Products
Wholesale OEM 3 Leaf Spring Forgings for Trailer Suspension
With unwavering precision during manufacturing, our 3 leaf springs meet the highest quality standards and are engineered to withstand even the harshest road conditions. Rigorous quality control checks guarantee their reliability and longevity. Truecasteng offer the complete product range for spring, truck suspension, steering, driveline, coupling, and hitch product lines. These parts are unmatched in their material, quality and operation. You can find everything you need under one roof.
Colour: Original / Black
Materials: Spring Steel /52CrMnMoV
Production Processes: Hot Rolling / Forging Process
Heat Treatment: Normalizing, Annealing, Quenching, Tempering
Surface Finish: Shot Blasting, Polishing, Baking Varnish
Certificates: IATF16949
Transport Package: Wooden Case
Delivery Time: 15-20 Days
1. Product Introduction
The 3 leaf spring is a critical elastic component in a vehicle’s suspension system. Consisting of three curved spring steel plates of varying lengths, it is mounted between the vehicle frame and the axle. Its primary function is to transfer the load between the wheels and the frame, absorb shocks from uneven road surfaces, and minimize vehicle vibration. Backed by Truecasteng’s extensive expertise in driveline and suspension systems, every spring is engineered to deliver reliable stability and handling in the toughest driving conditions.
| Product Name | Wholesale OEM 3 Leaf Spring Forgings for Trailer Suspension |
| Working length (L) | 64.6″ [1639 mm] |
| Front end length (L1) | 25.8″ [655 mm] |
| Rear end length (L2) | 25.8″ [655 mm] |
| Total weight | 237.6lb /108 KG |
| Number of leaves | 3 |
| Tensile Strength(MPa) | ≥1400 |
| Yield Strength(MPa) | ≥1200 |
| Impact (J) | ≥45 |
| Hardness (HB) | 380-430 |
| Total thickness(H) | 3.38″ [86 mm] |
| Free camber height(H1) | 2.95″ [75 mm] |
| Spring Eye diameter(D) | 2.36″ [60 mm] |
| Bush in diameter (D1) | 0.96″ [24.5 mm] |
| Width (W) | 5.0″ [127 mm] |
| Materials | 51CrV4/52CrMoV4/60CrMo3-3 |
| Production Processes | Hot Rolling/ Forging Process |
| Certificates | IATF 16949 |
| Heat Treatment | Normalizing, Quenching, Tempering |
2. 3 Leaf Spring Key Features
- High Load & Fatigue Resistance: Manufactured from premium spring steel (e.g., SUP9, 5160H, 60Si2Mn) for exceptional yield strength and a long fatigue lifecycle.
- Precision Heat Treatment: Scientifically controlled quenching and tempering processes ensure the perfect balance of toughness and hardness.
- Surface Enhancement: Double-sided shot peening effectively relieves residual surface stress, significantly extending the lifespan of the spring.
- Superior Anti-Corrosion: Treated with E-coating (Electrophoretic deposition) or premium eco-friendly anti-rust paint for excellent resistance against corrosion and salt spray.
- Quiet & Anti-Friction Design: Equipped with anti-friction interleaf inserts or noise-reduction treatments to improve ride comfort.
3. Manufacturing Process
Truecasteng strictly adheres to the IATF 16949 quality management system. Our core manufacturing processes include:
- Blanking & Piercing: CNC precision cutting for exact dimensional consistency.
- Eye Rolling & Forging: High-temperature heating followed by precise eye forming at the ends.
- Heat Treatment: Full high-temperature quenching + medium-temperature tempering for core mechanical properties.
- Shot Peening: High-speed steel shot blasting to maximize fatigue limits.
- Assembly & Presetting: Assembled with a center bolt and subjected to load presetting tests to prevent future sagging or deformation.
- Surface Coating: Anti-rust E-coating and top-coat painting.
- Final Inspection: Rigorous testing for camber height, stiffness/spring rate, and random fatigue life sampling.
The Half extra heavy-duty 5 inch wide leaf springs. Accurate spring alignment preserved by the use of rugged spring guides on the trunnion casting.
A split trunnion casting permits easy maintenance and replacement of trunnion bushings. Axle alignment and realignment made possible by adjustable plates within the spring-end boxes. One adjustment plate on each axle is welded at the factory. After axle alignment is completed, the installer welds the other adjustment plate to ensure sustained axle alignment.
For increased life and flexibility, thick rubber pads are used above the spring leaves in the axle boxes. This construction permits greater twist freedom in the spring box a standard flexibility feature that reduces wear and promotes better ride characteristics.
These products are inspected internally at Truecasteng for their dimensioning and material properties, among other things. If so desired, destructive, non-destructive or microstructural analysis can also be performed.
In addition the components are delivered to the customer for evaluation. The customer can test the product for functionality, dimensions, strength, appearance and various other important parameters. Based on the results, it is determined whether the product is ready to be produced in series or if additional technical adaptations need to be implemented. High product quality is safeguarded by means of this intensive evaluation phase, as is a stable production process and a high degree of delivery reliability.
4. 3 Leaf Spring Applications
- Commercial Vehicles: Light Commercial Vehicles (LCV), medium-duty trucks.
- Trailers: Utility trailers, boat trailers, agricultural trailers, and RV chassis.
- Passenger Vehicles: Pick-up trucks, SUV aftermarket suspension upgrades.
- Specialty Vehicles: Small mining transport vehicles, auxiliary construction machinery.
5. Matching Parts (One-Stop Sourcing)
To ensure peak suspension performance, Truecasteng also provides a complete range of matching fasteners and chassis components:
- U-Bolts: High-tensile standard bolts to securely lock the spring to the axle.
- Shackles & Brackets: Heavy-duty supports that allow the spring to flex safely.
- Bushings: High-quality polyurethane or rubber bushings for wear resistance and noise reduction.
- Center Bolts: Precision carbon steel bolts to prevent leaf slippage.
- Spring Pins: Case-hardened pins designed to work seamlessly with shackles.
6. Purchasing Considerations for Buyers
When sourcing or placing an order, please verify the following parameters to ensure perfect fitment and performance:
- Dimensions: Provide exact measurements, including Eye-to-Eye Length, Leaf Width, Thickness of each leaf, and Free Camber/Arch height.
- Material Grade: Confirm the steel grade (e.g., SUP9 is highly recommended for its cost-to-performance ratio) based on your market’s load and environmental demands.
- Eye Type: Specify the eye configuration (e.g., Berlin eye, upturned, or downturned) and the inner diameter for bushing fitment.
- Load Capacity: Clearly define the rated load capacity per axle or per spring to prevent premature failure due to overloading.
- MOQ & Lead Time: Confirm requirements for custom sampling, Minimum Order Quantities (MOQ), and mass production delivery schedules.
Partner with industry-leading precision casting experts to bring your vision to life. We specialize in delivering custom, high-quality casting solutions. With years of experience, cutting-edge technology, and an unwavering commitment to excellence, we ensure every component exceeds your expectations.