How to visually distinguish whether hot-rolled or cold-drawn seamless pipe?

To distinguish whether it is a hot-rolled carbon seamless pipe or a cold-drawn carbon seamless pipe simply from the appearance, we need to distinguish from the following steps:

1. In terms of length
The length of cold-drawn seamless steel pipe is generally shorter than that of hot-rolled seamless steel pipe. The longest cold-drawn seamless steel pipe can reach 9 meters, while the longest hot-rolled seamless steel pipe can reach more than 12.5 meters, and the longest thermal expansion length can reach 14 meters.

2. Wall thickness
Cold-drawn seamless steel pipes have a thicker wall than hot-rolled seamless steel pipes. The partial wall condition of cold drawn seamless steel pipe is not non-existent but very small. For example, the maximum partial wall condition of the wall thickness of 3mm is 0.3mm, while the minimum partial wall condition of hot rolled seamless steel pipe is 0.3mm. Generally, the partial wall condition of hot rolled seamless steel pipe is 0.3mm. The wall range is 10%, that is, the wall thickness of 10mm can be offset to plus or minus 1mm (9mm-11mm) to be qualified.

3. Appearance
Cold-drawn seamless steel pipes are very beautiful after annealing, while hot-rolled steel pipes do not show such advantages over cold-drawn seamless steel pipes, and their appearance is dull.

4. In terms of price
Generally, the price of cold-drawn seamless steel pipe is 200-300 more expensive than that of hot-rolled seamless steel pipe (different sizes).