Coefficient inspection of steel structure bolts

Code for acceptance of steel structures (GB 50205) clearly stipulates that the manufacturer and the installation unit shall carry out anti sliding test and re inspection respectively (clause 6.3.1). The anti sliding coefficient must be greater than or equal to the design value.
Inspection of anti sliding coefficient of high strength bolt connection pair in steel structure
(Yongnian fastener steel structure high strength bolt connection pair)
In the inspection of engineering data, many construction sites only have the test report of anti sliding coefficient of the manufacturer in the factory, but lack the retest report of the anti sliding coefficient of the test pieces provided to the construction site.

The anti sliding coefficient inspection shall be based on the manufacturing batch of steel structure bolts, with each 2000t of single project as a manufacturing batch, and those less than 2000t shall be regarded as a batch. When two or more surface treatment processes are selected for the friction surface of components in single project, each surface treatment process shall be inspected. Three groups of test pieces per batch.
The conventional treatment methods of friction surface mentioned in GB 50017-2003 include sand blasting (shot), coating inorganic zinc rich paint after sand blasting (shot), red rust after sand blasting (shot), etc.
It should be specially pointed out that: the anti sliding coefficient of many projects is very high, and the actual component friction surface treatment is very poor, which can not meet the anti sliding coefficient required by the design requirements; or the friction surface required by the design is coated with inorganic zinc rich paint after sandblasting (shot), while the submitted one is not painted (the friction coefficient is reduced after painting). For projects with large value of anti sliding coefficient design, if such situation is found by on-site supervision, rectification must be ordered and the friction surface after treatment shall be retested, otherwise serious quality risks may be left.
The company's main business: high strength bolt, high strength nut, steel structure bolt, steel structure nut, grid sealing plate, grid bolt, etc.