St3 · 20 · 45 · 40Kh · Ø10–300 · GOST 2590
Hot-rolled round bar
Round bar Ø10–300 mm in St3, 20, 45 and 40Kh to GOST 2590; equivalents Q235B, 20#, 45#, 40Cr
St1kp · St3 · SAE 1008 · Ø5.5–16 · GOST 30136
Steel wire rod
Round product in coils Ø5.5–16 mm in St1kp, St3 and SAE 1008 to GOST 30136; equivalents Q195, Q235
GOST 30136-95GOST 380-2005GB/T 701-2008GB/T 700-2006ASTM A510/A510MSt1kpSt1psSt2kpSt3psSt3spQ195Q235SAE 1006SAE 1008
Parameters
| Parameters | |
|---|---|
| Diameter | 5.5–16 mm; per GOST 30136 — 5.0–9.0 mm, larger — by agreement with the mill |
| Form of supply | coils, coil weight — to specification |
| Steel grade | St1kp, St1ps, St2kp, St3ps, St3sp, SAE 1006, SAE 1008 |
| Cooling | air-cooled; accelerated cooling for drawing — to specification |
| Surface | with mill scale, untreated |
Sizes and weight
| Ø, mm | Weight, kg/m | Metres per tonne |
|---|---|---|
| 5.5 | 0.187 | 5 362 |
| 6 | 0.222 | 4 505 |
| 6.5 | 0.26 | 3 839 |
| 7 | 0.302 | 3 310 |
| 8 | 0.395 | 2 534 |
| 9 | 0.499 | 2 002 |
| 10 | 0.617 | 1 622 |
| 12 | 0.888 | 1 126 |
| 14 | 1.21 | 827.5 |
| 16 | 1.58 | 633.6 |
Theoretical weight at steel density 7.85 g/cm³. Actual batch weight is by scale and mill certificate.
Description
Wire rod is a hot-rolled round product of small diameter, coiled straight off the mill. The technical conditions are set by GOST 30136-95: it covers diameters of 5.0–9.0 mm, wire rod above 9 mm in coils is produced by agreement with the mill, dimensions and tolerances are read from GOST 2590; at mills in China GB/T 701-2008 applies to low-carbon wire rod; grades to GOST 380-2005 are St1kp, St1ps, St2kp, St3ps and St3sp, equivalents Q195 and Q235, for export specifications SAE 1006 and SAE 1008 to ASTM A510/A510M.
The end use determines the grade and the cooling regime. Wire rod for wire drawing is low-carbon St1kp, St2kp, SAE 1006 and SAE 1008: the low carbon content gives ductility in drawing, and by specification the mill rolls it with accelerated cooling so that the scale is removed more easily. Wire rod for tying, mesh, nails and strapping is St3ps and St3sp, Q235. Diameter Ø6.5 goes for drawing, Ø8 and above as stock for construction mesh and small embedded parts.
During inspection at the mill the bureau measures the diameter with a micrometer in two perpendicular directions on several turns of the coil and compares the ovality with the tolerance, checks the surface — free of laps, cracks and signs of overheating, the condition of the scale, and the coil weight on the mill scales. The heat number on the coil tag is checked against the mill test certificate (MTC), the carbon and manganese content against the specification. Strapping of coils and legibility of tags are recorded in the inspection report with photographs before shipment.
Applications
- wire drawing at hardware and fastener plants
- tying wire and bundle strapping
- welded masonry and road mesh
- nails, staples and fasteners
- small embedded parts and lifting loops in precast concrete
Packing and shipment
Coils strapped with wire rod or band at several points, mill tag on every coil with grade, heat, diameter and weight.
