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techtalk:ref:tools032 [2022/03/27 01:50] hippysmack [Metric Nut/Bolt Threads] |
techtalk:ref:tools032 [2024/01/23 01:55] (current) hippysmack |
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====== Measuring Threads In General ====== | ====== Measuring Threads In General ====== | ||
+ | **Thread TPI or Pitch**: \\ | ||
You can purchase a cheap template with different size threads to size screws/bolts or go by your local hardware store to use theirs. \\ | You can purchase a cheap template with different size threads to size screws/bolts or go by your local hardware store to use theirs. \\ | ||
But you don't really need one to accurately find the size of most bolts or thread patterns. \\ | But you don't really need one to accurately find the size of most bolts or thread patterns. \\ | ||
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You can buy tap/drill and metric conversion charts pretty cheap online or at some bolt or hardware stores. \\ | You can buy tap/drill and metric conversion charts pretty cheap online or at some bolt or hardware stores. \\ | ||
- | Then hang them up in your shop where you can always find them when needed. \\ | + | Then hang them up in your shop where you can always find them when needed. \\ |
+ | |||
+ | **Bolt/Screw Length**: \\ | ||
+ | Length is measured from the very end of a bolt/screw to where the fastened surface is assumed to be. \\ | ||
+ | Panhead screws / hex bolts / cap screws etc. are measured from under the head to the end. \\ | ||
+ | Flat head screws, tapered shanks under the head, are measured for overall end to end length (head is assumed to end flush with fastened piece). \\ | ||
+ | |||
+ | | Measuring length ((composite of photos used with permission)) | | ||
+ | |{{:techtalk:ref:tools:measuring_different_type_bolts_or_screws.jpg?direct&300|}}| | ||
|SAE thread gauge: ((photos by Hippysmack))||Tap/drill and metric conversion charts.| | |SAE thread gauge: ((photos by Hippysmack))||Tap/drill and metric conversion charts.| | ||
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====== Pitch to TPI Conversion Table ====== | ====== Pitch to TPI Conversion Table ====== | ||
- | |||
The table below is a reprint from THA ((https://traininghandsacademy.com/wp-content/uploads/2020/11/Pitch-mm-to-TPI-inches-Conversion-Table.pdf)) \\ | The table below is a reprint from THA ((https://traininghandsacademy.com/wp-content/uploads/2020/11/Pitch-mm-to-TPI-inches-Conversion-Table.pdf)) \\ | ||
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====== US Nut/Bolt Threads ====== | ====== US Nut/Bolt Threads ====== | ||
- | |||
US threads generally have 3 numbers although the last can be left off unless required. \\ | US threads generally have 3 numbers although the last can be left off unless required. \\ | ||
The first number is a whole number and/or fraction, the second number is the threads per in (TPI), followed by the length in inches. \\ | The first number is a whole number and/or fraction, the second number is the threads per in (TPI), followed by the length in inches. \\ | ||
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====== Metric Nut/Bolt Threads ====== | ====== Metric Nut/Bolt Threads ====== | ||
- | |||
Metric bolts are written down as an "M" followed by 3 numbers and again the last can be left off unless required. \\ | Metric bolts are written down as an "M" followed by 3 numbers and again the last can be left off unless required. \\ | ||
The first number is the diameter, the second the thread pitch, and the third the length in millimeters. ((http://raygirling.com/metthrpt.htm)) \\ | The first number is the diameter, the second the thread pitch, and the third the length in millimeters. ((http://raygirling.com/metthrpt.htm)) \\ | ||
The diameter is the outside diameter of the thread peaks. \\ | The diameter is the outside diameter of the thread peaks. \\ | ||
- | In this example of a 10mm bolt; M10x1.25x35 states that the diameter of the threads is 10mm, the thread pitch is 1.25mm and it's 35mm long. \\ | + | In example of a 10mm bolt; M10x1.25x35 states that the diameter of the threads is 10mm, the thread pitch is 1.25mm and it's 35mm long. \\ |
