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techtalk:ref:tools030 [2021/01/27 23:24] – hippysmacktechtalk:ref:tools030 [2023/12/20 16:33] (current) – hippysmack
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 ====== REF: Tools & Fasteners ====== ====== REF: Tools & Fasteners ======
 ====== General Drilling and Tapping ====== ====== General Drilling and Tapping ======
-\\ 
-===== Thread Tolerance ===== 
- 
-Threads can be cut to a tighter or looser fit depending on the needs or sometimes availability of drill bit sizes. For instance, drill bits are available in a wide variety of sets or kits. The most common sizes are usually the ones that are provided. However, many suppliers carry a drill index kit which comes with a huge amount of drill bits in step sizes. Some are in 1/32 steps and some are in one thousandths increments. So, if you want a close tolerance fit on a 3/8"x16 threaded connection, you could use a 0.2969" pre-drill or for a looser fit you could use a 0.3230" pre-drill. Even with a standard 0.3125" drill bit, a hand drill is not going to produce a straight hole every time. If you have to over compensate with it and wallow out the hole just a bit to get it straight, you may be producing a looser threaded connection without realizing it. Care should be taken on tighter pre-drilled holes since it creates more friction and heat when tapping than a standard or slightly larger hole and it can lead to breaking taps off in the hole or cracking the piece you're working on. ((hippysmack from the XLFORUM)) 
- 
 \\ \\
  
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 Back them out, clean and re-lube them periodically to minimize any loose particles getting loose in your work area. \\ Back them out, clean and re-lube them periodically to minimize any loose particles getting loose in your work area. \\
 This also helps to control heat buildup. \\ This also helps to control heat buildup. \\
-|  Lubing bits. ((photos by sifty of the XLFORUM http://xlforum.net/forums/showthread.php?t=1592463&page=5))  |||+|  Lubing bits. ((photos by sifty of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/146604-first-harley-1975-xl1000-caf%C3%A9-project/page5?t=1592463&page=5))  |||
 |{{techtalk:ref:tools:lubing_bits_1_by_sifty.jpg?direct&300|}}|{{techtalk:ref:tools:lubing_bits_2_by_sifty.jpg?direct&300|}}|{{techtalk:ref:tools:lubing_bits_3_by_sifty.jpg?direct&300|}}| |{{techtalk:ref:tools:lubing_bits_1_by_sifty.jpg?direct&300|}}|{{techtalk:ref:tools:lubing_bits_2_by_sifty.jpg?direct&300|}}|{{techtalk:ref:tools:lubing_bits_3_by_sifty.jpg?direct&300|}}|
 +
 ===== Make a Pilot Hole Before Drilling ===== ===== Make a Pilot Hole Before Drilling =====
  
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 ====== Tapping ====== ====== Tapping ======
-Make sure to use sharp tap and dies. ((Shadowdog500 of the XLFORUM http://xlforum.net/forums/showthread.php?t=221093&highlight=split+rocker+box)) \\+Make sure to use sharp tap and dies. ((Shadowdog500 of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/51523-question-about-my-rocker-oil-lines?t=221093&highlight=split+rocker+box)) \\ 
 + 
 +===== Thread Tolerance ===== 
 +Threads can be cut to a tighter or looser fit depending on the needs or sometimes availability of drill bit sizes. For instance, drill bits are available in a wide variety of sets or kits. The most common sizes are usually the ones that are provided. However, many suppliers carry a drill index kit which comes with a huge amount of drill bits in step sizes. Some are in 1/32 steps and some are in one thousandths increments. So, if you want a close tolerance fit on a 3/8"x16 threaded connection, you could use a 0.2969" pre-drill or for a looser fit you could use a 0.3230" pre-drill. Even with a standard 0.3125" drill bit, a hand drill is not going to produce a straight hole every time. If you have to over compensate with it and wallow out the hole just a bit to get it straight, you may be producing a looser threaded connection without realizing it. Care should be taken on tighter pre-drilled holes since it creates more friction and heat when tapping than a standard or slightly larger hole and it can lead to breaking taps off in the hole or cracking the piece you're working on. ((hippysmack from the XLFORUM)) 
 + 
 +\\
  
