1.Application scope: Used for threaded joints between thin metal (aluminum, copper) parts and thicker metal parts (main body), wood panels, wall surfaces, etc.. Must be used with the corresponding specifications, slot type
screw spigot with.
2. Reference standard
Pan head cross slot GB845, ISO7049
Countersunk head cross slot GB846, ISO7050
Umbrella head cross slot GB847, ISO7051
Japanese JISB1125 and American ANSI/ASME B18.6.4 have various head types.
3. head type: the same as the head type of self-tapping nails. New and old national standards have three head types: the old national standard for round head (R), countersunk head (F) and half countersunk head (O), the new national standard has a pan head (P), countersunk head (F) and half countersunk head (O). American
Machine Screws have a variety of head types, in addition to the commonly used pan head, countersunk head, half countersunk head in addition to large flat head, hexagonal
Washer head, Warwick head, etc.
(3), tooth type: generally common A teeth and AB teeth. The new version of the IFI standard has been eliminated A tooth products, but due to market needs, some companies are also producing A tooth products, more domestic with A tooth. A tooth AB tooth products are mainly different in the number of teeth, generally speaking, A tooth for coarse teeth, AB tooth for fine teeth, but A tooth and AB tooth products also have differences in tooth outside diameter and head diameter size.