If you want to know more information, like quotation, products, solutions, etc., please contact us online.
Tianjin Sanon Steel Pipe Co., Ltd. is a stockist. Our stock factory is in Cangzhou City, Hebei Province. Our main sources of goods are boiler pipes, and the representative materials are ASTM A335 P5/P11/P91/P92, ASME SA-106/SA-106M GR.B, GB/T 3087-2008 10#/20#. The representative materials of pipeline pipes are API 5L, API 5CT, the representative materials of petroleum cracking pipes GB/T 9948 are 15MoG/12CrMoVG. GB/T 6479-2013 represents the material 10#/20#, heat exchanger tubes SA179/SA210/SA192, etc., mechanical tubes GB/T 8162 represent the material 10#/20#/Q345/42CrMo, EN10210 represents the material S355JOH/S355J2H, gas cylinder tubes GB1 8248, represent the material 34CrMo4/30CrMo.
— A Comprehensive Guide to the Russian Cold-Formed Seamless Pipe Standard and Material
Sanon Pipe – Your Trusted Supplier of GOST-Compliant Precision Steel Tubes
1. Standard System Overview: The Complementary Relationship Between GOST 8734 and GOST 8733
GOST 8734-75 is the dimensional / assortment standard for cold-formed (cold-drawn / cold-rolled) seamless steel pipes in Russia (formerly USSR). It specifies the outer diameter range, wall thickness series, dimensional tolerances, length types and allowable deviations, and theoretical weight of the pipes. The cold-drawing process achieves far higher dimensional accuracy than hot-rolled pipes, making it an ideal choice for precision instruments, hydraulic systems, high-accuracy mechanical structures, and similar applications.
In the Russian standards system, GOST 8734-75 must be used together with its companion technical conditions standard GOST 8733-87. In essence, GOST 8734-75 defines “what the pipe looks like” (dimensions and tolerances), while GOST 8733-87 defines “what material it is and how strong it is” (composition and performance).
| Standard | Chinese Title | Scope |
|---|---|---|
| GOST 8733-87 | Cold-formed seamless steel pipes – Technical conditions | Steel grades, chemical composition, mechanical properties, process tests, hydrostatic tests, inspection rules, marking, packaging |
| GOST 8734-75 | Cold-formed seamless steel pipes – Dimensional assortment | Outside diameter range, wall thickness series, dimensional tolerances, length types and allowable deviations, theoretical weight |
Procurement Tip: In engineering documents or purchase orders, GOST 8733 and GOST 8734 are almost always referenced together; they form a complete product standard for the pipe.
2. Detailed Material Description: Steel 20 (Grade 20)
Steel 20 (Russian designation Ст20) is the most commonly used high-quality carbon structural steel under the GOST 8734 standard, offering a well-balanced combination of properties. Unlike the hot‑rolled 20 steel in GOST 8731, the cold‑drawn Steel 20 provides superior dimensional accuracy and surface quality.
Chemical Composition (%)
| Element | Content Range | Role / Effect |
|---|---|---|
| C (Carbon) | 0.17 – 0.24 | Ensures balance between strength and toughness |
| Mn (Manganese) | 0.35 – 0.65 | Increases strength and hardenability |
| Si (Silicon) | 0.17 – 0.37 | Enhances oxidation resistance |
| P (Phosphorus) | ≤ 0.030 | Controls cold brittleness tendency |
| S (Sulphur) | ≤ 0.035 | Reduces hot shortness risk |
| Cr (Chromium) | ≤ 0.25 | Improves corrosion resistance |
| Ni (Nickel) | ≤ 0.30 | Enhances toughness |
| Cu (Copper) | ≤ 0.30 | Improves weather resistance |
Mechanical Properties
| Property | Value | Test Standard |
|---|---|---|
| Tensile strength (σb) | ≥ 412 MPa | GOST 1497 |
| Yield strength (σs) | ≥ 245 MPa | GOST 1497 |
| Elongation after fracture (δ5) | ≥ 21% | GOST 1497 |
| Hardness (HB) | ≤ 156 HB | GOST 9012 |
3. Dimensional Range and Tolerances (Core of GOST 8734-75)
Dimensional Range
The cold‑drawing process endows the pipe with extremely high dimensional accuracy. Outside diameter tolerances can reach as tight as ±0.15 mm or ±0.8%, meeting stringent requirements of precision machinery and hydraulic systems:
| Parameter | Range |
|---|---|
| Outside diameter (OD) | 1 – 200 mm |
| Wall thickness (WT) | 0.2 – 22 mm |
| Length | Random length 1.5 – 11.5 m; fixed length 4 – 9 m |
Outside Diameter Tolerances
| OD Range (mm) | Allowable Deviation (mm) |
|---|---|
| 5 ≤ OD ≤ 10 | ±0.15 |
| 10 < OD ≤ 30 | ±0.30 |
| 30 < OD ≤ 50 | ±0.40 |
| OD > 50 | ±0.8% |
Wall Thickness Tolerances
| WT Range (mm) | Allowable Deviation |
|---|---|
| WT ≤ 1 | ±0.12 mm |
| 1 < WT ≤ 5 | ±10% |
| WT > 5 | ±8% |
Straightness Requirements (per metre length)
| OD Range (mm) | Maximum Curvature |
|---|---|
| 5 – 8 | ≤ 3 mm |
| 8 – 10 | ≤ 2 mm |
| > 10 | ≤ 1.5 mm |
Note: For pipes 20–90 mm in diameter, tighter straightness limits can be offered upon special request.
