Each spring features a back bend design at both ends, ensuring the spring stays securely in place. The springs are precision machine-cut for accurate and consistent sizing, with clean cuts, no burrs, and resistance to rust. This sofa spring repair kit is designed to connect zigzag-shaped, non-recessed springs to a wooden frame on upholstered furniture, ideal for seat or rear support applications. Made from carbon steel and heat-treated for enhanced elasticity and durability, each spring features a 48mm high arch and 25mm short spacing, providing strong support with reinforced material feet. Restore sagging cushions and reinforce your furniture frame with this reliable repair solution. Repairing your sofa or chair helps extend furniture life, offering a cost-effective alternative to replacement. These springs are the same quality used in commercial and custom furniture manufacturing.