Wrapped Bushing Dimensional Inspection
Rolled products in the manufacturing process determine the existence of open joints, making products in the free state not habe a good whole circle shape, while sleeve diameter and the seat for the interference fit between the holes, sleeve adapted to maximize Block hole shape can not be directly measured in the free state the inner/outside diameter of the product only can be by a special measuring instrument; In ISO3547 standards measured Part 2 of the rolled products made clear tolerance test requirements, including:
Test Method A: Huff regulatory test outside diameter;
Test method B: use stop-pass gauge to test the outside diameter;
Test method C: use stop-pass gauge to test the inside diameter;
Test method D: Measure the outer diameter of large scale product and use wallthickness test to replace test method C. (Wall-thickness test and test method C can not be used at the same time.)
External diameter test methods:
Test A of ISO 3547 Part 2
Check the outside diameter of a wrapped bush using measuring equipment as shown to the right, with a checking block consisting of upper and lower halves and setting plugs, at a determined checking load of Fch, during the test the outside diameter of the bush is made smaller by the elastic reduction, however it is not a permanent deformation. The bushes outside diameter can be calculated from the difference in the value of z ( Z).
Test B of ISO 3547 Part 2
The test is carried out with two ring gauggs, a Go gauge and a No Go gauge whose diameter Shall be chosen empirically from with Table 6 of ISO3547-1:1999 and agreed upon. It shall be possible to press the bushes into the GO gauge and then push them through with hand pressure (maximum force 250N). On the other hand with the same force, it shall not be possible for them to go into and through the NO GO gauge (See ISO 12307-1).