Worm screw and wormwheel have "ZI" profile with involute section, granting a higher efficiency and lower friction loss.
The material chosen for manufacturing SITI worm screws is casehardened steel 20MnCr5.
The working schedule requires heat treatment, which gives a superficial hardness of 60 Hrc, the worm screw is then subjected to a grinding process.
The material used for the wormwheel is centrifuged B-14 bronze. The teeth are manufactured by special automatic cutting machines by means of specific class "A" tools, according to DIN 3968 specifications.
From size I 60 onwards, taper roller bearings are standard on the input shaft.
Strength to outer radial and axial loads on the input shaft is largely improved.
SITI worm gearboxes are projected to last at least 10,000 working hours.
A high viscosity synthetic oil provides lifetime lubrication without any type of intervention.
The use of pressure die cast aluminium housing of a very modern design characterize sizes from I 30 to I 80, while cast iron is still used for the bigger units.