42CrMo steel round bar) steel round bars are used to process key mechanical parts such as shafts, gears, connecting rods, pins, bolts, and flanges, often requiring tempering or normalizing treatment; cold-drawn/forged round bars are more suitable for high-precision shafts.

3. Molds and Tools: High-carbon or alloy tool round bars (such as Cr12 Too steel bar, T8–T12, Cr12MoV, GCr15) are heat-treated to manufacture stamping dies, deep drawing dies, thread rolling dies, measuring tools, bearing rings, drill bit blanks, etc., requiring high hardness, wear resistance, or impact resistance.

4. Hardware and General Parts: Small round bars (≤25 mm) are directly used to produce everyday hardware or simple structural parts such as nails, hooks, U-bolts, wrenches, railings, and decorative parts; they can also be used as raw materials for steel wire and cable.

5. Special Industries: Stainless steel round bars (such as 304, 316) are used in chemical pipelines and food processing equipment; heat-resistant/alloy round bars (such as 40CrMo, 25Cr2MoVA) are used in wind turbine main shafts, oil drill pipes, and fasteners; high-temperature alloy or titanium alloy round bars are used in aerospace components.

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