1. Chemical Composition & Mechanical Properties of Leaf Spring Steels
Choosing the wrong leaf spring material for a given blade thickness causes incomplete core martensite transformation during oil quenching, leading to rapid arch sagging or brittle eye fracture. Below is our laboratory metallographic and mechanical comparison across JIS G 4801, SAE J404, DIN EN 10089, and GB/T 1222 standards:
| Steel Grade | Equivalent Standards | Carbon & Alloying Elements | Tensile / Yield Strength | Quenched & Tempered Hardness | Max Hardenable Thickness & Use Case |
|---|---|---|---|---|---|
| SUP9 | SAE 5155 / DIN 55Cr3 / 55CrMnA | 0.52–0.60% C, 0.65–0.95% Mn, 0.65–0.95% Cr | ≥1,225 MPa / ≥1,080 MPa | 388–461 HBW (41–48 HRC) | t ≤ 20 mm; TRA-2726, Mitsubishi MC413899/F |
| SUP9A | SAE 5160H / 60CrMnA | 0.56–0.64% C, 0.70–1.00% Mn, 0.70–1.00% Cr | ≥1,275 MPa / ≥1,125 MPa | 401–461 HBW (42–48 HRC) | t ≤ 28 mm; Heavy Truck Multi-Leaf Springs |
| SUP11A | SAE 51B60H / 60CrMnBA | 0.56–0.64% C, Cr-Mn + 0.0005–0.0035% Boron | ≥1,325 MPa / ≥1,175 MPa | 401–477 HBW (43–49 HRC) | t ≤ 45 mm; 24T Bogie Packs & Mining Trucks |
| 50CrVA | DIN 51CrV4 / SAE 6150 / SUP10 | 0.47–0.55% C, 0.80–1.10% Cr, 0.10–0.25% V | ≥1,375 MPa / ≥1,225 MPa | 415–477 HBW (44–50 HRC) | t ≤ 56 mm; BPW 880368, TRA-021 Mono-Leaf |
| 60Si2Mn | SAE 9260 / DIN 60SiCr7 / SUP7 | 0.56–0.64% C, 1.50–2.00% Si, 0.60–0.90% Mn | ≥1,274 MPa / ≥1,176 MPa | 375–444 HBW (40–46 HRC) | t ≤ 14 mm; 750lb–1750lb Utility Trailer Springs |
2. Heat Treatment, Decarburization Control & Load-Simulated Stress Shot-Peening
Even premium virgin SUP9A or 50CrVA spring steel will fail prematurely if surface carbon is lost during furnace heating. At XIANGZEWO’s IATF 16949:2016 plant, every batch is verified by metallographic microscope (total decarburization layer ≤0.20 mm), quenched in temperature-controlled polymer/oil baths, tempered in hot-air circulating furnaces, and stress shot-peened under rated load to guarantee ≥180,000 bench fatigue cycles.
Complete XIANGZEWO Leaf Spring Engineering Guides, Category Hubs & OEM Part Number Directory
Explore our direct IATF 16949:2016 factory technical guides, suspension architecture comparisons, and OEM replacement specification pages (2-hop direct engineering index):
1. Core Suspension Hubs & Custom Engineering Services
China Leaf Spring Manufacturer Home |
All Heavy-Duty Leaf Springs |
Commercial Truck Leaf Springs |
Utility & Semi-Trailer Leaf Springs |
Custom Leaf Springs by Drawing |
Parabolic Leaf Spring Services & Testing |
Parabolic Tapered Springs |
Multi-Leaf Springs |
Long Taper Springs |
Z-Leaf Air Suspension Springs |
Agricultural Leaf Springs |
OEM Catalog Shop |
About XIANGZEWO Factory |
Manufacturing FAQ |
Technical Blog |
Request a 24h OEM Quote
2. Truck & Trailer Brand Category Hubs
Isuzu Leaf Springs |
Scania Leaf Springs |
Mitsubishi Fuso & Canter Leaf Springs |
BPW Trailer & Bogie Leaf Springs |
Hutchens / American TRA Trailer Springs |
Semi-Trailer Bogie & Germany-Type Springs |
Air Link Trailing Arm Springs |
Air Beam Suspension Springs |
Ford Truck Leaf Springs |
Freightliner Leaf Springs |
International Navistar Leaf Springs |
Nissan UD Leaf Springs |
