1. Insert the unit and roughly adjust as for type ‘R’.
2. Using a hexagon wrench, tighten the retaining screw to fully compress the spring stack and back-off ¹⁄₂ turn max.
3. Obtain final size by adjusting the dial only. Do not change the retaining screw setting.
   • When adjusting for a smaller diameter, always adjust under-size and then adjust clockwise to size.
   • ‘TR’ units are supplied with retaining screw and spring stack assembled in the correct order.
   • In the event that the spring stack becomes separated from the retaining screw and needs to be fitted, always remember that the disc spring nearest the unit should be with its outer rim towards the unit and other disc springs alternating as illustrated.
4. This will ensure that the outer rim of the disc spring seats against the counterbore in the back of the boring bar (note: the number of disc springs varies with the unit size).

In extreme cutting conditions i.e. interrupted cuts etc. the action of the ‘TR’ unit can be made more rigid by re-stacking these disc springs, i.e. double stacking, but note that this will halve the adjustment range and must be pre-loaded by backing off the retaining screw only ¹⁄₄ turn (or less).

Additional disc springs may have to be purchased to achieve this. 'TR' units, as supplied are fitted with:

For flexibility of use, the ‘TR’ unit can be used as for the standard ‘R’ unit, i.e. by fully tightening the retaining screw. In this way, the ‘TR’ unit becomes only marginally less rigid than the standard ‘R’ unit but will reduce the effective life of the disc springs that lose their spring characteristics after sustained full compression.