4. International Grade Equivalents
Steel 20 corresponds closely to grades in other international standards, facilitating global selection and substitution:
| Standard System | Equivalent Grade |
|---|---|
| China (GB) | 20# (GB/T 699 high-quality carbon structural steel) / 20G (for high-pressure boilers) |
| USA (ASTM) | A106 Gr.B |
| Japan (JIS) | S20C |
5. Key Advantages of the Cold‑Drawing Process
Compared with hot‑rolled pipes, GOST 8734‑75 cold‑drawn seamless pipes offer the following distinct benefits:
| Advantage | Technical Explanation | Customer Value |
|---|---|---|
| High dimensional accuracy | Tight tolerances achieved by cold drawing | Perfect fit for high‑precision machinery and hydraulic systems |
| Smooth internal surface | Reduced internal roughness lowers fluid resistance | Enhances efficiency in hydraulic and pneumatic systems |
| Good mechanical strength | Adequate tensile and yield strength | Suitable for pressure‑bearing and structural uses |
| Wide size range | OD 1–200 mm, WT 0.2–22 mm | Meets diverse engineering and design needs |
6. Typical Application Fields
GOST 8734‑75 / Steel 20 cold‑drawn seamless pipes are widely used in the following scenarios:
| Application Area | Specific Use | Rationale for Selection |
|---|---|---|
| Oil & gas transport | Low‑pressure pipelines | Good weldability, moderate strength |
| Heat exchange equipment | Heat exchanger / condenser tube bundles | High dimensional accuracy, good heat transfer |
| Machinery manufacturing | Machined parts, automotive components | Excellent machinability, consistent dimensions |
| Hydraulic systems | Hydraulic lines, fuel lines | Smooth internal bore, low fluid resistance |
| Industrial piping | General industrial pipe systems | Balanced overall performance, cost‑effective |
This material has good workability and weldability, making it suitable for moderate‑load applications. The 10–76 mm OD range is the most typical supply size for GOST 8734 cold‑drawn seamless pipes.
7. Quality Assurance and CBAM Compliance Support
Quality Assurance:
Each batch is supplied with a complete MTC (Mill Test Certificate).
EN 10204 3.1/3.2 certificates are available upon request.
Third‑party inspections by SGS, BV, TÜV, etc. are supported.
Full traceability from melt number to finished product.
CBAM (Carbon Border Adjustment Mechanism) Compliance Support:
We can provide product‑specific carbon emission data based on actual site measurements.
Assistance in preparing monitoring plans, emission reports, and other verification documents.
Help you avoid the EU default value penalty mechanism.
8. Why Choose Sanon Pipe Industry?
| Our Strengths | Details |
|---|---|
| Standards expertise | Deep understanding of the GOST 8733/8734 system; accurate interpretation of Russian technical requirements |
| Material integrity | Complete certificates for Steel 20; we can also provide equivalent GB/ASTM/JIS grade documentation |
| Precision guaranteed | Production strictly follows GOST 8734‑75 tolerance requirements – reliable accuracy |
| Fast delivery | Backed by a 20,000‑tonne standing inventory; urgent orders shipped in 7–15 days |
| Full‑service support | One‑stop service from inquiry, background check, quotation, documentation, to logistics |
| Zero‑risk commitment | Over 240 internal control checkpoints; zero document discrepancy rate |
9. Contact Us
Sanon Pipe is dedicated to providing high‑quality GOST‑compliant cold‑drawn seamless steel pipes to customers in Russia, the CIS, and beyond. Whether you need standard sizes or custom dimensions, we offer professional technical support and flexible supply solutions.
Typical specification description example:
Труба стальная бесшовная холоднодеформированная 57×3.5 ГОСТ 8734-75 / В 20 ГОСТ 8733-87
(Cold‑drawn seamless steel pipe 57×3.5, in accordance with GOST 8734‑75 dimensional standard, material Steel 20, per GOST 8733‑87 technical conditions)
SANONPIPE
+86 22 58658800
info@sanonpipe.com
www.sanonpipe.com
High Standards · Fast Delivery · Zero Risk · Green & Low Carbon
Post time: Jun-26-2026
