| Parameter Item | Nominal Value | Tolerance | Unit |
| Wire Diameter | 14.8 | ±0.15 | mm |
| Outer Diameter | 122.0 | ±1.5 | mm |
| Inner Diameter | 92.4 | ±1.5 | mm |
| Free Length | 365.0 | ±3.0 | mm |
| Total Coils | 6.8 | ±0.25 | Coils |
| Active Coils | 5.5 | ±0.25 | Coils |
| Direction | Right-hand | — | / |
| End Type | Closed & Ground Flat | — | / |
| Spring Rate | 520 | ±4.0% | N/mm |
| Hardness | 48–50 | ±2 | HRC |
OEM Part Number:55350-3K010
Alternate OE: 553503K010 / 55350-3K011 (Replacement)
Product Name: Rear Suspension Coil Compression Spring
Application: Hyundai Sonata / Kia Optima (2008–2014)
Position: Rear Axle, Left & Right Universal
Weight: 3.10 kg (6.83 lbs)
Material: 60Si2Mn / SUP9 High Strength Spring Steel
Quality Standard: ISO/TS16949, JIS G 4801
Recommended Replacement: Replace in pairs (LH+RH)
Warranty: 2 Years / 100,000 km
