On the following tap size 1/2 in. -13 UNC-1A.identify thread meaning for 1A? d. Class of thread e. External C. Coarse or Fine a. Major diameter b. Number of threads per inch of length f. Internal

The tap size "1/2 in. - 13 UNC-1A" provides specific information about the thread characteristics. Let's break down each component:<br /><br />a. **Major diameter**: The major diameter is the nominal size of the thread, which in this case is 1/2 inch.<br /><br />b. **Number of threads per inch of length**: This is indicated by the number "13," meaning there are 13 threads per inch.<br /><br />c. **Coarse or Fine**: The designation "UNC" stands for Unified National Coarse, indicating that the thread is coarse.<br /><br />d. **Class of thread**: The "1A" indicates the class of fit for the external thread. Class 1A is a loose fit, allowing for easy assembly and disassembly.<br /><br />e. **External**: The "A" in "1A" signifies that this is an external thread.<br /><br />f. **Internal**: Since "1A" refers to an external thread, it does not apply to internal threads. Internal threads would be designated with a "B" (e.g., 1B, 2B, 3B).