A leaf spring is the most widely used elastic element in automobile suspensions.
It is an approximate equal strength steel beam composed of several alloy spring sheets of equal width and unequal length. Its main function is to transmit all forces and moments between wheels and frames, relax impactive load caused by the road surface and realize vehicle guidance, make vehicles normal drive.
Leaf springs are widely applied to suspensions for heavy duty trucks, light duty trucks, pick-ups, cars, skeletal trailers, lowbed trailers, flatbed trailers, oil tank trailers, van trailers, wood transport trailers, gooseneck trailers, agricultrucal vehicles, etc. Classification of Leaf Springs include Conventional leaf springs, parabolic leaf springs, Z type air linkers, TRA leaf springs, trailer leaf springs,light duyt trailer spring, boat trailer springs, pickup leaf springs, semi trailer springs, truck springs, farming/agricultural trailer springs, sprung drawbar, bus springs, bogie/boogie springs, heavy truck springs, etc.
For more about WONDEE Leaf Springs Project, please click：
|QC management system||Implementing IATF 16949-2016|
|Services quality management system||Implementing ISO 9001-2015|
|Product technical standards||Implementing GB/T 19844-2018, GT/T 1222-2007|
|Warranty||12 months since shipping date|
|Quality testing by||Stiffness Testing Machine, Arc Height Sorting Machine, and Fatigue Testing Machine, etc.|
|Raw material||Top 3 steel mills in China|
|Flat bar cutting & center hole punching||By fully automatic CNC cutting & punching production line|
Center hole positioning tolerance: <±0.2 mm
Cutting length tolerance: <±2 mm
|Leaf spring eye rolling||Use automatic CNC leaf eye rolling machines, robot assistance, dedicated molds and toolings to guarantee below features:|
1) Perpendicularity tolerance <1% x leaf width
2) Parallelism tolerance< 1% x leaf width
3) Eye diameter tolerance<±0.5 mm
4) Width tolerance of leaf end: -0.5mm ~ 0 mm
|Leaf tapering/parabolic rolling||Use automatic CNC parabolic taper rolling machines, robot assistance, dedicated molds and toolings to guarantee below features:|
1) Taper thickness allowance: <±0.25mm
2) Width tolerance of leaf end: -0.5mm~0 mm
|Heat treatment lines||1) Heating line: |
The large-scale automatic CNC temperature control heating furnace not only ensures the heating time but also ensures that the temperature in the furnace reaches the design value (the temperature difference is within ±5 degrees), ensures that the leaf springs are heated evenly, and avoids excessively high or low temperatures, thereby ensuring the strength of the leaf springs and the service life limit meets the Crequirements.
2) Quenching & camber making line:
Use special CNC quenching equipment, mechanical oil, camber making machines and robot assistance to ensure that the quenching temperature, quenching time and cambers reach the design requirements.
3) Tempering line:
A dedicated CNC tempering production lines are used to ensure that the tempering temperature and the tempering time meet the design requirements.
So as to ensure the strength and service life of leaf springs.
|Camber tolearance (mm)||≤±6 (Exceed spring industry standard ±7)|
|Fatigue life (cycles)||>120,000+( Exceed spring industry standard 100,000 cycles)|
|Shot peening||Using special leaf spring shot blasting machines, the new and used steel shots are mixed for use. On the one hand, the new steel shots increase the deformation of the springs. On the other hand, the used steel shots have no edges and corners to avoid microcracks on the surface of the springs, thereby increasing the fatigue life.|
|Painting||Normal painting and E-coating are available.|
*E-coating finish line: paint film is uniform and plump, with strong adhesion and high anti-corrosion performance, to avoid dripping, flow marks, stagnation marks and other problems.
