Description

Special-shaped steel pipe are seamless steel pipes made of various special shapes by cold drawing. Special-shaped seamless steel pipes are the general term for seamless steel pipes with other cross-sectional shapes except round pipes.

According to the different cross-sectional shapes and sizes of steel pipes, they can be divided into equal wall thickness special-shaped seamless steel pipes, unequal wall thickness special-shaped seamless steel pipes, and variable diameter special-shaped seamless steel pipes.

Special-shaped steel pipes can be divided into elliptical special-shaped steel tubes, triangular special-shaped steel pipes, hexagonal special-shaped steel tube, diamond-shaped special-shaped pipes, octagonal special-shaped tubes, semicircular special-shaped steel circles, unequal hexagonal steel special-shaped pipes, five-petal plum blossom-shaped special-shaped steel pipe, double convex special shaped steel pipes, double concave steel special-shaped pipes, steel melon seed-shaped special-shaped pipes, conical special-shaped steel pipes, and corrugated special-shaped steel pipes.

Special-shaped seamless steel pipes are widely used in various structural parts, tools and mechanical parts. Compared with round tubes, special-shaped tubes generally have larger moments of inertia and section modulus, and greater bending and torsional resistance, which can greatly reduce the weight of the structure and save steel.

Applications of Special-shaped Steel Pipes:

Special-shaped steel pipes are widely used in building structures, machinery manufacturing, automotive transportation, energy equipment, aerospace, and decoration engineering due to their advantages such as high bending and torsional strength, lightweight, and material saving.

1. Building and Structural Engineering: Special-shaped steel pipes are used as curtain wall joists, space frame node pipes, steel structure beams and columns, handrails, solar panel supports, etc., to improve load-bearing efficiency and reduce self-weight (e.g., square and rectangular tubes, elliptical tubes).

2. Machinery and Tool Manufacturing: Special-shaped steel pipes are used to manufacture frames, drive shafts, hydraulic cylinders, agricultural machinery frames, and precision parts, utilizing their high moment of inertia to optimize stiffness (e.g., hexagonal tubes, irregularly shaped cold-drawn tubes).

3. Automotive and Rail Transportation: Special-shaped steel pipes are applied to chassis components, exhaust pipes, high-speed rail bogie components, and body reinforcement components to achieve lightweight design (some are variable cross-section BJ type).

4. Energy and Chemical Equipment: Special-shaped steel pipes are used in boiler superheaters, nuclear reactor guide pipes, and oil/chemical pipelines (especially heat-resistant alloy shaped pipes such as 12Cr1MoV type).

5. Aerospace and High-end Equipment: Used in aircraft landing gear, rocket supports, ship keels, and other parts with stringent strength-to-weight ratio requirements (often seamless shaped pipes).

6. Decorative and Daily Hardware: Stainless steel shaped pipes (triangular, trapezoidal, U-shaped, etc.) are used in handrails, display racks, furniture, and bathroom accessories, balancing aesthetics and structural function.

Production Range	Outer Diameter:6-530mm (0.24 inch – 21.18 inch)
Production Range	Wall Thickness:0.8-200mm (0.03 inch – 7.89 inch)
Material / Grade	Carbon Steel: GB/T 3094: 10#, 20#, 35#, 45#, 55#, Q235B, Q235C, CF53, A105 ASTM A519: 1010, 1020, 1026, 1035, 1045, 1050 DIN17121/EN 10297-1, DIN1629/DIN2391/EN 10305-1: C10/CK10, C22/CK22, C35/CK35, C45/CK45, CF53 JIS3441/JIS3444/JIS3445: STKM11A, STKM12A/STKM12B/STKM12C, STKM13A/STKM13B/STKM13C JIS G4051: S10C, S20C, S25C, S35C, S45C, S55C
Material / Grade	Alloy steel : GB/T 3094: 16Mn(Q345B), 20Cr, 40Cr, 15CrMo, 20CrMo, 28CrMo, 30CrMo, 35CrMo, 42CrMo, 20CrMnTi, 40MnMoV, 20Mn2, ZF6, 16MnCr5 20MnCr5, 38Mn2V, 09CrCuSb(ND) ASTM A519: 5120, 5140, 4130, 4135, 4140 DIN17121/EN 10297-1, DIN1629/DIN2391/EN 10305-1: ST52, EN10084-1998 20Cr4, 41Cr4, 15CrMo4, 25CrMo4, 35CrMo4, 42CrMo4, 16MnCr5 JIS3441/JIS3444/JIS3445: SCM432/SCRRM3, SCM4 JIS G4053: JIS SCr420, JIS SCr440, SCM415, SCM420
Tolerance	Can be customized according to customer’s requirements
Technique	Cold Drawn / Cold Rolled
Shape	Triangle, Hexagon, Square, Rectangle, Octagon, Lemon Pipe and Others can be customized
Further Processing for Steel Tubes	Cutting, Chamfer, Threading, Inner diameter or Outer Diameter Lathe, Surface Shot Blasting, Laser Marking