What is the thickness deviation of seamless pipes

1.International standards
According to international standards, the allowable thickness deviation of seamless steel pipes should be between plus and minus 12.5%. That is to say, if the thickness of seamless steel pipes is 10 millimeters, the allowable deviation range should be 1.25 millimeters, which is between 9.75 millimeters and 11.25 millimeters.
2. Domestic standards
The domestic standard divides the thickness range of seamless steel pipes into four levels, namely A, B, C, and D. The allowable deviation range is as follows:
The allowable deviation of A-grade pipes is within plus or minus 10%;
The allowable deviation of B-grade pipes is within plus or minus 8%;
The allowable deviation of C-grade pipes is within plus or minus 6%;
The allowable deviation for D-grade pipes is within plus or minus 5%.