EXAMPLE: HOW TO USE THE THREAD MILL LOCATOR
LINE NUMBERPAGE NUMBERLOCATION OF ALL THREAD MILLS THAT WILL CUT THE 3/8-20 THREADTHREAD SIZEROW LOCATION
ALL THREAD MILLS IN LINE #50 WILL ALSO CUT THE 7/16-20 THREAD
#50 3/8-20 5AE, 6AK, 7A, 7AB, 13L, #40
#50 3/8-20 5AE, 6AK, 7A, 7AB, 13L, #40
THREAD MILLS #51 3/8-24 5AF, 6AH, 6AL, 7B, 7AC, 13L, #41 #52 3/8-27 5AG, 6AM, 7AD, 13 I -13L #53 3/8-28 7C, 13L, #43 #54 3/8-32 5AH, 6AN, 7D, 13L, #44 #55 3/8-36 7E, 13L, #45 #56 3/8-40 7F, 13L, #46 #57 .390-27 # 52 #58 7/16-14 5AI, 6A I , 6AO, 7Y, 13L #59 7/16-16 7G, #48 #60 7/16-18 5AJ, 6AP, 7H, #49 #61 7/16-20 5AK, 6AQ, 6BG, 7 I , #50
#61 7/16-20 5AK, 6AQ, 6BG, 7 I , #50
To find a thread mill to cut a 7/16-20 internal thread, simply look for the 7/16-20 in the chart. It’s located on line #61. Line #61 lists several location numbers. These numbers will show all the tools available to produce this thread. The location numbers on line #61 are 5AK, 6AQ, 6BG, 7I, #50. The first number indicates the page in the catalog where the tool is found. For 5AK, look on catalog page 5 and then search for 5AK. The letters follow alphabetically down the columns. The 6AQ, 6BG and 7I are more options for cutting the 7/16-20 thread. Notice the #50 located at the end of line #61. This indicates that Line #50 lists more thread mills that will cut the 7/16-20 thread. The tools in line #50 will cut both the 3/8-20 and the 7/16-20 internal threads. Why use the 3/8-20 thread mill for cutting a 7/16-20 thread? Although the 7/16-20 is larger and stronger, the smaller thread mill will allow for better chip evacuation and better coolant penetration. Also, the smaller thread mill will run at a higher RPM for the designated Surface Feet Per Minute (SFPM). Both would be an excellent choice. If the thread mill is small and the length of thread deep, always use the largest tool available. For larger thread sizes with more favorable length-to-diameter ratios, a smaller size thread mill of the same pitch can be used quite effectively. 2
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