Disadvantages of seamless tubing are following below:

Crack 

(Inclusions cracks caused; perforated surface peeling unclean crack; grain crushing cracks) 

Port injustice 

(The last time length, there is no cut pipe ends flat, sloping or port causing incomplete resection.) 

Glitch 
(When the pipe length, with after cutting machine, the port will be left a lot of the same metal as the thorn fragments, no nozzle after sanding deburring.) 

Residual surface oxide 
(Since the last pickling improper handling, surface oxide residues have specific shape or sporadic massive overall surface color is black dot; reason for pickling pickling operation or improper time.) 

Stains 
(Air-dried after cleaning the tube is not timely; before a no clean, appeared after the second road cleaning, and this defect can not be eliminated by wiping.) 

Pits 
(In the drawing process, due to lubricant mixed with debris, resulting in small pits after the drawing surface; such as pipes in the lifting process, and equipment to produce collision pits.) 

Flat mouth 
(Tubes in the lifting process collided with other devices, resulting in flat mouth; For the last step for the drawn steel pipe, cut pipe end resection amount is too small.) 

Surface nap 
(A drawing process at the end of the tube, and the resulting drawn cracking; peeling is not clean, is amplified in the production process, the final product appears nap.) 

Straightening India 
(Pipe inspection before packaging needs straightening, in straightening process, improper operation, etc., will stay clear of straightening printed on standard pipe, spiral. Mostly in the factory iron roller straightening iron roll surface rough.) 

Surface rust 
(Improper placement of the tube after the finished product, or surface treatment is not appropriate.) 

Surface stains 
(Pipe to the oil is not clean before annealing, after annealing leads to the pipe surface stains heavier; Furthermore, in product testing, the tubes come into contact with oil and other stains, resulting in the tube surface is dirty.) 

Scratch the surface 
(Tubes in the final production steps or finished product testing in contact with a hard object caused, and because operators do not operate sparse, causing the pipe surface scratches.) 

Polishing imprint 
(If the tube is polished tube, and then the polishing process, the polishing speed is too fast or more curved tubes, etc., will leave a mark on the tube surface, flat shape.)