Oil Quenched and Tempered Spring Steel Wire is a high-performance steel wire processed through controlled heating, rapid oil quenching, and precise tempering. This treatment creates a uniform martensitic microstructure that delivers excellent tensile strength, fatigue resistance, and spring performance under repeated load. It is widely used in automotive suspension springs, valve springs, clutch springs, and heavy-duty industrial springs where long service life and dimensional stability are mandatory. Luguan produces this wire with tightly controlled chemical composition, precise diameter tolerance, and consistent mechanical properties to meet demanding manufacturing environments.
The production process at Luguan follows strict steps to ensure repeatability and consistency. The main stages include:
Luguan offers a wide range of sizes, grades, and surface conditions to match different spring manufacturing requirements. The tables below summarize the standard specifications. Custom sizes and properties are available upon request.
| Parameter | Standard Range | Custom Range |
|---|---|---|
| Wire diameter | 1.5 mm – 20.0 mm | 0.8 mm – 25.0 mm |
| Diameter tolerance | ±0.02 mm (for ≤10 mm) | ±0.01 mm available |
| Diameter tolerance | ±0.03 mm (for >10 mm) | ±0.02 mm available |
| Coil weight | 100 kg – 2000 kg | Custom coil weight |
| Coil inner diameter | 400 mm – 1200 mm | Custom ID available |
Luguan oil quenched and tempered spring steel wires provide several measurable performance advantages. These characteristics are verified through destructive and non-destructive testing on every production lot.
The combination of high strength, toughness, and fatigue resistance makes this wire suitable for a broad range of spring types and demanding environments.
Luguan has built a strong reputation in the spring steel wire industry through consistent quality, technical support, and reliable delivery. The company uses carefully selected steel billets from certified mills and maintains full traceability from raw material to finished coil. In-house drawing, heat treatment, and testing capabilities give Luguan direct control over every production step, reducing lead times and improving responsiveness to customer requirements.
Luguan also provides technical guidance on grade selection, heat treatment adjustments, and surface coating options. The sales and engineering teams work closely with spring manufacturers to solve production issues related to coiling, stress relief, shot peening, or fatigue performance. This level of support helps customers reduce scrap, improve spring performance, and bring products to market faster.
What is the difference between oil quenched and tempered wire and cold drawn spring wire?
Cold drawn spring wire is hardened primarily by cold working during drawing. Oil quenched and tempered spring steel wire is hardened by heat treatment after drawing. The oil quenched and tempered process creates a more uniform microstructure with higher fatigue resistance and better performance at larger diameters. Cold drawn wire typically has higher tensile strength at small diameters but may lack the same level of toughness and thermal stability as quenched and tempered wire. For spring applications requiring long fatigue life, high load capacity, or operation at elevated temperatures, oil quenched and tempered wire is usually the better choice.
What steel grades are available?
Luguan produces oil quenched and tempered spring steel wires in several standard grades, including SAE 9254, SAE 6150, SAE 5160, DIN 55SiCr7, and DIN 50CrV4. Other grades such as SAE 9260, SUP9, SUP10, and 60Si2Mn are also available upon request. The choice of grade depends on the required tensile strength, operating temperature, corrosion resistance, and spring design. For example, chromium-vanadium grades like 50CrV4 offer better toughness and fatigue resistance at high stress levels, while silicon-chromium grades like 55SiCr7 provide excellent relaxation resistance at elevated temperatures.
How does the tempering temperature affect the final properties of the wire?
Tempering temperature directly controls the balance between strength and ductility. Lower tempering temperatures produce higher tensile strength and hardness but reduce toughness and ductility. Higher tempering temperatures lower the tensile strength but improve ductility, toughness, and resistance to impact loading. Luguan adjusts tempering temperature according to customer specifications and spring design requirements. For most automotive suspension springs, tempering temperatures between 400°C and 480°C provide an optimal combination of high fatigue strength and sufficient toughness. The exact temperature is selected based on the steel grade, wire diameter, and desired mechanical property window.
How does Luguan ensure consistent mechanical properties along the entire coil length?
Luguan uses continuous furnace lines with precise temperature control and constant line speed to ensure uniform heating, quenching, and tempering along the whole coil. Multiple temperature sensors monitor the furnace zones, and the quenching oil bath is equipped with circulation and cooling systems to maintain stable oil temperature. After heat treatment, samples are taken from both ends and the middle of each coil for tensile and hardness testing. This sampling plan verifies that mechanical properties remain within specification from start to finish, reducing the risk of property variation that could cause spring failure or inconsistent coiling behavior.
To request a quotation or discuss your specific spring wire requirements, contact Luguan with the following information: steel grade, wire diameter, required tensile strength range, surface coating preference, coil weight, and estimated annual volume. Luguan technical engineers will recommend the most suitable grade and processing route based on your spring design and production equipment. Material test certificates, inspection reports, and sample coils are available for customer evaluation before bulk order placement.
