I normally go with the settings of:

40lb/ft stg 1
60lb/ft stg 2
75lb/ft stg 3

but please bear in mind that this is with a 150mm long 12.9 rated m10 cap head bolt. i prefer to use these as they are re-usable as they are not stretch bolts but cost about the same as a stretch bolts
they normally cost about 12 quid a set up here in the north-east 1.50 a bolt