This main spring provides the primary clamping force for the tine assembly on a cultivator. It sits between the frame and the tine arm, holding the tine in its working position against the soil load. When the spring loses tension or breaks, the tine fails to return to its set depth after passing over an obstacle, leading to uneven tillage. The spring is designed to match the original coil geometry so that the preload and working deflection are identical to the factory assembly. A matching auxiliary spring is available separately to complete the pair.