Stamped shackles are used on most Harken Small Boat Blocks and are appropriate for low loads. For higher loads, select forged and high-resistance shackles instead. These 5mm Shackles are used on 57mm Ratchet and Ratchmatic Blocks. Weight (g) 8 g Weight (oz) 0.29 oz Shackle pin Ø (mm) 5 mm Shackle pin Ø (in) 3/16 in Maximum working load (kg) 567 kg Maximum working load (lb) 1250 lb Breaking load (kg) 1134 kg Breaking load (lb) 2500 lb A (mm) 12 mm A (in) 1/2 in B (mm) 11 mm B (in) 7/16 in