As a training Calibration Technician, I found this to be a helpful aid in the procedure of Pitch Diameter measurement, using the three wire method. Thank you, it was very interesting...
Great video. I could never quite work out how to use the wire method. You did a good job explaining how it is done. and you have another subscriber. best to you. Earl
Love the video. Learned something new. Don't know if it was pointed out yet but at the 1.20 mark you showed the formula for calculating the largest wire but in the comments you wrote "Smallest". Thank you for the video
Calculation for preferred wire diameter is [ Pitch OVER 2x(COSxhalf the included thread angle e.g. 30 degrees) ] . Using this calculation for a M40 thread with a 3.5mm pitch I calculated roughly a 2.02mm wire. Does that seem correct?
Mistakes and omissions here. .895 is NOT the maximum size of a 7/8-9 2A thread as machined and before plating. Before plating the max is .8937 and after plating it is max .8956. So that screw is acceptable only because it is plated. This method is only suitable for class 3A threads and plated class 2A threads but in either case it does not indicate what undersize is. Neither does it indicate what the plating allowance is. It is not necessary that the wires contact the pitch diameter line, anywhere in the V that is straight and where the wire still protrudes will give equal results.
The measurement taken over the wires when used in a specific formula will tell you the pitch diameter. The wires do not necessarily contact ( tangent to) the thread profile at the pitch diameter. Any wire that would conform to that statement would be too small in diameter to project above the crest of the thread.
Someone smarter than me figured out a wire of a certain diameter relative to the pitch of a thread would contact the thread at the pitch diameter and protrude beyond the outside of the thread making measurement possible.
I'm glad there are people out there who are interested in this.. to me it's Chinese!!! lol actually I got the first part.. then completely lost interest since I came here wondering why 3 wires were used instead of just 1 wire wrapped around the thread but I guess bending the wire would change the measurement.. especially on smaller bolts.
Being a bit pedantic but the wires will not always touch the thread on the pitch diameter. That is Ok as the formula still gives the correct result for the measurement. The best wire will touch exactly on the pitch diameter, smaller wires will touch a bit deeper in the thread and larger wires will touch a bit further out.
yes. I'd like to be more familiar with this measuring method when we make threads. you know, you have to cut more deaper when you don't get the exact pitch diameter. if you have time. any way thanks for great video. Nik
The math will change depending on the thread you are measuring. Is your thread 7/8" outside diameter? (male) is it 9 threads per inch (course thread)? Are the three wires your using all .063"? If all of these are correct your thread is cut too deep. Please let me know how you make out with this. Thanks for your note.
What's your take on the calibration of go screw plug gages? I currently use a ULM 600 and 3 wire measuring technique like in your video. Although the calculations and chosen wire sizes are built into the software. We are considering something maybe less accurate but still a pass/fail scenario in the way of snap ring gages, set using master plug gages. would these suffice? As in would they show enough indication of wear as to find non-conforming screw plug gages that didn't have obvious signs of damage/wear? Thank you.
I like snap gauges as they are less technical to use..(low skilled operators). As for accuracy, I'm nor sure how tight your tolerances are but they work well for most situations. As for wear, schedule regular calibration and you shouldn't have an issue. Thanks for asking.
machiningmoments Thanks for the reply, I'm currently looking at a Tri-roll gage comparator. Have you thoughts / prior experience with them at all? so far it looks ideal as it's also portable.
I have used one that is spring loaded and has a dial indicator on the comparator , I like it...it works fine. You need a different set of gauges for each pitch, threads per inch. So I guess my opinion is if you can justify the cost it is a nice tool to have. Thanks for asking. Good luck!
Hello! I applied the formula to get the MOW in a M5X0.5-6H plug gage but somehow it does not match my program for calculating this. My programs show the MOW to be 5.112-.005 but with the formula I don't get that number, any advice? Thank you!
I got 5.61mm (max). What wire size are you using? (.4572)? D=5mm G=.4572mm the 1.5155 is multiplied by the pitch because it is metric. Pitch= .5mm Hope that helps.
