A heavy-duty extension spring featuring an internally threaded metal end plug on one end and a loop hook on the other, combining bolt-grade rigid fixing with precise elastic tension for high-load industrial applications.

Hot-wound from large-diameter high-tensile spring steel, this spring delivers exceptional load-bearing capacity under heavy tension. Its defining feature is the precision-machined internally threaded metal end plug, which connects directly to bolts or threaded rods, eliminating the hook disengagement risk common in standard springs under heavy loads. The opposite loop-hook end enables quick connection to mating hardware. Zinc plating provides reliable outdoor corrosion protection, and the robust overall construction is purpose-built for high-frequency, heavy-duty working conditions.