The role of the common thread of the screw

Ordinary coarse thread: feature code M + nominal diameter + rotation direction + thread tolerance zone code (pitch diameter, top diameter)-screwing length.

Ordinary fine thread: feature code M + nominal diameter * pitch + rotation direction + thread tolerance zone code (pitch diameter, top diameter)-screwing length.

Right-hand thread is omitted, and left-hand thread is indicated by "LH".

16-5g6g means coarse general thread, nominal diameter 16, right-handed, thread tolerance zone 5g middle diameter, 6g major diameter, the screw length is considered as medium length.

M16×1 LH-6G means fine-tooth ordinary thread, nominal diameter 16, pitch 1, left-handed, thread tolerance zone, both the middle and major diameters are 6G, and the screwing length is considered as medium length.