Quality Assurance
Our 100% in-house facilities makes us independent and self-reliant for assurance of quality parts and development.
Quality is not an added feature—it is built into our system. Our manufacturing and quality management processes operate in accordance with IATF 16949, ensuring strict control over product consistency, traceability, and continuous improvement across all production stages.
In addition, our products comply with international material and environmental regulations, including RoHS, SVHC, and REACH, meeting the requirements of global OEMs and aftermarket customers.





Quality control begins with raw material verification and continues through every manufacturing step. Chemical composition analysis, dimensional control, heat treatment verification, and surface quality inspection are integrated into our daily production routines.
This process-driven approach allows us to maintain stable quality not only in small batches, but also in high-volume production.
To ensure reliability in real engine operation, all engine valves and valve tappets undergo 100% final inspection. Critical parameters such as dimensions, surface integrity, sealing performance, and functional characteristics are thoroughly checked before shipment.
This inspection philosophy minimizes risk for customers and ensures that every delivered part meets defined technical requirements.
Quality control begins at the blank inspection stage. All blanks are inspected for dimensional and visual conformity before machining to ensure suitability for subsequent processes. During production, in-process inspections are implemented at critical operations, with continuous monitoring of dimensions, geometry and process parameters. Results are documented and traceable in accordance with OEM and IATF quality system requirements, ensuring a fully controlled manufacturing process.








Before moving to the next stage, every finished product undergoes systematic final inspection. Key dimensions, visual quality and function-related characteristics are thoroughly verified to ensure compliance with design requirements and consistent performance.

Before shipment, TOPU carries out strict random inspections based on defined quality standards to ensure batch stability and reliability. All orders undergo final appearance and quantity verification prior to delivery. We also implement strict confidentiality measures by covering customer logos and sensitive information on bulk goods before shipment, preventing brand exposure and protecting our clients' commercial interests.

We do not accept defective products, we do not manufacture defective products, and we do not allow defective products to leave our facility.
Every single product represents our commitment.