WH Series Round Wire Coil Springs - 30% Deflection

WH-series round-wire coil springs with 30% deflection are used in injection mold tooling where controlled force and repeatable shock absorption protect precision components during cycling. In automotive connector and housing molds, they help maintain stable return action for small ejecting or actuated mechanisms, reducing load variation that can affect part dimensional stability.

They are also well-suited for industrial machinery mold assemblies that experience vibration and frequent open/close cycles. The round-wire form supports smoother loading and reliable reset under cyclic stress, which supports consistent damping and reduces the risk of chatter or uneven actuation.

For test fixtures and modular tooling, the selectable spring constant (2.9 to 14.7 N/mm) and maximum load range (4.9 to 441.3 N) allow engineers to tune the force to the mechanism’s allowable deflection window (20–30%). This variant’s designed deflection ratio alignment improves force predictability at the target travel.

The provided metadata does not specify the steel grade or any heat-treatment state (e.g., quench & temper, nitriding). For accurate material selection in high-cycle mold environments, confirm the spring material specification from the supplier documentation tied to the selected spring constant (2.9, 5.9, 9.8, or 14.7 N/mm) and size (D 4–27 mm; L 5–100 mm).

In general spring steel selection trades off hardness and wear resistance against toughness to manage fatigue life. Higher hardness can improve resistance to set and surface wear, while reduced toughness may increase sensitivity to shock loading and stress concentration.

• Verify target hardness (HRC) and fatigue design basis for cyclic tooling use.
• Confirm heat treatment (pre-hardened vs. quenched & tempered) to ensure dimensional stability at operating temperatures.
• If multiple materials are offered, compare fatigue strength and expected relaxation rate under your deflection ratio (20–30%).

Selection is driven by the required stiffness and allowable travel. Start by matching your mechanism’s intended travel to the specified allowable deflection ratio of 20–30%. For this product variant, the design target is 30% deflection, so choose the operating point close to this value to maintain predictable force.

Next, match the load requirement using the spring constant: choose from 2.9, 5.9, 9.8, or 14.7 N/mm. Then verify the corresponding maximum load needs fall within 4.9 to 441.3 N to avoid under-design (insufficient force) or overloading (premature fatigue/setting).

• Check geometry: outer diameter D = 4–27 mm and free length L = 5–100 mm.
• Ensure installed length leaves adequate stroke margin for your compression at 30% deflection.
• Where space is constrained, prioritize D first (spring clearance) and then L (available travel), while accounting for any assembly tolerances in seat alignment.