For Inside measurement or inner diameter of holes, The standard micrometer , known as outside micrometer, might be used to measure the outer diameter of a hole, bolt, There are many type of inside one. like single rod, caliper type.

Features:  

     Ratchet stop

     One Stationary and one movable caliper mounted on a tube,

     Adjustable caliper.

     Range: 5-30mm 25-50mm 50-75mm, 75-100mm

 

 Specification:

Order No	Range(mm)	Resolution(mm)	Remarks
IM-120	5-30	0.01
IM-220	25-50	0.01
IM-320	50-75	0.01
IM-420	75-100	0.01
IM-121	0-1	0.01
IM-221	1-2	0.01
IM-321	2-3	0.01
IM-421	3-4	0.01