Dingtai manufactures Hitachi spring coils, heavy-duty recoil springs that maintain track tension and absorb shock loads in hydraulic excavator undercarriage systems.
We are a factory-direct supplier providing full OEM manufacturing and replacement production for US distributors, dealers, and equipment fleets.
Our spring coils resist fatigue, deformation, and cracking, preventing track derailment and reducing costly downtime in severe digging conditions.
With 20+ years of engineering experience and ISO9001/SGS certified processes, Dingtai delivers repeatable metallurgical quality and dimensional accuracy.
High-grade spring steel, precision coiling, controlled quenching, and shot peening ensure high fatigue strength and long service life under cyclic loading.
Core Selling Points
- 20+ Years Experience: Two decades manufacturing undercarriage components ensure proven engineering, material selection, and reliable batch consistency for critical excavator parts.
- Global Brand Compatibility: Spring coils are produced to Hitachi OEM specifications for direct fit, correct spring rate, and safe installation across popular excavator series.
- Deep Quenching/Heat Treatment: Controlled heating, quenching, and tempering improve fatigue resistance and prevent permanent set under cyclic heavy loads.
- 100% QC Inspection: Every batch undergoes dimensional checks, hardness testing, and surface inspection before shipment, reducing field failure risk.
Our catalog of Hitachi Spring Coil includes various specifications, fully compatible with Hitachi EX/ZX series excavators.
Why Choose Dingtai?
Production Technical Parameters
| Parameter | Specification |
|---|---|
| Material | 60Si2Mn / 55CrSi high-grade spring steel |
| Hardness (HRC) | 42–50 HRC after heat treatment |
| Process | Hot coiling, controlled quenching, tempering, shot peening |
| Certification | ISO9001 / SGS |
| Warranty | 12 months or 2,000 working hours |
OEM & Customization
We match OEM drawings, custom wire diameters, coil dimensions, and spring rates. Production strictly follows Hitachi undercarriage tolerance standards for reliable replacement.
Applicable Models
| Machine Type | Compatible Brands | Popular Series/Models |
|---|---|---|
| Hydraulic Excavator | Hitachi | EX200, EX300, ZX200, ZX330, ZX350, ZX470 |
| Large Excavator | Hitachi | ZX450, ZX650, ZX870 |
Delivery & Logistics
Factory-direct pricing with flexible MOQ. We ship by air, sea, or express to US ports and global destinations, with reinforced export packaging.
Technical Features
Hitachi spring coils operate as recoil springs within the track adjuster assembly, absorbing impact energy and maintaining constant track tension to protect idlers and frames.
Controlled quenching and tempering refine the steel grain structure, while shot peening introduces compressive surface stress that delays fatigue crack initiation.
Precision coiling ensures a consistent spring rate, which is essential for stable excavator track performance on rocky, sloped, or uneven terrain.
Applications
- Mining
- Road Construction
- Quarrying
- Demolition
- Heavy Civil Construction
Frequently Asked Questions
Q: What is the MOQ for Hitachi spring coils?
A: Stock replacement coils typically have an MOQ of 2–5 pieces. Custom OEM production may require 10–20 pieces.
Q: What is the delivery time to the United States?
A: Stock samples ship within 7–15 days. Bulk orders generally need 25–45 days production plus sea freight.
Q: How do you control heat treatment quality?
A: We use controlled quenching and tempering, then verify surface and core hardness on every batch to ensure uniform mechanical properties.
Q: Can you match Hitachi OEM part numbers?
A: Yes. Provide the Hitachi part number or drawing, and we will cross-reference and produce exact dimensional and spring rate matches.
Q: What is your warranty policy?
A: We offer a 12-month or 2,000-working-hour warranty against manufacturing defects, whichever occurs first.
Maintenance Guide
- Inspect spring coils every 1,000 hours for corrosion, cracks, or permanent set. Replace units below OEM free length limits.
- Clean the mounting area and check track adjuster components before installation. Align the coil correctly and avoid direct hammering.
- Grease tension cylinder and track frame contact points to ensure smooth recoil movement and even load distribution.
- Replace coils in matched pairs or complete undercarriage sets to maintain balanced track tension and prevent uneven wear.