Standard accuracy grades are defined by ISO 3408-3 which categorizes accuracy classes based on lead error at full length of travel (deviation) and permissible lead error along the path of travel (variation).
- Standard accuracy for inch series screws is: ±.004 in/ft lead accuracy which is equal to T10 tolerance class per ISO 3408-3 classification
- Standard accuracy for the metric series with OD ≤ 12mm is 52µm/300mm which is a T7 tolerance class
- Standard accuracy class for metric series with OD > 12mm is 23µm/300mm with is a P5 tolerance class.