**TOTAL DIAMETRAL CLEARANCE**

The difference between the throat diameter and the
tube diameter.. Tolerances of the throat diameter and the tube
diameter determine the maximum and minimum total diametral
clearance gap. These values divided by 2 will give the radial
maximum and minimum gaps.

The **THROAT (BORE) DIAMETER** must be calculated using
the minimum clearance gap given in **Figure 21** and the
maximum clearance gap as shown in **Figure 23**.

The throat (bore) diameter can be calculated by adding the
minimum clearance gap. **(Fig. 20)** to the maximum tube
(rod) dimension. This will give the minimum throat dimension.
The maximum throat dimension can be obtained by adding the
maximum gap **(Fig. 22)** to the minimum type (rod)
dimension.

By using this method, it allows the use of softer compounds
without the possibilities of extrusion.