The angular head require the positioning block for a firm and rigid fixing.
This block is assembled on the machine tools by 2 screw and a taper pin.
The positioning pin is thrusted by its spring and fits itself in the V-housing of the positioning block.
After this, you have to tighten the pin blocking screws, the positioning pin doesn't have play.
Repeat the head loading procedure to test the correct positioning.

Head Type	O	P	R	Item
TOM "0"	65	15	26	2000080
TOM "2.3"	70	27	26	2200080
TOM "1/90"	65	15	26	2000080
TOM "4/90"	100	19	30	2400080
TOM "0/90"	65	15	26	2000080