8615921639636



—— Product Center ——

Quality builds brands, technology strengthens capabilities,

global development is achieved together.



Location: HOME > PRODUCTS > Carbon steel > Carbon Steel Pipe > GB/T 8162-2018 Seamless steel tubes for structural

GB/T 8162-2018 Seamless steel tubes for structural

GB/T 8162-2018 Seamless Steel Pipes for Structural Use: Applicable to general structures, mechanical structures, building structures, bridges, supports, mechanical parts, and other load-bearing applications. Not applicable to pressurized fluid transportation (fluid pipes are specified in GB/T 8163).
Main Export Materials: 10#, 20#, 45#, Q355B (formerly Q345B)



Contact Us

GB/T 8162-2018 (Seamless Steel Tubes for Structural Purposes, implemented 2019-02-01) National Standardization Administration

Scope of Application: Applicable to general structures, mechanical structures, building structures, bridges, supports, mechanical parts, and other load-bearing applications. Not applicable to pressurized fluid transportation (fluid pipes are specified in GB/T 8163).

Main Export Materials: 10#, 20#, 45#, Q355B (formerly Q345B)

Material Introduction:

10# Steel (High-quality low-carbon structural steel): Extremely low carbon content, excellent plasticity, toughness, and cold workability; easy to bend, stamp, and weld.

Relatively low strength; mostly used for structural components with low loads, high toughness, and frequent cold working (such as supports, lightweight components, and mechanical parts).

20# Steel (Most common export grade): Medium-low carbon high-quality carbon steel; balanced strength, plasticity, toughness, and weldability.

Most mainstream export material; suitable for building structures, mechanical structures, ordinary components, and general load-bearing applications.

45# Steel (Medium Carbon High-Quality Structural Steel): Medium carbon steel with high strength and hardness; performance can be improved by tempering/quenching.

Used for shafts, gears, high-strength structural components, mechanical parts, and other structures requiring high strength.

Q355B (Low Alloy High-Strength Steel): Microalloyed (Mn-V-Nb), approximately 30% stronger than 20# steel, with good low-temperature toughness.

Suitable for heavy-duty structures, large buildings, bridges, engineering machinery, and high-load-bearing components.

Product Name		Carbon steel pipe/tube
More materials		20#, Q235B, A53B, S235JR, STPG38,A106B, P235GH, STB410,L245/L360, API 5L X42/X52/X60/X65, Gr.B, A333 Gr.1/Gr.6,Q355B, S355JR, A572Gr50
Best-selling specifications	Seamless pipe	20#, Q355B, A106B	6-630	1–18
	ERW straight seam welded pipe	Q235B, A53B	21-323	2.8–6
	Spiral welded pipe	Q235B, L245, X52	219-1220+	6–25
	Square tube	Q235B、Q355B、S235JR	20×20-200×200	1.5-10
	Rectangular tube	Q235B、Q355B、S235JR	20×40-150×300	1.5-10
Length		6/12m（Current inventory on hand and ready for use）, Length can be customized
Surface treatment		Black Pipe，Varnish / Anti-rust Paint，Anti-rust Oil / Preservative Oil，Sand Blasting / Shot Blasting，Hot Dipped Galvanized，Painting / Coating
Delivery Condition		Hot Rolled / Hot Rolled Seamless (HR), Cold Drawn / Cold Drawn (CD), Normalized / N, Annealed / A, Quenched and Tempered / Quenched and Tempered (QT)
Standard		ASTM, AISI, JIS, GB, DIN, EN, etc.
Surface		Black, Bright Polished, Rough Turning, Matt Surface Treatment, No. 4. BA, etc.
Scope of Application		Common applications for stainless steel pipes include food processing,Textile operations, Breweries, Water treatment plants, Oil and gas processing,Fertilizers and pesticides, Chemical applications,Construction, Pharmaceuticals, Auto parts, etc.
Certificate		ISO, SGS, BV, etc.
Production Technology		Hot Rolling, Cold Rolling
Edge Processing		Edging, Trimming

Hot-selling specifications:

20#: Φ48×3.5 (scaffolding), Φ60×4, Φ76×4, Φ89×4.5, Φ114×5, Φ168×8

45#: Φ50×5, Φ80×6, Φ100×8, Φ120×10 (shafts/machinery parts)

Q355B: Φ121×6, Φ159×8, Φ219×10, Φ273×12, Φ325×12 (heavy-duty structure)

Delivery condition: Hot rolled (black skin), Cold drawn (bright), Normalized, Annealed (on demand)

Chemical composition (mass fraction %)

Brand	C	Si	Mn	P ≤	S ≤	Cr ≤	Ni ≤	Cu ≤
10#	0.07~0.14	0.17~0.37	0.35~0.65	0.035	0.035	0.15	0.25	0.25
20#	0.17~0.24	0.17~0.37	0.35~0.65	0.035	0.035	0.25	0.25	0.25
45#	0.42~0.50	0.17~0.37	0.50~0.80	0.035	0.035	0.25	0.25	0.25
Q355B	≤0.20	≤0.50	1.00~1.60	0.030	0.030	-	-	-

Mechanical properties

Grade	Tensile strength σb (MPa)	Yield strength σs (MPa)	Post-rupture elongation A(δ5) ≥ (%)	Impact test
10#	335~475	≥205	24	-
20#	410~550	≥245	20	-
45#	540~670	≥335	14	-
Q355B	490~665	≥325	21	≥34J（Room temperature）

