Plain limit gauge is a common name for a plug-shaped cylindrical gauge.
Also known as a plain gauge, it is used to check the accuracy of the hole and the inner diameter and pilot diameter of the internal thread.
Both GO and NO GO sides are passed, which ensures the accuracy of the hole and the inner diameter.
Accuracy cannot be guaranteed if only one is inspected.
In addition, the plain gauge for holes and the plain gauge for the inner diameter of the internal thread are separate products with different applications.
| GO Side |
|
NO GO side |
|---|
If it passes, it passes.
If you go through it, you can see that the hole is larger than the gauge dimensions. |
If it stops, it passes.
By stopping*1, it can be seen that it is made smaller than the gauge dimensions.
|
|---|
* The definition of "stop" in NO GO gauge differs depending on the type of gauge. Please refer to the list of how to use each type of plug gauge below.
* The photo is a limit plane gauge. Inner diameter plug gauges are used in a similar way, but the objects to be inspected and the accuracy are different.
List of how to use spigot gauges by type
the gauge symbol
OSG Product Name
(Model number) |
JIS Type
(Thread standard) |
Precision Examples: |
Machining/Inspection |
JIS
|
How to use |
|---|
| |
|
|
|
|
NO GO side |
GO side
|
|---|
| Inner Diameter Plug Gauge (LG) |
Current JIS
（M）
|
6H, etc.
|
No distinction
|
PP
|
Stop at least one pitch
|
To pass through without difficulty (penetration)
|
|---|
Foremer JIS(M)
|
Class 2, etc.
|
machine
|
WM
|
Don't get through (it's good if you can get through)
|
inspection
|
IM
|
Former JIS(U)
|
2B, etc.
|
handicraft
|
WM
|
inspection
|
IM
|
Limit Plane Gauge (PG)
|
Current JIS
|
H7, etc.
|
No distinction
|
-
|
Don't go in
|
Passing through (penetration)
|
|---|
