... transmission line and other power line . The insulator can be mounted rigidly on supporting structure by means of a bolts ... clamp top with vertical or horizontal mounting. Cantilever strength can be 5KN, 10KN, 12.5KN, 16KN. Main type: ... 57-1, 57-2, 57-3, 57-4, 57-5, 57-11, 57-12, 57-13, 57-14, ... -15, 57-21, 57-22, 57-23, 57-24, 57-25, 57-31, 57-32, 57-33, ... C29.7 , IEC383 and BS137. 57-5 line post insulator