Toyota & Hino Leaf Springs |
Light-Duty & Export Truck Leaf Springs |
Volvo Truck Springs |
MAN Truck Springs |
Mercedes-Benz Truck Springs |
Hendrickson Suspension Springs |
Mack Truck Springs |
Iveco Truck Springs |
Kamaz Truck Springs |
GAZ Light Truck Springs |
Hyundai Truck Springs |
Volkswagen Commercial Springs |
Specialty OEM Leaf Springs
3. Direct OEM Part Number Specification Pages (30 Verified Models)
Trailer & Bogie Series:
Hutchens TRA-2726 (3L 76×20mm) |
Hutchens TRA-2727 Parabolic |
Hutchens TRA-2728 Low-Arch |
Hutchens TRA-2732 (8-Leaf) |
Hutchens TRA-2740 (3L 76×24mm) |
Reyco TRA-2260 (8-Leaf) |
Fruehauf TRA-699 (4-Leaf) |
Fruehauf TRA-021 Mono-Leaf (50CrVA) |
11436 Semi-Trailer Spring (9L 76×14mm) |
T410012 Germany-Type Trailer Spring (11L 100×12mm) |
BPW 24T Bogie Spring (18L 90×13/17mm) |
1.75" 4-Leaf Mobile Home & Utility Trailer Spring (750lb–1750lb) |
1.75" Tapered Mono-Leaf RV & Boat Trailer Spring |
80×20×1600mm 12-Leaf Heavy Trailer Pack
Commercial Truck & Air Suspension Series:
Isuzu 1-51130-961-0 Parabolic/Multi-Leaf |
Scania 1421060 Air Suspension Spring (100×47/45mm) |
BPW 880368 Air Link Spring (100×38mm 51CrV4) |
Forged Z-Type Air Beam Trailing Arm |
Mitsubishi MC413899/F, L200 MR448146 & Canter MB294519 |
Nissan UD 54010-Z3007-FA Parabolic (90×12mm 9L) |
Ford 43-698 Front Truck Pack (9L 100mm) |
Ford 43-1199 (431199) Truck Pack (4L 63mm) |
Freightliner 46-1189 Class 8 Pack (13L 76mm) |
International 55-031 Navistar Pack (13L 76mm) |
HPF5 Light Truck Spring (6L 70×11/13mm) |
IE2F P60/10/6V Light Commercial Spring |
TC P60/8/2 Light-Duty 3+2 Leaf Spring |
NDT P60/8/2 Front Parabolic Light Truck Spring |
3" Variable-Section Heavy Truck Parabolic Spring |
6–56mm Custom OEM Truck & Bus Leaf Springs (MAN/Volvo/Hino/YUTONG)
4. Technical Calculators, Load Charts & Industry Guides
Types of Leaf Springs: Cantilever, Semi-Elliptical & Full Elliptical Guide |
Interactive Leaf Spring Rate & Load Capacity Calculator |
110+ OEM Truck & Trailer Leaf Spring Cross-Reference Chart |
Parabolic Leaf Spring Services vs. Semi-Elliptic Multi-Leaf Guide |
3-Leaf to 6-Leaf Trailer Leaf Spring Load Chart (705lb–5000lb) |
Custom Truck Leaf Springs |
Agricultural Trailer Leaf Springs |
Automotive Aftermarket Leaf Springs |
Oilfield & Frac Trailer Leaf Springs |
Mining Dump Truck Leaf Springs |
Military-Wrap Tactical Leaf Springs |
Construction Mixer & Lowboy Leaf Springs |
Engineering Guides Archive |
Custom Industry Archive
Additional OEM Suspension Configurations: For specialized heavy-duty axle and air-suspension applications, compare our 24T Heavy-Duty Bogie Multi-Leaf Suspension Spring Pack, Custom OEM Heavy Truck SUP9/50CrVA Leaf Spring Assembly engineered with shot-peened SUP9A and 50CrVA alloy steel.
Frequently Asked Engineering & OEM Procurement Questions (FAQ)
What material is best for heavy-duty truck and trailer leaf springs?
SUP9 (SAE 5155) and SUP9A (SAE 5160H) are the industry standard for multi-leaf truck and trailer springs up to 28 mm thick. For thick parabolic springs and Z-type air suspension arms (28 mm to 56 mm thick), 50CrVA (DIN 51CrV4) and SUP11A boron-alloy steel provide superior core hardenability and fatigue life.
