The crusher spring is the tension element in a jaw crusher's pull-back rod assembly — it keeps the toggle plate firmly seated in the toggle block and ensures proper crusher operation. LIMING manufactures heavy-duty coil springs from high-quality spring steel with precise load-deflection characteristics.
In a jaw crusher, the toggle plate sits between the swing jaw and the frame toggle block. To keep the toggle plate properly seated during the crushing cycle — and to pull the swing jaw back during the return stroke — a pull-back rod connects the swing jaw to the frame, tensioned by a heavy coil spring. This spring maintains constant pressure on the toggle plate assembly, preventing it from lifting out of its seat during operation.
The crusher spring also plays a critical role in the safety system. When the toggle plate breaks during an overload event, the spring tension pulls the swing jaw back to its rest position, clearing the obstruction. Once the toggle plate is replaced, the spring automatically re-tensions the new plate, and the crusher is ready to restart. Without a properly functioning spring, the toggle plate may not seat correctly, leading to uneven wear, noise, and potential failure.
A worn or fatigued crusher spring loses its tension, causing toggle plate chatter, increased wear on toggle seats, and reduced crushing efficiency. LIMING's crusher springs are manufactured from high-quality silicon-manganese spring steel (60Si2MnA) with precise heat treatment to ensure consistent spring force and long fatigue life under the demanding cyclic loading of crusher operation.
The crusher spring operates under continuous cyclic loading — compressed and released with every revolution of the eccentric shaft (typically 250-300 RPM). This makes fatigue resistance the most critical material property:
| Material | Tensile Strength (MPa) | Yield Strength (MPa) | Fatigue Life | Best For |
|---|---|---|---|---|
| 60Si2MnA (Silicon-Manganese Spring Steel) | ≥1,275 | ≥1,177 | Excellent — designed for cyclic loading | Standard crusher springs (most common) |
| 50CrVA (Chrome-Vanadium Spring Steel) | ≥1,275 | ≥1,128 | Outstanding — superior fatigue resistance | Heavy-duty, high-cycle applications |
| 65Mn (Manganese Spring Steel) | ≥980 | ≥785 | Good — adequate for lighter duty | Small crushers, lower cycle rates |
60Si2MnA is the industry-standard material for crusher springs, offering an excellent balance of tensile strength, elasticity, and fatigue life at a reasonable cost. For extremely demanding applications — such as large primary crushers operating continuously at high throughput — 50CrVA provides superior fatigue resistance due to its vanadium alloying, which refines the grain structure and improves toughness.
Premium spring steel, precise heat treatment, and accurate load ratings.
60Si2MnA and 50CrVA wire from certified mills — consistent chemistry for reliable spring performance.
Controlled quench and temper produces the optimal combination of hardness, elasticity, and fatigue life.
Each spring is load-tested to verify deflection at working load. Consistent tension for proper toggle operation.
Common spring sizes stocked. Custom specifications produced in 10-20 days.
| Parameter | Specification |
|---|---|
| Product Type | Heavy-duty coil tension spring for toggle plate assembly |
| Material | 60Si2MnA (standard), 50CrVA (heavy-duty), 65Mn (light duty) |
| Spring Type | Helical compression spring (cylindrical) |
| Wire Diameter | 8 mm – 50 mm (per crusher model) |
| Outer Diameter | 60 mm – 300 mm (custom) |
| Free Length | 200 mm – 800 mm (per design) |
| Active Coils | 4-12 (per load requirement) |
| Total Coils | 5.5-14 (including end coils) |
| End Configuration | Both ends closed and ground flat |
| Working Load | Custom per crusher model (typically 2-20 kN) |
| Spring Rate | Calculated per crusher specifications |
| Surface Treatment | Phosphate coating, paint, or galvanized (optional) |
| Heat Treatment | Quench and temper to HRC 42-48 |
| Compatible Crushers | PE/PEX series and equivalent jaw crushers |
| Lead Time | 10-20 days (stock sizes ship immediately) |
From spring steel wire to load-tested finished product — every step controlled for consistent quality.
Spring steel wire coiled to specified diameter, pitch, and coil count on CNC spring coiling machines.
Initial heat treatment relieves coiling stresses and stabilizes the spring geometry.
Both ends ground flat and perpendicular to the spring axis for uniform load distribution.
Hardening heat treatment achieves HRC 42-48 — optimal for fatigue resistance and elasticity.
Each spring load-tested at working deflection. Surface treatment applied and final inspection completed.