Main Leaf: Load Capacity 1000-5000 kg, Eye Diameter 25-50 mm

Component Specifications

Definition

The main leaf is the longest and thickest leaf in a multi-leaf spring assembly, serving as the primary structural member that carries the majority of the load and provides the foundational spring action. It typically features eyes or hooks at both ends for attachment to the vehicle frame and axle, and acts as the master leaf that guides the alignment and movement of the entire spring pack.

Working Principle

Works on the principle of beam bending under load, where the main leaf's curvature changes to absorb and store energy from road irregularities, then releases it to maintain vehicle stability and ride comfort. It distributes vertical forces through its length while maintaining lateral and longitudinal alignment.

Materials

Typically made from high-carbon spring steel (SAE 5160, 6150, or 9260) or micro-alloyed steels, heat-treated to achieve Rockwell hardness of 45-50 HRC, with yield strength of 1200-1500 MPa and tensile strength of 1400-1800 MPa.

Technical Parameters

Parameter	Typical range	Notes & selection driver
Width	50-100 mm
Camber	50-200 mm
Length	500-2500 mm
Thickness	8-20 mm
Eye Diameter	25-50 mm
Load Capacity	1000-5000 kg

Ranges are indicative industry figures for RFQ preparation, not a supplier commitment. Confirm every value and standard with the legal manufacturer before ordering.

Standards

ISO 18137, DIN 2093, SAE J510

Parent Products

This component is used in the following industrial products

Spring System (Leaf Springs)

A leaf spring assembly that provides controlled vibration and support in vibratory feeding systems.

View Product Details

Engineering Analysis

Risks & Mitigation

Fatigue failure due to cyclic loading
Corrosion in harsh environments
Eye bushing wear leading to alignment issues
Center bolt shear failure

FMEA Triads

Trigger: Overloading beyond rated capacity
Failure: Permanent set or sagging
Mitigation: Implement load monitoring systems and adhere to manufacturer weight limits

Trigger: Inadequate lubrication at friction points
Failure: Premature wear and squeaking
Mitigation: Regular maintenance with appropriate anti-friction coatings

Trigger: Stress concentration at eye ends
Failure: Crack initiation and propagation
Mitigation: Design with proper radius transitions and shot peening treatment

Industrial Ecosystem

Compatible With

Typical Suppliers & Equivalents

Compliance & Inspection

Tolerance

±1.5 mm on length, ±0.5 mm on thickness, ±0.3° on eye alignment

Test Method

Fatigue testing per ISO 18137 (minimum 100,000 cycles at 150% design load), static load testing, salt spray corrosion testing per ASTM B117

Procurement Evaluation Criteria

A practical evidence checklist for RFQ preparation and supplier evaluation.

Technical documentation

Request current drawings, revision history, and a signed specification sheet.

Manufacturing capability

Verify equipment lists, process limits, capacity, and representative production evidence.

Inspection readiness

Confirm test methods, calibrated equipment, sampling plans, and traceable reports.

Supplier transparency

Check the legal entity, factory address, ownership, certifications, and direct contacts.

CNFX does not score or rank suppliers. Buyers must verify all claims and documents with the legal manufacturer before ordering.

Manufacturers of Main Leaf

Manufacturer profiles associated with Main Leaf.

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Compiled and source-reviewed by the CNFX editorial team. Each manufacturer above links to the page on that company's own website where the product is listed, with the date we checked it. How we source and review

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Frequently Asked Questions

What is the difference between main leaf and helper leaves in a leaf spring?

The main leaf is the longest, thickest leaf that carries the primary load and provides structural attachment points, while helper leaves (secondary leaves) are shorter, progressively thinner leaves that add load capacity and damping characteristics to the spring system.

How often should main leaf springs be inspected?

Main leaf springs should be visually inspected every 25,000 km or 6 months for cracks, sagging, or wear at attachment points, with detailed inspection during regular vehicle maintenance intervals as specified by the manufacturer.

Data Basis

Editorial classification, named public sources where available, and source-reviewed manufacturer records. See the editorial policy.

Preliminary Technical Classification

This page supports structured research, RFQ preparation, and supplier evaluation. It does not replace buyer-led supplier qualification, standards review, or technical approval.

Main Leaf