From Raw Material to Finished Product: Our Quality Control System

At GreaThermos, the manufacturing arm of Jinhua Great Metal Products Co., Ltd., quality is not an afterthought—it is built into every stage of production. With more than 10 years of experience in stainless steel drinkware, we have developed a rigorous quality management system that ensures every bottle, mug, and flask leaving our factory meets the highest international standards.

1. Raw Material Inspection

Every production run begins with strict verification of incoming stainless steel and food-contact materials. We only work with certified suppliers who provide documented material traceability. Our incoming quality control team checks for grade authenticity, surface condition, thickness, and chemical composition. Only materials that pass our screening are released to the workshop.

2. In-Process Quality Checks

Throughout manufacturing—from cutting, forming, welding, and polishing to assembly—our floor inspectors conduct regular patrol inspections and first-article reviews. Key parameters such as dimensional accuracy, weld integrity, surface finish, and vacuum performance are monitored in real time. This allows us to detect and correct any deviation before it becomes a defect.

3. Finished Product Testing

After assembly, every batch of finished drinkware undergoes a series of functional and safety tests. These include leakage tests, vacuum insulation performance checks, thermal shock resistance, and durability assessments. We also evaluate lid sealing, thread compatibility, and overall workmanship to ensure a premium user experience.

4. Food-Safety and Material Certification

Because our products are designed for daily drinking use, we prioritize food safety. All materials used are certified to meet FDA, LFGB, and Proposition 65 (Pro65) requirements. These internationally recognized certifications validate that our drinkware is free of harmful substances like BPA, lead, and other restricted chemicals. We conduct regular third-party testing to maintain compliance.

5. Final Audit and Packaging

Before shipment, our quality assurance team performs a final random inspection based on international sampling standards. Visual appearance, print/logo accuracy, and packaging integrity are reviewed. We also use biodegradable packaging materials, reflecting our commitment to sustainability from product to package.

6. Continuous Improvement and OEM Support

Our quality system is constantly updated to meet new regulations and customer expectations. For OEM and wholesale orders, we provide open communication at every step—from material selection to pre-shipment inspections—ensuring your private-label drinkware is produced with consistent quality and reliability.

When you partner with Jinhua Great Metal Products Co., Ltd., you are choosing a factory that treats quality control as a shared responsibility. From the first piece of stainless steel to the last packaged box, we are committed to delivering safe, durable, and sustainable drinkware you can trust.