OEM/ODM Factory Rectangular Hollow Section Steel Tubes Size: 50mm - Black Annealed Cold Rolled Square Tube For Steel Furniture And Structure – Baowusteel company

Cold Rolled Square Tube material is cold rolled carbon steel strap with wall thickness 0.6mm to 2.0mm. When cold-rolled steel strap is heated to the annealing temperature, the surface color will turn black due to high temperature contact with air, which is called black stripping. The physical properties become soft, which is convenient for further welding to make steel pipes. The common hardness is 57HRB, and it can also be reduced to different hardness as needed.

Differences between “black annealed cold rolled square tube” and “hot rolled square tube”

	Black annealed cold rolled square tube Raw material is cold rolled steel straps, then is heated (annealing) . Diameter 15mm-80mm Wall thickness 0.6mm-2mm Widely used for steel furniture, chair, desk, table, bed frame, steel structure
	Hot rolled square tube Raw is hot rolled steel straps, not heated. Diameter 20mm-400mm Wall thickness 2mm-20mm Used for construction, steel post.

OD (mm)	OD (inch)	OD (mm)	OD (inch)
15x1516x1618x18 19×19 20×20 25×25 30×30 38×38 40×40 45×45 50×50 55×55 60×60 65×65 70×70 75×75 80×80	0.59”x0.59”0.63”x0.63”0.71”x0.71” 0.74”x0.74” 0.8”x0.8” 1”x1” 1.2”x1.2” 1.5”x1.5” 1.6”x1.6” 1.8”x1.8” 2”x2” 2.2”x2.2” 2.4”x2.4” 2.5”x2.5” 2.8”x2.8” 3”x3” 3.2”x3.2”	15x2020x25 20×30 20×40 25×50 30×60 40×60 40×80	0.59”x0.8”0.8”x1”0.8”x1.2” 1.2”x1.6” 1”x2” 1.2”x2.4” 1.6”x2.4” 1.6”x3.2”

Application
The cold rolled square tube is widely used for furniture and steel structure frame, such as steel desk, table, chair, steel bed, shelf,gym equipment.

Loading and packing
Package: 1. In bundle, tied with steel straps, no other package.
2.In bundle, wrapped with plastic cover,tied with steel straps, each end with nylon straps.
Loading:
Loading by container for thin wall thickness tubes.
Sometime put small diameter tube into big diameter tube to save container space.

FAQ
1. To get an exact price, please send us below details for your inquiry:
(1) Thickness
(2) OD (out diameter0
(3) Tube legnth
(4) Slightly oiled surface , or dry surface
(5) Quantity

2. What kind of package will I get?
Generally it will be standard exporting package. We can supply the package according to customers’ requirement.
Find more information from “packing & shipping” item above.

3. What’s the differences between “cold rolled” and “cold rolled black annealed”?
The cold rolled black annealed steel coil will go through heating, while “cold rolled steel coil” will not heat again.

4. About the “oiled” surface .
Oiled surface is to prevent the steel from getting rust. While not all customers want the oiled surface. Generally we supply the product without oiled surface.

5. Customized Requirement.
Product is available customized on thickness, OD, surface coating thickness, logo printing, packing. As each requirement is customized, so please contact our sales to get exact answer.

6.Do you supply sample?
Yes, we provide sample. Generally sample is free of charge.
While international courier isn’t free. We will return the courier cost once we cooperate.
Sample will be sent by air courier when weight less than 1kg.