C3 to C7 accuracy grades explained, how load capacity depends on diameter and grade, and the four factors to check when selecting a ball screw.
Two Taiwan brands are commonly encountered in precision transmission. HIWIN (上银) is a Taiwanese precision transmission manufacturer. MOSIONX is the renamed brand of Taiwan Global Transmission, formerly known as TBI; it is also a Taiwanese brand, but a separate company from HIWIN. Shiyi Automation supplies both brands alongside its own selection and integration service.
MOSIONX ball screws are supplied in grades C3 to C7, where C3 is the most accurate. A higher grade gives better positioning and repeatability, and is used where motion accuracy is tight.
Load capacity depends on screw diameter, accuracy grade and material. In general a larger diameter, a higher grade and better material give higher load capacity.
When selecting, choose the diameter and grade to match the actual load so the screw runs within its rating and achieves expected life.
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