^{{techtalk:miscres:instruction_sheet_header_4.png?nolink&600|}}||||| | ^{{techtalk:miscres:instruction_sheet_header_4.png?nolink&600|}}||||| | ||
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|**20mm**|0.787|2.50| - | - | | |**20mm**|0.787|2.50| - | - | | ||
|**24mm**| |3.00| - | - | | |**24mm**| |3.00| - | - | | ||
+ | |||
+ | **Methods of measuring in pics**: \\ | ||
+ | Metric screw thread OD can be deduced by using an imperial (US) scale caliper using the chart above. \\ | ||
+ | Your measurements may not be an exact match to the dims above but will be close enough to make a judgement on the metric counterpart size. \\ | ||
+ | |||
+ | {{:techtalk:ref:tools:measuring_metric_screw_threads_by_hippysmack.jpg?direct&300|}} ((photo by Hippysmack)) {{:techtalk:ref:tools:measuring_screw_pitch_by_hippysmack.jpg?direct&300|}} ((photo by Hippysmack)) \\ | ||
====== Common Brake Line Threads ====== | ====== Common Brake Line Threads ====== | ||
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====== NPT Pipe Threads ====== | ====== NPT Pipe Threads ====== | ||
- | NPT stands for National Pipe Thread. Descriptions are commonly used as either straight (NPS) or tapered (NPT). ((DR DICK of the XLFORUM http://xlforum.net/forums/showthread.php?t=1810036&highlight=tap+die&page=2)) \\ | + | NPT stands for National Pipe Thread. Descriptions are commonly used as either straight (NPS) or tapered (NPT). ((DR DICK of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/168660-any-thread-experts-around/page2?t=1810036&highlight=tap+die&page=2)) \\ |
Pipe thread sizes do not refer to any physical dimension. \\ | Pipe thread sizes do not refer to any physical dimension. \\ | ||
NPT has flattened peaks and troughs where BSP is rounded. NPT has a thread angle of 60º where BSP is 55º. \\ | NPT has flattened peaks and troughs where BSP is rounded. NPT has a thread angle of 60º where BSP is 55º. \\ | ||
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** Little known fact**: \\ | ** Little known fact**: \\ | ||
- | All iron heads pipe threads used in cases, rocker boxes, and oil pumps are straight female thread, fitted with tapered thread male fittings.((DR DICK of the XLFORUM http://xlforum.net/forums/showthread.php?t=1810036&highlight=tap+die&page=2)) \\ | + | All iron heads pipe threads used in cases, rocker boxes, and oil pumps are straight female thread, fitted with tapered thread male fittings.((DR DICK of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/168660-any-thread-experts-around/page2?t=1810036&highlight=tap+die&page=2)) \\ |
This holds true for Evo Sportsters also. \\ | This holds true for Evo Sportsters also. \\ | ||
- | * The sizes in the chart below are the major dia of the male straight thread (as the pipe OD is the major). \\ And the major dia. of a tapered male thread at it's big end. ((DR DICK of the XLFORUM http://xlforum.net/forums/showthread.php?t=1810036&highlight=tap+die&page=2)) | + | * The sizes in the chart below are the major dia of the male straight thread (as the pipe OD is the major). \\ And the major dia. of a tapered male thread at it's big end. ((DR DICK of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/168660-any-thread-experts-around/page2?t=1810036&highlight=tap+die&page=2)) |
- | * The tapered thread has it's diameter reduced on a taper of .0625" per inch of thread length. Almost all hardware store fittings will be tapered thread.((DR DICK of the XLFORUM http://xlforum.net/forums/showthread.php?t=1810036&highlight=tap+die&page=2)) | + | * The tapered thread has it's diameter reduced on a taper of .0625" per inch of thread length. Almost all hardware store fittings will be tapered thread.((DR DICK of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/168660-any-thread-experts-around/page2?t=1810036&highlight=tap+die&page=2)) |
^{{techtalk:miscres:instruction_sheet_header_4.png?nolink&600|}}|||| | ^{{techtalk:miscres:instruction_sheet_header_4.png?nolink&600|}}|||| |