QuickJack 5300013 Pinch-Weld Block SetQuickJack 5300013 Pinch Weld Block Set Dimpled Urethane Engages Pinch Weld Rails The QuickJack 5300013 Pinch Weld Block Set are urethane rubber blocks with a pinch weld design and are perfect for vehicles with pinch weld frames. The harder rubber offers extra support for pinch weld type vehicles. These blocks fit with all QuickJack frame assemblies. Sold in sets of four. Supporting cars on pinch weld rails creates excessive pressure points which can