Statistics on the popular models and common specifications of carbon steel pipes

Standard model	Common outer diameter range (mm)	Common wall thickness series	Common length
ASTM A53 Gr.B	21.3～610	SCH40、SCH80、STD	6m / 12m
ASTM A106 Gr.B	21.3～610	SCH40、SCH80、STD、XS	6m / 12m
API 5L Gr.B / X42 / X52	114～1422	SCH40, STD, XS, Customized wall thickness	6m / 12m
GB/T 8163 20#	10～630	SCH40, SCH80, Standard wall thickness	6m / 12m
EN 10216 P235TR1	17.2～610	SCH40, S235, Standard wall thickness	6m / 12m
JIS STPG370 / STPG410	15～600	SCH40, SCH80, Standard wall thickness	6m / 12m

Select materials based on application

For general fluid transportation (water, gas, oil): 20#, Q235B, A53 Gr.B, STPG370

The best cost-performance ratio, globally applicable

For high-temperature / steam / boiler pipes: A106 Gr.B, 20G, 15CrMoG, P235TR1/P235GH

Better resistance to high temperature and pressure

For oil and gas pipelines: API 5L Gr.B, X42, X52, X60

High strength and good toughness, suitable for long-distance pipelines

For low-temperature environments (cold storage, LNG support): A333 Gr.1/Gr.3, 16MnDG

Resistant to low temperature without cracking

For structural pipes (supports, machinery, steel structures): Q355B (old 16Mn), St44.2, A36

High strength and good load-bearing capacity

Our Advantages:

Professional manufacturer of carbon steel pipes with years of export experience.

Full standards: GB, ASTM, API 5L, EN, JIS available.

Complete sizes: OD 12.7–711mm, SCH40/SCH80/STD/XS.

Strict quality control with MTC, accept SGS/BV inspection.

Stable production & fast delivery.

Competitive price for bulk orders.

Export Packaging:

Steel strips bundling + plastic pipe caps.

Anti-rust oil + woven bag for sea transportation.

Wooden pallet & container reinforcement available.

Standard shipping marks for custom clearance.

Payment Methods

Flexible payment terms available: T/T and L/C. For new clients, 30% advance payment for production, balance against copy of B/L. L/C is acceptable for large & regular orders to secure both parties.

Previous:A572 Grade 50 Carbon Structural Steel Coil

Next:GB/T 5310 Boiler Pressure Pipe

Warehousing Management

Before each batch of steel leaves the factory, a complete process inspection is strictly carried out. From chemical composition, mechanical properties to dimensional tolerance and surface quality, each item is carefully checked to ensure compliance with national standards and export regulations. At the same time, the quantity, packaging and rust prevention treatment are also verified. An original factory warranty certificate is attached, guaranteeing the quality. Before shipment, inspection photos are provided. Any non-compliant items will not be released, and the quality is fully controllable throughout the process. This ensures your overseas purchasing is safe and worry-free.

All items are visually inspected before delivery. No cracks, deformation, rust, scratches or cutting marks are allowed; edges must be smooth. Only visually sound products will be shipped.

Thickness, width, length, wall thickness, outer diameter have been measured. Straightness, curvature, torsion, diagonal tolerance all meet the corresponding tolerance requirements.

Quality inspection includes: mechanical property tests (yield strength, tensile strength), elongation rate, impact energy, hardness testing, chemical composition testing, process performance testing, etc.

Inspection according to packaging requirements: secure binding, moisture-proof film, rust-proof paper, export fumigation/fumigation-free wooden crates, shipping marks, gross weight, net weight, etc.

We will provide full reception services to support the customers' on-site inspection of the goods.

Hot Rolling Production Line

Cold rolling precision processing

Cold drawing/cold rolling line

Hot Rolling Production Line

Hot rolling production line (producing hot-rolled coils/medium-thick plates, thickness 2–60mm)

Cold rolling precision processing

(Producing ultra-thin / high-precision / shiny panels, with thickness ranging from 0.1 to 3mm, for high-end products)
Cold drawing/cold rolling line

(High-precision cold-drawn round steel, square steel, hexagonal steel, and special-shaped bars)

Cold drawing/cold rolling line

(High-precision cold-drawn round steel, square steel, hexagonal steel, and special-shaped bars)

Warehousing Management

A ten-thousand-ton standardized warehouse with grid-based zoning and system positioning enables rapid material retrieval and reduces the time spent searching for materials.

Inbound inspection: Verify the physical items against the inbound form, inspect the appearance, dimensions, and labels. Once confirmed to be correct, the materials are entered into the ERP system and processed for storage.

Logistics and Global Delivery: Self-operated fleet + contracted logistics partners; expedited service available for urgent orders.

International Shipping: Supports FOB, CIF, DDP, and other trade terms, covering 100+ countries and regions.

Process: Booking → Trucking → Customs Declaration → Loading onto Ship/Aircraft → Bill of Lading Issuance → Document Delivery → Destination Port Customs Clearance (Optional) → Last-Mile Delivery.

Provides door-to-door one-stop logistics with full tracking to ensure safe and timely arrival of goods.

After-Sales Service and Traceability: Delivery receipts, logistics information, and quality inspection documents are sent to customers within 24 hours of shipment.

Established a full product lifecycle traceability system, allowing tracking of production, quality inspection, warehousing, and transportation records.

Follow-up inspection within 72 hours of arrival; rapid response and handling of quality issues; assistance in resolving customs clearance issues for foreign trade orders.

Packaging Method