New inspection items for rivets: the diameter of the rivet body, the length of the rivet body, the thickness of the rivet cap and its cap diameter, the total length of the core, the exposed specification of the core, the specification of the screw, and the diameter after installation can be considered. In the specific detection, accurate measurement can be carried out for the weak points of commodities, such as tensile strength, shear stress, and anti stripping force of nail core. It is important to pay attention to the bolts, such as insufficient riveting enough, timely riveting of wood, or the large rivet core sun visor, which makes the branch pipe of riveting body unable to pull down; there are also jumping heads, aluminum iron core pulling rivets, that is, the pulling force of the rivet core is too low or the fracture specification is too small. There are 5 series products of 2.4 3.2 4 4.8 5 6.4. The length of rivet core is 11 series products 6-8-8.5-9.5-11-12-12.5-13-14.5-15.5-16-18-21. There are many odd numbers in China. The sales market length is 22-25-30-40 At present, the 3.2 diameter of stainless steel plate can guarantee the length of 16mm (I saw that some manufacturers had already made 3.2 * 20 mm, and the length of 28 mm was guaranteed overseas, but it has not been seen.) 4. The diameter can guarantee the length of 25 mm and the diameter of 4.8 can guarantee the length of 40 mm, but it is generally not used, The similar diameter of 6.4 and 4.8 can ensure that the 40mm long closed flat round head rivet (gb12615) can be sold in the market At the present stage, the quality level of metal drawing bolts for double drum rivets is generally 4.8 * 10 / 14, 6.4 * 14 / 16 / 19, and that of formelac nails is 6.4 * 14 / 17 / 19 / 21. The specification of single / double drum / multi drum and general bolt difference is not [write this paragraph] and the characteristic level specification of pull rivet is divided into 06.08 There are 15 grades including 10 11 12 20 21 22 23 30 40 41 50 51. The open type rivet can be divided into two types according to the top of the head.