SDS Drills are available in three sizes: SDS Plus (10mm), SDS-Top (14mm) and SDS-Max (18mm). These sizes relate the size of the shank.
SDS-Plus:
This drill has a 10 mm shank with two open grooves held by the driving wedges and two closed grooves held by locking balls. This is the most common size and takes a hammer up to 4 kg. The wedges grip an area of 75 mm² (0.116 sq in) and the shank is inserted 40 mm into the chuck.
SDS-top:
This drill has a 14 mm shank similar to SDS-plus, designed for hammers from 2 to 5 kg. The grip area is increased to 212 mm² (0.329 sq in) and the shank is inserted 70 mm. This size however, is not particularly common.
SDS-max:
This drill has an 18 mm shank with three open grooves and locking segments rather than balls. It is designed for hammers over 5 kg. The wedges grip an area of 389 mm² (0.603 sq in) and the shank is inserted 90 mm.
