中文版When the thread accuracy requirement is high, besides labels the thread code number, but should also label the thread tolerance tolerance zone code number and the thread turns on lathe gathers the length.
The thread mark's labelling form is:
The thread code number - - thread tolerance zone code number (pitch diameter, goes against diameter) - - to turn on lathe gathers the length
l) the tolerance zone code number adds the letter expression by the digit (box thread with capital letter, external screw thread with lowercase letter), like 7H, 6g and so on, should point out specially, 7H,6g and so on represents the thread tolerance, but H7, g6 represents the circular cylinder common difference code number.
2) turns on lathe gather the length stipulation short to (with the S expression), (with the N expression), long (with the L expression) three kinds. In the ordinary circumstances, does not label the thread to turn on lathe gathers the length, its thread tolerance zone according to medium turns on lathe gathers the length (N) to determine. When necessity, but the replenishment turns on lathe gathers length code number S or L, like “M20-5g6g-L”. When special need, may indicate turns on lathe gathers the length the value, like “M20-5g6g-30”.
Plain thread
Ordinary coarse thread: The characteristic code number M+ nominal diameter + gyrotropic + thread tolerance zone code number (pitch diameter, goes against diameter) - - to turn on lathe gathers the length
Ordinary fine thread: The characteristic code number M+ nominal diameter * pitch + gyrotropic + thread tolerance zone code number (pitch diameter, goes against diameter) - - to turn on lathe gathers the length
The right-hand thread abbreviation does not pour, the laevo rotatory uses “LH” to express.
M the 16-5g6g expression coarse plain thread, the nominal diameter 16, the dextrorotation, thread tolerance zone pitch diameter 5g, great diameter 6g, turns on lathe gathers the length according to the medium length consideration.
M16×1 the LH-6G expression fine thread plain thread, the nominal diameter 16, the pitch 1, the laevo rotatory, the thread tolerance zone pitch diameter, the great diameter are 6G, turns on lathe gathers the length according to the medium length consideration.
Pipe thread labelling
The form is: The characteristic code number (column pipe thread indicated with G that circular cone pipe thread uses the NPT expression) + the size code number + grade of tolerance code number + gyrotropic
G1A--LH expressed that the British system non-thread seal pipe thread, size code number 1, the dextrorotation, the grade of tolerance is a level.
Rcl/2 expresses the inch thread seal awl pipe thread, size code number 1/2, the dextrorotation.
