Dingtai manufactures Sumitomo spring coils that maintain constant track tension and absorb high-impact loads in excavator undercarriage systems.
We are a factory-direct supplier offering complete OEM manufacturing services for global distributors and equipment owners.
Our spring coils resist fatigue deformation and cracking, preventing track derailment and reducing costly downtime on site.
With over 20 years of experience and ISO9001/SGS certification, Dingtai provides batch-consistent quality for demanding applications.
We use high-grade 60Si2Mn spring steel, controlled deep quenching, and shot peening to ensure long service life.
Core Selling Points
- Premium Spring Steel: Manufactured from high-grade 60Si2Mn spring steel, our coils deliver high tensile strength and excellent fatigue resistance under repeated shock loads.
- Deep Quenching/Heat Treatment: Controlled quenching and tempering produce uniform hardness, reducing permanent set and maintaining reliable track tension over time.
- Global Brand Compatibility: Engineered as direct replacements for Sumitomo excavator models, matching OEM dimensions for straightforward installation and correct fit.
- 100% QC Inspection: Each coil undergoes dimensional checks, hardness testing, and visual inspection before shipment to ensure zero-defect delivery.
Product Series Overview
Our catalog of Sumitomo Spring Coil includes various specifications, fully compatible with Sumitomo excavators and bulldozers.
Why Choose Dingtai?
Production Technical Parameters
| Parameter | Specification |
|---|---|
| Material | 60Si2Mn / 55CrSi spring steel |
| Hardness | HRC 42–48 after quenching and tempering |
| Manufacturing Process | Hot coil winding, quenching, tempering, shot peening, anti-corrosion coating |
| Quality Certification | ISO9001:2015, SGS material report |
| Warranty | 12 months or 2,000 working hours |
OEM & Customization
We produce spring coils from customer drawings or samples, matching original dimensions, load ratings, and coating requirements to strict OEM standards.
Applicable Models
| Machine Type | Compatible Brands | Popular Series/Models |
|---|---|---|
| Hydraulic Excavator | Sumitomo | SH120, SH200, SH210, SH240, SH300, SH350, SH480 |
| Material Handler | Sumitomo | SH210, SH240, SH300 |
Delivery & Logistics
We offer factory-direct pricing, flexible MOQ, and reliable export packing for global delivery, including FOB, CIF, and DDP options.
Technical Features
The coil spring is manufactured from high-silicon spring steel, providing excellent elastic recovery and resistance to permanent set under repeated compression.
Shot peening introduces compressive residual stress on the surface, reducing crack initiation and extending fatigue life in high-cycle undercarriage applications.
Precision hot winding and controlled tempering ensure consistent spring rate and free length, maintaining correct track tension throughout service.
Applications
- Mining operations with abrasive rock and continuous track impact loads.
- Road construction sites requiring tracked excavators for grading and trenching.
- Quarrying applications with high-frequency undercarriage stress.
- Demolition and heavy material handling operations.
Frequently Asked Questions
What is the minimum order quantity for Sumitomo spring coils?
Our standard MOQ is 10 pieces per specification. Smaller trial quantities may be accepted based on stock availability.
What is the delivery time?
Standard delivery is 15–25 days after order confirmation. Custom OEM production may require 30–45 days depending on quantity and process.
Can you match my original part number?
Yes. Provide your Sumitomo part number or drawing, and we will confirm compatibility with our engineering team before production.
What material and heat treatment do you use?
We use 60Si2Mn or 55CrSi spring steel, quenched and tempered to HRC 42–48, then shot-peened for fatigue resistance.
How does heat treatment depth affect spring life?
Controlled through-hardening prevents soft spots and inconsistent hardness across the cross-section, reducing premature sagging and breakage.
What warranty do you provide?
We provide a 12-month or 2,000-hour warranty against manufacturing defects under normal operating conditions.
Do you supply OEM or customer-branded packaging?
Yes, we offer OEM services with neutral or custom branding, including labels, boxes, and laser marking.
Maintenance Guide
- Inspect spring coils for cracks, corrosion, or uneven coil spacing during routine undercarriage maintenance.
- Check track tension regularly; insufficient tension may indicate spring fatigue or loss of free length.
- Replace both track adjuster springs on the same side if one fails to maintain balanced track frame loading.
- Always relieve track tension before removing the spring assembly to prevent injury.
- Apply anti-corrosion coating after installation and re-torque mounting bolts after 50 working hours.