Pan head, countersunk and washer-head cross recessed screws in 3,684 part numbers, M1 to M10. Insulated assemblies run PA66 nylon, brass and polycarbonate under GB 818 and GB 819, while the stainless range rides on the Yuebiao YB 818 standard, whose heads run smaller than the national spec and whose sizes reach down to M1. DIN 967 captive-washer heads and the slotted GB 65 / 67 / 68 legacy patterns fill out the metal range in 304 and 316 stainless and 1010A carbon steel, with lengths from 2 to 200 mm. Working below M2? The M0.9–M2 micro screw guide maps every stocked length.
