Stamped shackles are commonly used on Harken Small Boat Blocks and are suitable for lower loads. For handling heavier loads, it is recommended to opt for forged and high-resistance shackles instead. This particular shackle features a 6mm/1/4 inch pin and a ring for easy attachment. Consider using forged and high-resistance shackles for heavier loads. Shackle pin: (mm) 6 mm Shackle pin: (in) 1/4 in Weight (g) 15.5 g Weight (oz) 0.54 oz A (mm) 17 mm A (in) 11/16 in B (mm) 16 mm B (in) 5/8 in Maximum working load (kg) 680 kg Maximum working load (lb) 1500 lb Breaking load (kg) 1360 kg Breaking load (lb) 3000 lb 6mm Stamped Shackle Part No. 138