The Change Nut can easily transform linear motion into rotary motion and vice versa at an efficiency of 70% because it has a lead angle on the sliding surface as large as 45 degrees. It is suitable to gain obtaining a fast traveling mechanism at a low speed because of its large lead. The Miniature Change Nut, formed from oil containing plastic, is resistant to wear and has excellent lubricating properties without greasing. In addition, it is virtually maintenance free because it retains the properties for a long time.