Progessive plug is made to save time, it has both the Go and Nogo gage on the same member.
Trilock gages are designed and best used for plugs with a diameter over 1", they are reversible. The Trilock feature is the source for the name of this design. The handle has three prongs on the ends, which fit into three grooves equally spaced around the central hole of the gage member.
The Taperlock gage is named because of the tapered shank, which locks into the tapered hole in the end of the handle. Available for gages up to 1 1/2", depth stops available upon request. As a further aid in identification, the Go and Nogo members have a different length of gaging surface. It is permissible to make the Nogo gage shorter because it is not supposed to enter the part.
The Reversible plug gage has the advantage that it can be reversed and used at the opposite end when one end becomes worn and goes out of tolerance.
The gaging members are simple pins that can be removed from the handle by loosening the collet nuts at the ends. Extra long members are available.