* Salt spray test >100 hours
* Clients' logo are supported
* Design marks or stickers for clients, free of charge
|Other inspection equipment||*Metallographic Microscope,|
*Carbon & Sulfur Combined Analyzer, and
*Hardness Tester, etc.
|Oversea sales volume (tons)||14,000+|
|Overseas market||30+ countries ( German, France, Poland, Portugal, Russia, Filand, USA, Canada, Mexico, Thailand, Vietnam, Malaysia, Singapore, The Philippines, Indonesia, Brazil, Bolivia, Argentina, Ecualor, Chile, Peru, Guatemala, Panama, Egypt, South Africa, Nigeria, Tanzania, etc)|
|Land area (square meters)||30,000+|
|Tons of annual output||35,000+|
|Number of equipments (sets)||200+|
|Number of employees||260+|
|Number of engineers||10+|
|Available certificates||COC, PVOC, CIQ, SONCAP, BV, C/O, FORM E, FORM A.|
Comprehensive Info of Leaf Spring:
|Leaf spring types||Conventional leaf springs, parabolic leaf springs, Z type air linkers, TRA leaf springs, trailer leaf springs, boat trailer springs, pickup leaf springs, semi trailer springs, truck springs, farming/agricultural trailer springs, sprung drawbar, bus springs, bogie/boogie springs, heavy truck springs, light duty trailer springs/small springs, etc.|
|Materials grade:||SUP7, SUP9, SUP9A, SUP10, SUP11, SUP11A and SUP12|
60Si2Mn, 55CrMnA, 60CrMnBA, 50CrVA, 60CrMnBA, 60Si2CrA
61SiCr7, 55Cr3, 60CrB3, 51CrV4
9260, 5155, 5160, 6150, 51B60, 9254
|Spring width range (mm)||44.5~125 mm|
|Spring thickness (mm)||6~50 mm|
|Interchangeable brands (make)||MERCEDES BENZ, BPW, VOLVO, TOYOTA, HONDA, NISSAN, MAN, HOWO, SCANIA, RENAULT, DAF, MAN, ISUZU, IVECO, SISU, HYUNDA, TATRA, MAZ, SAF, ROR, FRUEHAUF, HINO, YORK, FUWA, CIMC, ETC.|
|Colors||Red, shinning black, dark black, grey, blue, as required.|
|Optional parts, components, & related parts||Centor bolts, clamps, |
Copper bushes, bi-metal bushes, steel rubber bushings, rubber bushes, nylon bushes.
U-bolts, brackets, pins.
|Package||Fumigated wooden pallets, steel pallets, as required.|
|Standards implemented||IATF 16949-2016, ISO 9001-2015, GB/T 19844-2018, GT/T 1222-2007|
|Payment terms||TT, LC, DP.|
|Lead time||About 25~35 working days.|
Some conventional leaf springs for heavy duty semi trailers:
|Item Number|| |
|Cut Length of 1st Leaf L (mm)||Free Camber H (mm)|| |
Note 1: Other leaf springs for heavy duty trailers are available;
Note 2: Other classification of leaf spring are available, include: conventional leaf springs, parabolic leaf springs, Z type air linkers, TRA leaf springs, trailer leaf springs, light duyt trailer spring, boat trailer springs, pickup leaf springs, semi trailer springs, truck springs, farming/agricultural trailer springs, sprung drawbar, bus springs, bogie/boogie springs, heavy truck springs, etc.
(Leaf Springs Quenching Line)
(Leaf Springs Automatic Rolling and End Treatment Lines)
Leaf springs quality testing (Spring Fatigue Life Testing, Spring Pre-press Testing, Spring Hardness Testing, Spring Rigidity Testing)
Production process of trailer leaf springs :
Spring steel flat bar→ 2. Spring cutting→ 3. Spring straightening→ 4. Spring hole drilling→ 5. Spring eye rolling→ 6. Spring quenching→ 7. Spring tempering→ 8. Spring assembling→ 9. Spring painting→ 10. Spring mark making.
The more about roduction process of leaf springs, please kindly visit YOUTUBE link:
( Leaf Springs Painting and Packing)