| 摘要 |
A scriber-compass comprises a pair of first and second arms pivotally connected together at first ends thereof and a threaded rod, having a thumb nut threadably mounted thereon, adapted to selectively pivot the arms relative to each other to set the linear distance between second ends of the arms. A calibrated scale is formed on the rod to visually indicate such linear distance which coincides with the radius of a circle to be scribed on a work piece. A scibing point is formed on the second end of the first arm whereas an automatic punch is mounted on the second end of the second arm for automatically punching a centering hole upon depression of the punch against the workpiece and release of a spring-loaded impact member.
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