GB/T 8162 10 Seamless Steel Tubes for Structural Purposes, GOST 8732-75, EN 10297-1, JIS G3441, JIS G3444, JIS G3445, 10, 15, 20, 25, 35, 45, 20Mn, 25Mn, Q345A, Q345B, Q345C, Q345D, Q345E, Q390A, Q390B, Q390C, Q390D, Q390E, Q420A, Q420B, Q420C, Q420D, Q420E, Q460C, Q460D, Q460E, Q500C, Q500D, Q500E, Q550C, Q550D, Q550E, Q620C, Q620D, Q620E, Q690C, Q690D, Q690E, 40Mn2, 45Mn2, 27SiMn, 40MnB, 45MnB, 20Mn2B, 20Cr, 30Cr, 35Cr, 40Cr, 45Cr, 50Cr, 38CrSi, 20CrMo, 35CrMo, 42CrMo, 38CrMoAl, 50CrVA, 20CrMn, 20CrMnSi, 30CrMnSi, 35CrMnSiA, 20CrMnTi, 30CrMnTi, 12CrNi2, 12CrNi3, 12Cr2Ni4, 40CrNiMoA, 45CrNiMoVA

GB/T 8162 Seamless Steel Tubes for Structural Purposes

Standard: GB/T 8162
Equivalent Standard: EN 10297-1, JIS G3441, JIS G3444, JIS G3445

Material: 10
Equivalent Material: 1010, E235, St35.8, St37

Chemistry Composition

C, %	Si, %	Mn, %	Cr, %	Ni, %	S, %	P, %	Cu, %
0.07-0.14	0.17-0.37	0.35-0.65	0.15 max	0.30 max	0.040 max	0.035 max	0.30 max

Mechanical Properties

Tensile Strength, MPa	Yield Strength, MPa	Elongation, %
353 min	216 min	24 min

Outside Diameter & Tolerance

Type of Steel Pipes	Allowable Deviation
Hot Rolled Steel Pipe	±1%D or ±0.5, whichever is greater
Thermal Expansion Steel Pipe	±1%D or ±0.5, whichever is greater
Cold Drawn Steel Pipe	±0.75%D or ±0.3, whichever is greater
Cold Rolled Steel Pipe	±0.75%D or ±0.3, whichever is greater

Wall thickness & Tolerance

Type of Steel Pipes	Outside Diameter, D	S/D	Allowable Deviation
Hot Rolled Steel Pipe	≤102mm	-	±12.5%S or ±0.40mm, whichever is greater
	>102mm	≤0.05	±15%S or ±0.40mm, whichever is greater
		>0.05~0.10	±12.5%S or ±0.40mm, whichever is greater
		>0.10	+12.5%S/-10%S
Thermal Expansion Steel Pipe	-		±15%S

Type of Steel Pipes	Wall Thickness, S	Allowable Deviation
Cold Drawn Steel Pipe	≤3	+15%S/-10%S or ±0.15mm, whichever is greater
	>3~10	+12.5%S/-10%S
	>10	±10%S
Cold Rolled Steel Pipe	≤3	+15%S/-10%S or ±0.15mm, whichever is greater
	>3~10	+12.5%S/-10%S
	>10	±10%S

Length

The typical length of the steel pipe is 3000mm~12000mm. After negotiation with clients, other lengths can be supplied.

Fixed length or multi-length is not more than 6000mm	+30/-0mm
Fixed length or multi-length is greater than 6000mm	+50/-0mm

Straightness

Steel Pipe Wall Thickness, mm	Curvature per Meter, mm/m
≤15	≤1.5
>15~30	≤2.0
>30 or D≥351	≤3.0

The full-length curvature of the steel pipe should not exceed 0.15‰ of the total length.

GB/T 8162 specifies the order content, size, shape, weight, technical requirements, test methods, inspection rules, packaging, marking and quality certificate of seamless steel pipes for structural use. GB/T 8162 is applicable to seamless steel pipes for mechanical structures and general engineering structures.
GB/T 8162规定了结构用无缝钢管的订货内容、尺寸、外形、重量、技术要求、试验方法、检验规则、包装、标志和质量证明书。GB/T 8162适用于机械结构和一般工程结构用无缝钢管。

Order should include standard, product name, steel grade, size, quantity (total weight or total length), delivery condition, special requirements.

The burrs at the end of the steel pipe should be removed.

Steel should be smelted by electric arc furnace plus external refining or oxygen blown converter plus external refining. The tube billets can be manufactured by continuous casting, die casting or hot rolling.

Steel pipes shall be manufactured by hot rolled, thermal expansion, cold drawn or cold rolled methods.
Hot rolled and thermal expansion steel pipes are delivered in the delivery condition of hot rolled, thermal expansion or heat treated. Cold drawn and cold rolled steel pipes shall be delivered in an annealed or high temperature tempered delivery condition. According to the contract, cold drawn and cold rolled steel pipes can also be delivered in cold drawn, cold rolled or other heat treated delivery condition.

There should be no visible cracks, folds, scars and delamination on the inner and outer surfaces of the steel pipes. These defects should be completely removed, the removed depth should not exceed the lower deviation of the wall thickness, and the actual wall thickness at the cleaned area should not be less than the minimum value allowed of the wall thickness. Other local defects not exceeding the deviation under the wall thickness are allowed to exist.

Type of inspection or test	Frequency of Testing
Chemical analysis	One sample per heat number
Tensile test	One sample on each of the two steel pipes per lot
Hardness test	One sample on each of the two steel pipes per lot (for alloy structural steel pipes with a wall thickness of not less than 5mm and delivered in annealed or high temperature tempered delivery condition)
Impact test	Three samples on each of the two steel pipes per lot (for low alloy high strength structural steel pipes with an outside diameter of not less than 70mm, and a wall thickness of not less than 6.5mm)
Flattening test	One sample on each of the two steel pipes per lot (for steel pipes in grades 10, 15, 20, 25, 20Mn, 25Mn, Q345, Q390, with an outside diameter D>22~600mm, and S/D ratio not greater than 10%)
Bending test	One sample on each of the two steel pipes per lot (for steel pipes with an outer diameter not greater than 22mm)
Ultrasonic test	Each pipe
Eddy current test	Each pipe
Magnetic flux leakage detection	Each pipe, can be replaced by eddy current test
Dimension and shape	It should be measured with a measuring tool that meets accuracy requirements
Inner and outer surfaces	It should be visually inspected under sufficient lighting conditions

Lot rule

Each lot should be composed of steel pipes of the same grade, the same heat number, the same specification and the same heat treatment system (furnace). The quantity is as follows:

The outside diameter is not greater than 76mm, and the wall thickness is not greater than 3mm: 400 pieces;

Outside diameter is greater than 351mm: 50 pieces;

Other sizes: 200 pieces;

If the number of remaining steel pipes is not less than 50% of the above-mentioned rule, they should be listed as a separate lot. In case less than 50% of the above-mentioned rule, it can be merged into adjacent lot of the same grade, the same heat number, and the same specification.

According to user requirements, steel pipes can be delivered by galvanizing. The galvanized layer on both inner and outer surfaces should be completed, and there should be no black spots and bubbles that are not plated with zinc, small rough surfaces and local zinc tumors are allowed. The surface of the steel pipe can be passivated after galvanizing. The inner and outer surfaces of the steel pipe galvanized layer should be visually inspected under sufficient lighting conditions.

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