Changzhou ST. Key Machiney Co., Ltd
Best service ; excellent quality ; quick delivery time
At Changzhou ST. Key Machinery Co., Ltd, every industrial roller represents over 25 years of manufacturing expertise, advanced equipment, and rigorous quality control. With an 80%–90% export ratio and annual capacity exceeding 6,000 precision rollers, our factory combines traditional engineering mastery with cutting-edge technology to serve clients worldwide.
Unlike many suppliers who outsource critical processes, ST. Key maintains complete in-house control over every manufacturing stage:
| Stage | Process | Key Equipment & Technology |
|---|---|---|
| 1. Material Selection | Incoming inspection of 45#, 20#, 42CrMoA alloy steel billets and seamless pipes | Spectrometer analysis, ultrasonic flaw detection |
| 2. Forging & Welding | Integrated shaft forging and roller body welding with stress-relief treatment | Hydraulic forging press, submerged arc welding |
| 3. Heat Treatment | Quenching, tempering, and normalizing for optimal hardness and dimensional stability | Computer-controlled heat treatment furnaces |
| 4. Rough Machining | Turning to near-net dimensions with stock allowance for finishing | CNC heavy-duty lathes |
| 5. Precision Machining | Final turning and grinding to achieve ≤ 0.01mm TIR concentricity | CNC cylindrical grinders, precision lathes |
| 6. Surface Engineering | Chrome plating (0.03–0.12mm), plasma-sprayed ceramic coating, or rubber bonding | Electroplating line, plasma spray system, rubber vulcanization |
| 7. Engraving & Texturing | Pattern creation via laser, CNC cutter, or chemical corrosion | ALE fiber laser engraver, 5-axis CNC router |
| 8. Final Finishing | Mirror polishing, sand finishing, or matte treatment per specification | Super-finishing machines, surface roughness testers |
| 9. Quality Inspection | Full dimensional, concentricity, hardness, surface finish, and balance testing | CMM, hardness testers, dynamic balancers, profilometers |
| 10. Packaging | Protective wrapping and custom wooden crates for export | Standard export packing line |
ST. Key Machinery operates under a 5S lean management system with continuous improvement programs. Our quality assurance framework includes:
Our commitment to manufacturing excellence is supported by ongoing investment in:
With a workforce of 100–150 skilled professionals, 25+ years of specialized experience, and a track record of serving clients across Europe, the Americas, Southeast Asia, and the Middle East, ST. Key Machinery is your reliable partner for industrial roller solutions. Contact us today to discuss your requirements or schedule a factory visit.
Contact Person: Mr. Yun
Tel: +8613951236008
Fax: 86-0519-86315782