Continental Trading Corp. supplies secondary oil tempered steel wire (OT wire) sourced from North American producers at wholesale prices. Oil tempering is a heat treatment process in which high-carbon steel wire is heated above its critical transformation temperature, then rapidly quenched in oil to lock in a hardened martensitic structure, and finally tempered at a lower temperature to reduce brittleness. The result is wire with exceptional tensile strength, hardness, and fatigue resistance.
Our secondary oil tempered wire is material that fell outside a specific customer order — commonly tensile variation, surface cosmetics, or overproduction. The heat treatment process is complete and the wire exhibits its characteristic mechanical properties. For spring manufacturers and automotive suppliers, this represents a high-value opportunity.
Oil Tempered Steel Wire — Properties & Specifications
| Property | Specification |
|---|---|
| Carbon Grade | High carbon C1060–C1090 |
| Tensile Strength | 1,600–2,100 MPa (varies by diameter) |
| Diameter Range | 1.0mm – 16.0mm |
| Process | Oil quenched and tempered (martensitic microstructure) |
| Standards | ASTM A229 (general OT) / ASTM A401 (chrome-silicon OT) |
| Supply Form | Coils or spools |
| Quality | Secondary / Second choice (non-prime) |
Who Buys Surplus Oil Tempered Steel Wire?
Oil tempered (OT) wire buyers are primarily spring manufacturers serving automotive, furniture, and industrial markets. Automotive spring manufacturers — producing suspension springs, valve springs, and seat springs — are the highest-volume buyers of oil tempered wire. The automotive supply chain is extremely quality-conscious, and automotive-grade OT wire typically requires prime certification. However, non-automotive spring applications — furniture seats, box springs, industrial machinery, and garage door springs — often have more flexible incoming specifications and are well-suited to second choice OT wire.
Garage door spring manufacturers are consistent buyers of second choice OT wire. Garage door springs are large-diameter torsion or extension springs that must cycle thousands of times over the product's life. The fatigue properties of oil tempered wire — superior to hard-drawn wire — are required, but the exact prime certification is not. Second choice OT wire from a major North American producer delivers these fatigue properties at lower cost.
Industrial machinery manufacturers producing compression springs, die springs, and heavy-duty industrial springs purchase OT wire in diameters from 3mm to 16mm. Export buyers in Asia — spring manufacturers in China, India, and Taiwan — are consistent importers of North American surplus OT wire. Contact us with your diameter range, tensile grade, and quantity requirements.
Sourcing & Availability
Oil tempered wire is produced by drawing high carbon wire to the required diameter, then passing it through a lead or oil bath at elevated temperature to austenitize the steel, followed by rapid quenching in oil to produce a martensitic structure, then tempering at lower temperature to reduce brittleness. This complex heat treatment process is carried out at specialized facilities. Second choice OT wire arises when tensile values fall at the edge of the specified range, when surface condition is slightly outside specification, or when a production run exceeds the ordered quantity.
Continental Trading Corp. sources OT wire from North American wire facilities producing for automotive and non-automotive spring markets. We source standard oil tempered wire (ASTM A229 equivalent) and occasionally chrome-silicon OT wire (ASTM A401 equivalent) for high-performance spring applications. Diameter range is 1mm to 16mm. Availability is periodic — OT wire is not produced in the same volumes as commodity wire.
OT wire is in consistent demand from spring manufacturers worldwide. When available, lots move quickly. Register your diameter and tensile requirements with Continental Trading Corp. to be notified promptly when matching material is available.
Oil Tempered vs. Hard Drawn Spring Wire
Oil tempered wire and hard drawn spring wire are both used for spring manufacturing, but OT wire offers better consistency and higher fatigue life. The oil quenching process provides more uniform properties throughout the wire cross-section. This makes OT wire the preferred choice for precision springs in automotive suspensions, seating, and industrial machinery where reliable performance under cyclic loading is critical.
Specifications & Applications
Oil tempered wire is typically high carbon (C1060–C1090), with tensile strengths ranging 1,600–2,100 MPa depending on diameter. Common standards include ASTM A229 (general-purpose OT wire) and ASTM A401 (chrome-silicon OT wire for valve springs). Diameters typically range from 1.0mm to 16mm. Primary applications include automotive suspension springs, valve springs, seat springs, industrial coil springs, and garage door counterbalance springs. Contact us with your spec.
