Aluminum.
Rim flanges, steel.

Aluminum bright.
Steel electro zinc-plated.

Standard AT-profile with metric pitch (trapezoidal toothing). At least one toothed belt pulley must have a rim flange. The toothed belt pulleys have a center bore or are pre-drilled (this can vary due to production methods). For this reason, the dimension D2 max. given in the table is the maximum diameter of the bore that the toothed belt pulleys are supplied with. This pilot hole/centre bore can be customised with a reamed hole, reamed hole with keyway or a tapped hole by the customer. Alternatively, bushings can be fitted by the customer to reduce the diameter.
To reduce weight, the toothed belt pulleys may have a recess on one face.