Ningbo Zhengdu Transmission Appliance Co., Ltd., founded in 1998, is a professional manufacturer of massage chair movements and accessories as well as worms, matched worm gears and helical gears, screw rod and screw set transmission mechanisms, integrating the design, development, production and sales. The company covers an area of 6,000m2 and factory area of 12,000m2, and has 120 employees, including more than 20 senior technology and R&D staff with rich practical experience. 
After ten years of development, the company has 37 sets of CNC equipment, 2 worm milling machines made by Switzerland MZ+LW, 20 cylindrical grinding machines and center-less grinding machines, 41 thread grinding machines, and other complete machining auxiliary equipment and inspection equipment of measuring rooms (gear double-sided gearing combination inspection instruments, gear radial run-out detectors, gear comprehensive gauges, universal tool microscopes, Rockwell hardness testers, surface roughness testers, metallographic analyzers, deflection testers, surface roughness comparison specimens, 3D optical image measuring instruments). 
The production range: Product precision in line with GB-10227-88 GB-10089-88, processing thread modulus 0.3-6, number of threads: 1-10, lead angle range: 2 degress -35degrees, profile angle range 4 degrees-45 degrees, outer diameter: 5mm -60mm, surface hardness HRC20-60, including various materials. Adopting GB-10227-88 standard when the product precision is less than 1 modulus, GB-10089-88 standard when the product precision is more than 1 modulus, single head for 6-9 grade and multi-head for 7-9 grade according to customer demands.