1. Process classification
Square steel pipe according to the production process: hot rolled seamless square pipe, cold drawn seamless square pipe, extrusion seamless square pipe, welded square pipe.
The welded square pipe can be divided into
(a) By process: arc welding square pipe, resistance welding square pipe (high frequency, low frequency), gas welding square pipe, furnace welding square pipe.
(b) According to the welding line - straight seam welded square pipe, spiral welded square pipe.
2. The material classification
Square steel pipe according to the material: carbon steel square pipe, low alloy square pipe.Common carbon steel is divided into :Q195, Q215, Q235, SS400, 20# steel, 45# steel, etc.Low alloy steel is divided into Q345, 16Mn, Q390, ST52-3, etc.
JIS G3466-88 Japanese general structural rectangular tube fitting range standard can be implemented.
3. Folded section shape classification
Square pipes are classified by section shape
(1) Simple cross section square tube -- square tube, rectangular tube.
(2) Complex cross - section square pipe: flower - shaped square pipe, open - shaped square pipe, corrugated square pipe, shaped square pipe.
4. Folding surface treatment classification
Square steel pipe according to the surface treatment: hot galvanized square pipe, electric galvanized square pipe, oil coated square pipe, pickling square pipe.
Classification of folding USES
Square steel pipes are classified by use -- square pipes for decoration, for machine tools, for mechanical industry, for chemical industry, for steel structure, for shipbuilding, for automobile, for steel beam and column, for special purpose.
5. Folding wall thickness classification
Square pipes are classified by wall thickness - super - thick - wall, thick - wall and thin - wall.
2)Hot dip galvanized:Z260-520g/m2
|Steel material||Q195 → Grade B, SS330,SPHC, S185
Q215 → Grade C,CS Type B,SS330, SPHC
Q235 → Grade D,SS400,S235JR,S235JO,S235J2
Q345 → SS500,ST52
|Standard||BS1387, EN10297, BS6323, BSEN10217, GB/T13793-1992,
GB/T14291-2006, GB/T3091-1993, GB/T3092-1993,
GB3640-88, ASTM A53/A36, EN39/EN10219, API 5L,
|Technique||Electronic Resistance Welded (ERW )
Electronic Fusion Welded (EFW)
Double Submerged Arc Welded (DSAW)
|Welded Line Type||Longitudinal|
3)Thread with Coupling or cap
|End protector||1) Plastic pipe cap
2) Iron protector
|Surface Treatment||1) Bared
2) Black Painted (varnish coating)
4) With Oiled
5) 3 PE, FBE, corrosion resistant coating
|Inspection||With Hydraulic Testing, Eddy Current , Infrared Test|
|Class A test pressure||4.83MPa-13.10Mpa|
|Package||1.Big OD:in bulk
2.Small OD:packed by steel strips
3.woven cloth with 7 slats
5.as per customer's option
|Application||construction structure, machinery making, container, hall structure, sun seeker, offshore oil field, sea trestle, motorcar cassis, airport structure, shipbuilding, automobile axle pipe and so on.|
2) Bulk carrier
|Port of Shipment||Qingdao Port,Tianjin Port, China|
|Date of Delivery||According To The Quantity And Specification Of Each Order|
|Addition||Special design available according to requirment
Anti-corrosion and high-temperature resistant with black painting
All the production process are made under the ISO9001:2000 strictly