Grade equivalents
| GOST | GB (China) | ASTM | EN | Note |
|---|---|---|---|---|
| St3sp | Q235B | A36 | S235JR | Nearest equivalents: carbon, manganese and impact toughness limits differ between the standards. The specification fixes the GOST grade and the control values. |
| Steel 20 | 20# | 1020 | C22E | Quality carbon steel; the equivalents match in carbon content, impurity limits are checked against the certificate. |
| Steel 45 | 45# | 1045 | C45E | Steel for heat treatment; hardness and delivery condition are checked — hot-rolled, normalised or annealed. |
| 40Kh | 40Cr | 5140 | 41Cr4 | Chromium alloy steel; the equivalents are close in composition, chromium content is confirmed by the heat certificate. |
| 09G2S | Q355B | A572 Gr. 50 | S355JR | Nearest equivalents by strength; 09G2S specifies impact toughness at minus 40 °C, the equivalents use other test temperatures. |
| St1kp | Q195 | 1008 | — | Wire rod for drawing and tying wire; the nearest equivalent by carbon content, there is no single EN grade for this class. |
| 08Kh18N10 | 06Cr19Ni10 | 304 | 1.4301 | Austenitic chromium-nickel steel; nearest equivalents: chromium and nickel ranges differ between the standards, composition is confirmed by the heat certificate. |
| 12Kh18N10T | 06Cr18Ni11Ti | 321 | 1.4541 | Titanium-stabilised; nearest equivalents: the upper carbon limit is 0.12 % for 12Kh18N10T and 0.08 % for 321 and 1.4541; titanium content is checked against the certificate. |
| 03Kh17N14M3 | 022Cr17Ni12Mo2 | 316L | 1.4404 | Molybdenum-bearing, low-carbon; nearest equivalents: the lower nickel limit of 03Kh17N14M3 is higher than that of 316L, composition is confirmed by the heat certificate. |
Equivalents are the closest match, not identical: chemistry and tolerances differ between standards. The exact grade and standard are written into the contract.
Related items
St3 · 09G2S · 20×4–200×40 · GOST 103
Hot-rolled flat bar
Flat bar of rectangular cross-section 20×4–200×40 mm in St3 and 09G2S to GOST 103; equivalents Q235B and Q355B
Buyer questions
How to read a mill test certificate (MTC) for long products
In the certificate the mill states the heat number, grade and standard, the chemical composition of the heat, the mechanical properties from test results, the size and weight of the batch. The heat number must match the tag on the bundle or coil — this is the first thing the bureau's inspector checks. If the mill rolled to GB, the bureau attaches to the certificate a table of GOST-to-GB grade correspondence and the control values from the specification.
How St3 differs from steels 20, 45 and 40Kh
St3 is an ordinary-quality steel to GOST 535: strength is specified, impurities are allowed within wider limits; it goes into structures and non-critical parts. Steels 20 and 45 are quality carbon steels to GOST 1050: impurities are limited more tightly, properties are set by carbon content, steel 45 is used for hardening and quench-and-temper treatment. 40Kh is a chromium alloy steel to GOST 4543 for shafts, axles and gears after heat treatment. The grade is chosen from the part drawing, not from what is in stock.
How the tonnage of long products is calculated
The theoretical weight per metre is calculated from the cross-sectional area and the steel density of 7.85 g/cm³: round bar 0.006165·d², square bar 0.00785·a², flat bar 0.00785·b·t in kilograms per metre with dimensions in millimetres. The specification and the contract with the mill are drawn up on theoretical weight. Shipment and acceptance at the warehouse go by actual weight from weighing; the difference from theory lies within the dimensional tolerances of the standard.
What the bureau checks when inspecting a batch at the mill
Cross-section — with a micrometer and a calliper in two perpendicular directions on bars from different bundles, checked against the GOST tolerances for the rolling accuracy class. Documents — the heat number on the tag against the certificate, the chemical composition against the specification, for stainless grades a rapid composition check with a portable spectrometer. Appearance — surface free of cracks, laps and scabs, straightness, twist of square and hexagonal bar. Packing — strapping of bundles, a legible tag, grade marking on the bar ends. Everything is recorded in an inspection report with photographs.
How a batch is sized and what to send for a quotation
The batch is sized to your volume — send your specification: steel grade to GOST, product type and cross-section size, rolling accuracy class, bar length or coil weight, volume in tonnes for each size, certificate and packing requirements. On the specification the bureau selects a mill, agrees terms with it and returns to you a draft contract describing inspection and acceptance.
Price request
Send your specification and we will quote your batch
Steel pricing depends on grade, size, tonnage and delivery terms on the day of contract. A number on the page would be wrong by the time you read it.
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