88. Graphical symbols that shows the type of screw
The method of representing threads has been stipulated in the JIS standards. The following table lists the types of threads and the symbols affixed at the beginning when expressing those threads.
| Method of representation | Type of thread | Symbol expressing the type of thread | |
|---|---|---|---|
|
A thread whose pitch is expressed in mm |
Metric coarse thread |
M |
|
|
Metric fine thread |
|||
|
Miniature thread |
S |
||
|
Metric trapezoidal thread |
Tr |
||
|
Thread whose pitch is expressed by the number of ridges |
Unified coarse thread |
UNC |
|
|
Unified fine thread |
UNF |
||
|
Tapered pipe thread |
Male tapered thread |
R |
|
|
Female tapered thread |
Rc |
||
|
Parallel female thread |
Rp |
||
|
Parallel pipe thread |
G |
||