Indicating type. the measuring element is a torsional leaf spring. clockwise tightening (with trailing pointer) and anticlockwise tightening. with 1/4" internal hex drive (f 6. 3 din 3126). comparative scale in in·lb and cursor. inserts and adaptors with external hex e 6. 3 (1/4"). DIN 3126/iso 1173 are securely held and firmly controlled in the mounting shaft . to attach 1/4" sockets, please order adaptor no 3115 . certificate in accordance with din en iso 6789-2:217