Heavy-Duty 7-Blade 40" Semi-Elliptical Leaf Spring (70x10mm)

The Heavy-Duty 7-Blade 40" Semi-Elliptical Leaf Spring (70x10mm) is an industrial-grade trailer suspension component engineered to provide heavy payload support, lateral axle stability, and controlled shock absorption for commercial transport trailers, agricultural implements, plant machinery carriers, and heavy-duty chassis. Built with an extra-wide 70 mm blade width by 10 mm individual blade thickness arranged across a 7-blade graduated stack, this suspension assembly is designed specifically to handle demanding commercial payloads and severe dynamic axle loads across corrugated gravel tracks, rough rural terrain, and high-speed highway routes.

Featuring an extended 40-inch (~1,016 mm) mounting span, the spring configuration distributes vertical roadway shock across a broader section of the trailer chassis. The wide 70 mm leaf footprint combined with the 10 mm blade gauge delivers outstanding torsional and lateral rigidity, effectively controlling trailer sway, chassis lean, and dynamic load shifting when carrying top-heavy machinery, liquid bowsers, or bulk agricultural cargo. Formed from premium oil-quenched and tempered high-tensile spring steel, it preserves its arch profile and elastic temper under punishing, high-mileage commercial duty cycles.

Key Features & Benefits:

• Heavy-Gauge 70x10mm Leaf Profile: Formed with extra-wide 70 mm leaves and 10 mm individual blade thickness to resist severe bending forces, blade splaying, and bottoming-out under heavy payloads.

• 7-Blade Progressive Multi-Leaf Stack: Multi-layer graduated architecture absorbs roadway shock and cyclic impacts, protecting chassis crossmembers, welds, and heavy axle beams from structural stress fatigue.

• Extended 40-Inch Span (~1,016 mm): The lengthened arc provides deeper, more progressive vertical deflection compared to shorter leaf packs, ensuring controlled ride compliance and reduced bounce when towing.

• High Torsional & Roll Stability: The wide 70 mm leaf footprint maximizes lateral stability to minimize trailer body roll, dynamic swaying, and shifting in high-center-of-gravity loads.

• Quenched & Tempered Spring Alloy Steel: Built from automotive-grade heat-treated spring steel to combat fatigue failure, leaf sagging, and loss of arch height over long working lifetimes.

• Standard Eye-to-Slipper Orientation: Forward rolled and bushed spring eye anchors securely into the front chassis hanger bracket for positive axle tracking, while the rear slipper tail glides freely to allow unrestricted longitudinal travel under compression.

• Commercial-Grade Toughness: Engineered to endure high cyclic stresses, heavy brake torque, and prolonged transit over corrugated, gravel, and industrial terrain.

Ideal Applications:

• Commercial & Plant Trailers: Suspension for tandem- and triple-axle plant trailers, machinery carriers, equipment transporters, and commercial flatbeds.

• Agricultural Implements & Farm Wagons: Heavy-duty running gear for grain carts, liquid fertilizer bowsers, feed wagons, and mobile field equipment.

• Mining & Industrial Service Trailers: Extreme-duty suspension for site diesel bowsers, lighting plants, tool trailers, and mobile compressor skids operating in quarry and industrial environments.

• Livestock Transporters & Horseboxes: Running gear engineered to handle dynamic animal movement while reducing body roll and trailer sway.

• Heavy Caravans & Overland Trailers: High-payload suspension builds designed for demanding, off-grid expedition setups.

Product Specifications:

• Product Name: 7 Blade Spring 40" (70x10)

• Product Category: Suspension / Leaf Springs

• Spring Type: Heavy-Duty Semi-Elliptical Leaf Spring (Eye-and-Slipper Design)

• Number of Blades: 7 Blades

• Spring Length (Mounting Span): 40 Inches (~1,016 mm)

• Blade Dimensions: 70 mm Width x 10 mm Blade Thickness

• Installation Orientation: Front Spring Eye mounts towards the front of the trailer

• Material: Quenched & Tempered High-Tensile Automotive Spring Steel

• Application Compatibility: Commercial Trailers, Caravans, Plant Equipment, Agricultural Machinery

• Condition: Brand New Heavy-Duty Commercial Vehicle Hardware