1. It is necessary to check whether the appearance of the Non-standard custom nut is uniform. If there are any undesirable phenomena such as whitening, blackening, and smearing, do not buy it. Choose products with uniform appearance and normal color;

2, the groove part of non-standard screws needs to be noted that if the screw groove is shallow or burrs, the inner diameter of the screw is rough, etc., this will affect the work efficiency of the installer, so if this situation occurs, it is not necessary to consider the manufacturer's products ;

3. If the non-standard custom nut has eccentric head pain, tilted head, not round or plump head, burrs, and whether there is headshot or crack in the head, this kind of nut cannot be purchased, because it will lead to broken heads. , forming the serious consequences of the entire product mold (title: the mother of industry) being scrapped. Non-standard screws are indispensable industrial necessities in daily life: tiny screws used in cameras, glasses, clocks, electronics, etc.; general screws for televisions, electrical products, musical instruments, furniture, etc.; as for engineering, construction, and bridges. Use large screws and nuts; transport equipment, aircraft, trams, automobiles, etc. use both large and small screws.