In this schematic the "Bolt,housing" is used most often.
The most reasonably priced component used on the Gsf600 1999 (x) (e02 E04 E17 E18 E22 E25 E34) / P37 Rear Caliper is the Bolt.
Some items from this specific schematic: Cap,bleeder Plug, Clip,pad Pin, Bolt,housing, Seal Set,piston.