Material inspection, performance checks, and tests for seamless steel tubes should include the following.

(1) During the inspection of seamless steel tubes, if any of the following conditions are encountered, a verification check should be conducted.

The certificate does not match the furnace number or steel grade of the seamless steel tubes upon arrival.

② No steel grade or heat number markings on pipes or signboards.

③ In case the certificate lacks full chemical composition or mechanical properties, additional tests must be conducted for the missing items.

(2) Specifications for seamless steel tube verification inspection.

All seamless steel pipes should be measured individually for their outer diameter, wall thickness, and length, with dimensions conforming to the specifications of relevant standards.

All seamless steel tubes should be individually numbered and hardness tested.

③ From each batch of seamless steel pipes, select one with high hardness and one with low hardness. Prepare 5 specimens for each, including 2 for tensile tests, 2 for impact tests, and 1 for flattening or cold bending test. The testing methods and evaluation criteria shall comply with the relevant national regulations.

④ Take samples from seamless steel pipes or specimens used for mechanical property tests for chemical analysis.

In the absence of a non-destructive testing (NDT) certificate from the manufacturer, each item should be individually inspected for NDT compliance. Even with a manufacturer's NDT certificate, if defects are found during visual inspection, 10% of the batch should be randomly sampled for testing. If any non-compliant items are found, a thorough inspection of each item is required.