25.002 mm (Go) and 24.977 mm (No Go)
The "Go" and "No Go" sizes for a snap gauge like 25H7 indicate the acceptable dimensional limits for a specific feature on a workpiece. In the case of the 25H7 snap gauge, the numbers "25" and "H7" refer to a specific tolerance class and size.
In the ISO system for fits and tolerances, the number before the letter represents the basic size of the hole or shaft, and the letter indicates the tolerance class. In this case:
- "25" is the basic size.
- "H7" is the tolerance class for the hole.
Feeler gauge
Feeler gauges are used:
– To check the gap between the mating parts
– To check and set the spark plug gaps
– To set the clearance between the fixture (setting block) and the cutter/tool for machining the jobs
– To check and measure the bearing clearance, and for many other purposes where a specified clearance must be maintained.
Either "Soft linen cloth" or "Chamoise leather"
Grade - 2
Slip gauges are graded according to their accuracy as Grade 0, Grade I and Grade II.
Grade 0 is used in laboratories and standard room which serves as standard for periodically checking the accuracy of Grade I and Grade II gauges.
Grade I is of higher accuracy and used in inspection departments.
Grade II is intended for use in workshops during the actual production of components, tools and gauges.
