unified screw thread


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unified screw thread

[′yü·nə‚fīd ′skrü ‚thred]
(design engineering)
Three series of threads: coarse (UNC), fine (UNF), and extra fine (UNEF); a ¼-inch-diameter (0.006-millimeter) thread in the UNC series has 20 threads per inch, while in the UNF series it has 28.
References in periodicals archive ?
This standard specifies the thread form, series, class, allowance, tolerance, and designation for unified screw threads. This standard only covers UN and UNR threads forms.
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