Limit Gauges For Screw Thread
To determine thread standard and class of screw thread limit gauges, threads are tested by the two limit method GO and NO GO system. For the NO GO side there is a specified JIS method and standard, but no ISO classification.
|
Screw thread to beinspected |
ISO |
Current JIS |
|||
|
Gauge type |
Symbol |
Gauge type |
Symbol |
||
|
External thread
|
Pitch diameter |
GO screw ring gauge
NO GO screw ring gauge |
GR
NR |
)GO screw ring gauge
NO GO screw ring gauge formachinework
NO GO screw ring gauge for inspection |
GR
WR
IR |
|
Majordiameter |
Plain GO ring gauge for major diameter
Plain NO GO ring gauge for major diameter
Plaincallipergauge for major diameter |
R GO
PR NO-GO
PC |
Limitsnapgauge formachinework
Limit snap gaugefor inspection |
WS
IS |
|
|
Internal thread
|
Pitch diameter |
GO screw plug gauge
NO GO screw plug gauge |
GP
NP |
GO screw plug gauge
NO GO screw plug gauge for machine work
NO GO screw plug gauge for inspection |
GP
WP
IP |
|
Minor diameter |
Plain pulg gauge for minor diameter |
PP |
Limitpluggauge formachinework
Limitpluggauge for inspection |
WM
IM |
|
Mutually related positions of external screw thread and internal screw thread limit
gauge and gauge for checking explanation figure.
Example M3x0.5 for ISO 6H 6g and current JIS class Ⅱ .
