Six integrated processing services — slitting, cut-to-length and leveling, spheroidizing annealing, heat treatment, precision cold rolling, and OEM/ODM custom — performed in-house in Shanghai with documented parameters and MTC on every coil.
Coils are slit to customer width on precision slitting lines. Circular shear knives cut the strip longitudinally, with knife clearance matched to material thickness to minimize burr. Width tolerance and burr height are verified at the line and again at final inspection. Narrow widths for progressive-die stamping and wide widths for blanking feeders are both handled.
| Parameter | Typical Range | Notes |
|---|---|---|
| Width tolerance | ±0.05 mm (narrow) / ±0.10 mm (wide) | Confirmed at RFQ per spec |
| Burr height | ≤ 5% of thickness (typ.) | Managed via knife clearance & overlap |
| Minimum slit width | Confirm at RFQ | Depends on thickness & material strength |
| Applicable thickness | 0.2 – 4.0 mm (typ.) | Thicker gauges by arrangement |
| Edge condition | Sheared edge, deburred on request | Rolled edge available for special orders |
Coils are leveled through a multi-roll leveling machine and sheared to fixed-length sheets. The leveling process removes coil set and crossbow, producing flat sheet suitable for laser cutting, blanking presses and sheet-fed stamping. Length tolerance and flatness are controlled by machine setup and verified per stack.
| Parameter | Typical Range | Notes |
|---|---|---|
| Length tolerance | ±0.5 mm / ±1.0 mm (per length) | Tighter tolerance on request |
| Flatness | ≤ 3 mm/m (typ.) | Measured per sheet or per stack |
| Diagonal tolerance | ≤ 1.0 mm (typ.) | Squareness check on every batch |
| Sheet length range | 500 – 3000 mm (typ.) | Longer lengths by arrangement |
| Applicable thickness | 0.3 – 4.0 mm (typ.) | Thicker gauges by arrangement |
Batch furnaces run a controlled heating and slow-cool cycle that converts lamellar pearlite into spheroidal carbide. The result is a soft, ductile strip that blanks cleanly and cold-forms without cracking — the standard condition for fine blanking and cold-forming grades. Hardness is controlled by cycle temperature and hold time, and verified on process samples from each batch.
| Parameter | Typical Range | Notes |
|---|---|---|
| Annealing temperature | 680 – 760 °C (typ.) | Grade-specific; confirmed per material |
| Hardness after annealing | 160 – 200 HB (high-carbon typ.) | Grade and section dependent |
| Spheroidization rate | ≥ 90% (typ.) | Verified by metallographic examination |
| Applicable steel types | High-carbon, medium-carbon, alloy spring steel | SAE1078, 65Mn, 51CrV4, C67S, etc. |
| Decarburization control | Limited per cycle; depth on request | Measured on process samples |
Quenching, tempering and normalizing lines deliver finished mechanical properties for spring, blade and structural applications. Quenching hardens the strip to target hardness; tempering relieves stress and tunes toughness; normalizing refines grain structure for improved uniformity. Hardness ranges are specified per grade and section, with results recorded on the MTC.
| Process | Hardness Range (typ.) | Typical Use |
|---|---|---|
| Quenching | 50 – 62 HRC (grade dependent) | Spring steel, tool steel, saw blade strip |
| Tempering | 38 – 52 HRC (after quench) | Spring temper, blade temper, toughness tuning |
| Normalizing | 150 – 220 HB (typ.) | Grain refinement, uniform mechanicals |
| Hardened & tempered (H&T) | 38 – 48 HRC (spring strip typ.) | Finished springs, clutch plates, blades |
Multi-pass cold rolling reduces strip thickness to target gauge with controlled surface roughness and crown. Rolling pass schedule is designed per grade and final thickness to achieve the required mechanical properties and surface finish. Thickness is measured continuously at the mill and verified at final inspection. This service is often combined with annealing to produce soft-annealed precision strip.
| Parameter | Typical Range | Notes |
|---|---|---|
| Thickness tolerance | ±0.01 – ±0.03 mm (typ.) | Tighter on request; gauge dependent |
| Surface roughness (Ra) | 0.2 – 1.6 μm (typ.) | Bright / matte / rolled finish options |
| Edge quality | Rolled edge, slit edge on request | Edge wave controlled per pass |
| Final thickness range | 0.1 – 3.0 mm (typ.) | From pickled or hot-rolled feed |
| Width range | Confirm at RFQ | Mill width capability per order |
For specifications outside standard stock — special widths, non-standard thicknesses, custom annealing cycles, branded packaging, or toll processing of customer-supplied material — our engineering team designs a custom process route. We work from your drawing or written specification, confirm feasibility with a trial coil where needed, and then run production under the same quality system as standard orders.
| Custom Option | Capability | Notes |
|---|---|---|
| Custom width / thickness | Non-standard slitting & rolling | Feasibility confirmed at RFQ |
| Custom annealing cycle | Grade-specific thermal cycles | Trial coil recommended for new specs |
| Special surface / edge | Bright, matte, polished, rounded edge | Per customer requirement |
| Custom packaging | Branded wrapping, palletization, labeling | Export packaging standard |
| Toll processing | Customer-supplied coil processing | Incoming inspection + processing fee |
Every order — stock or custom — follows the same controlled sequence from inquiry to dispatch.
Grade, spec, quantity and destination confirmed.
Engineering reviews feasibility and process route.
Trial coil for new or non-standard specs.
Processing per confirmed route and parameters.
Dimension, hardness, surface and chemistry checks.
Export packaging, MTC issuance and shipping.
These grade families share material, processing or application territory with the topic on this page.
SAE1078 / 65Mn / SK5 grades for hardened parts, springs and cutting edges.
DP / TRIP / HSLA grades (HC180YD, HC260LA, DP590) combining strength with formability for lightweighting.
301 / 304 / 316 grades with excellent corrosion resistance and formability for springs, medical and food parts.
Invar / Kovar / Elinvar / Nichrome precision alloys for electromagnetic, thermal-bimetal and resistance applications.
Tell us your grade, target condition and quantity. Our engineers will confirm the process route and quote within one working day.