 ===== Removing a Broken Tap ===== ===== Removing a Broken Tap =====
-  * The best way to remove a broken carbon steel tap is to use a small hole punch to the center of the broken tap and smack it with a hammer while exploding the hardened tap. You don't stand a chance at drilling it out without damaging the hole/ threads and chances are since pressure was enough to break the tap, it'll take more pressure than that to remove the broken lil stubby that's left. ((hippysmack)) ((Article by Oldrump1 [[http://xlforum.net/forums/showthread.php?t=1959533]]))+  * The best way to remove a broken carbon steel tap is to use a small hole punch to the center of the broken tap and smack it with a hammer while exploding the hardened tap. You don't stand a chance at drilling it out without damaging the hole/ threads and chances are since pressure was enough to break the tap, it'll take more pressure than that to remove the broken lil stubby that's left. ((hippysmack)) ((Article by Oldrump1 [[https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-general-discussion-and-problems/181908-assembly-prep?t=1959533]])) 
 + 
 +===== SAE and Metric Tap Drill Sizes ===== 
 + 
 +Below are standard pre-drill sizes for size taps used. These are common drill sizes and they are sufficient for most applications on a Sportster. ((Starrett tap drill sizes chart unless otherwise noted)) 
 + 
 +^  SAE Tap  ^  Drill Size  ^  Drill Bit  | ^  Metric Tap  ^  Drill Bit  | 
 +^  Thread size   ^  #/Letter  ^  Diameter- in  | ^  Thread Size  ^  Diameter- mm / in  | 
 +|6x32  |  36  |0.1065" ^ |M3 x 0.5 |2.50 mm / 0.0984"   | 
 +|#6x40  |  33  |0.1130"  ^ |M3.5 x 0.6 |2.90 mm / 0.1142"   | 
 +|#8x32 \\ #8-36  |  29  |0.1360"  ^ |M4 x 0.7 |3.30 mm / 0.1299"  | 
 +|#10x24  |  25  |0.1495"   ^ |M4.5 x 0.75 |3.70 mm / 0.1457"   | 
 +|#10x32  |  21  |0.1590"   ^ |M5 x 0.8 |4.20 mm / 0.1654"   | 
 +|#12x24  |  16  |0.1770"   ^ |M6 x 1 |5.00 mm / 0.1968"  | 
 +|#12x28  |  14  |0.1820"   ^ |M7 x 1 |6.00 mm / 0.2362"  | 
 +|1/4"x20  |  7  |0.2010"   ^ |M8 x 1.25 |6.70 mm / 0.2638"  | 
 +|1/4"x28  |  3  |0.2130"   ^ |M8 x 1 |7.00 mm / 0.2756"  | 
 +|5/16"x18  |  F  |0.2570"  ^ |M10 x 1.5 |8.50 mm / 0.3346"  | 
 +|5/16"x24  |  I  |0.2720"  ^ |M10 x 1.25 |8.70 mm / 0.3425"  | 
 +|3/8"x16  |  5/16  |0.3125"  ^ |M12 x 1.75 |10.20 mm / 0.4016"  | 
 +|3/8"x24  |  Q  |0.3320"  ^ |M12 x 1.25 |10.80 mm / 0.4252"  | 
 +|7/16"x14  |  U  |0.3680"  ^ |M14 x 2 |12.00 mm / 0.4724"  | 
 +|7/16"x20 |  25/64  |0.3906"  ^ |M14 x 1.5 |12.50 mm / 0.4921"  | 
 +|1/2"x13  |  27/64  |0.4219"  ^ |M16 x 2 |14.00 mm / 0.5512"  | 
 +|1/2"x20  |  29/64  |0.4531"  ^ |M16 x 1.5 |14.50 mm / 0.5709"  | 
 +|9/16"x12  |  31/64  |0.4844"  ^ |M18 x 2.5 |15.50 mm / 0.6102"  | 
 +|9/16"x18  |  33/64  |0.5156"  ^ |M18 x 1.5 |16.50 mm / 0.6496"  | 
 +|5/8"x11  |  17/32  |0..5312"  ^ |M20 x 2.5 |17.50 mm / 0.6890"  | 
 +|5/8"x18  |  37/64  |0.5781"  ^ |M20 x 1.5 |18.50 mm / 0.7283"  | 
 +|3/4"x10 |  21/32  |0.6562"  ^ |  
 +|3/4"x16 |  11/16  |0.6875"  ^ | 
 +|7/8"x9  |  49/64  |0.7656"  ^ | 
 +|7/8"x14 |  13/16"  |0.8125"  ^ | 
 +|1"x8  |  7/8"  |0.8750"  ^ | 
 +|1"x12 |  59/64"  |0.9219"  ^ | 
 +|1"x14 |  15/16  |0.9375"  ^ | 
 + 
 +====== NPSC Tap Drill Sizes ====== 
 + 
 +^Tap / Thread Size  ^Drill Size ((Starrett tap drill sizes chart)) | 
 +|1/8-27  |11/32  | 
 +|1/4-18  |7/16  | 
 +|3/8-18  |37/64  | 
 +|1/2-14  |23/32  | 
 +|3/4-14  |59/64  | 
 + 
 +====== Slotting Holes ====== 
 + 
 +{{:techtalk:ref:tools:enlarging_holes_by_hippysmack.png?direct&400|}} ((drawing by Hippysmack)) \\
  
  

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