@@machiningmoments Thank you for the response. I found out another way for Metric gages that worked well for me. This is what I got MOW=PD(Pitch Diameter+C(Constant). In this case with an M5X.5-6H the PD is 4.675 plus the C being .4330 comes to be 5.108+.005 this matched my programs. I am using Mitutoyo Thread Measuring Wires for .5mm pitch, the size of the wire came to be .2887mm. Thank you for the video, it helped a lot teaching new employees.
Thanks But .875+.189=1.064 1.5155/9=.1683888 or round to .168 or to .1684 I am getting .996 or .9956 Not that .0005 matters much unless one is grinding a ball lead screw, but still I Wonder why we are not the same? Is it that the male has to be a slip fit smaller than the female? And zero fit would never go?
I am assuming you are questioning why use the math of three wires when you measure straight across. The formula factors in the three wires making a triangle at the pitch diameter.
@@machiningmoments actually I want to know if the formula should be interpreted as we do in typical math problems. My wire set says "3w" . I was taught that this means 3 times the variable/unknown. Thanks for the help.
I believe in this case it is 3 times the wire you are using. The w is the wire diameter you are using from your kit. G is the same as the w, that is the way it is presented in the handbook. Good luck Rev2
Assuming you don't have a chart for a wire set, google "pitch diameter wire chart images". It is .040" wires for 16 TPI. The formula I use is M = D + 3G - 1.5155/N. M = Measurement over the wire (must be larger than the OD of the thread, D = nominal diameter in your case 2.875", G = diameter of the wire you are are using (W works also) in your case .040", N is the number of threads per inch which is 16. So if we crunch the numbers we get 2.900" like you said. Now this is the top size of a class three fit (assuming you are cutting a unified thread). You would then look in the machinery handbook and see how much smaller a class 2 or 1 would be. I hope this makes sense Rev2?
As a training Calibration Technician, I found this to be a helpful aid in the procedure of Pitch Diameter measurement, using the three wire method. Thank you, it was very interesting...
Best video I've found so far on this. Thank you
+eddie kalbach Thanks Eddie, I appreciate your comment. Thanks for watching.
Thank you thank you thank you. Best explanation I’ve come across to explain the pitch diameter and how to measure
Thanks Daniel, I'm glad it was helpful.
Great video. I could never quite work out how to use the wire method. You did a good job explaining how it is done.
and you have another subscriber.
best to you.
Earl
Love the video. Learned something new. Don't know if it was pointed out yet but at the 1.20 mark you showed the formula for calculating the largest wire but in the comments you wrote "Smallest". Thank you for the video
I'm glad you liked it. Thank you for taking the time to leave a message and watch the video. I'll have a look at 1:20.
I agree, this is my favorite way to measure threads. Thank you for your post.
Glad you liked it, it is my favorite way to measure threads. Thanks for your post.
Very good explanation! This helped me a lot.
I'm glad it was helpful. Thank you for watching.
great video! I knew about this but not how to do it thank you very much.
Thanks, I'm glad it was useful! I appreciate your comment!
Thanks for the video
Best explanations I enjoyed it
I'm glad you found it helpful. Thank you for watching and leaving a comment.
@@machiningmoments if I had the chance I would stick to you and learn everything as I can .thank you sir
This is kinda funny explained. I make thread Gage's for a living. We go really in depth with this.
Thanks, yes I have. These are the ones that were available to me.
I'm glad it was helpful, thank you for your comment!
Calculation for preferred wire diameter is [ Pitch OVER 2x(COSxhalf the included thread angle e.g. 30 degrees) ] . Using this calculation for a M40 thread with a 3.5mm pitch I calculated roughly a 2.02mm wire.
Does that seem correct?
Mistakes and omissions here. .895 is NOT the maximum size of a 7/8-9 2A thread as machined and before plating. Before plating the max is .8937 and after plating it is max .8956. So that screw is acceptable only because it is plated. This method is only suitable for class 3A threads and plated class 2A threads but in either case it does not indicate what undersize is. Neither does it indicate what the plating allowance is.
It is not necessary that the wires contact the pitch diameter line, anywhere in the V that is straight and where the wire still protrudes will give equal results.
Glad you liked it, thanks for your post.
The measurement taken over the wires when used in a specific formula will tell you the pitch diameter. The wires do not necessarily contact ( tangent to) the thread profile at the pitch diameter. Any wire that would conform to that statement would be too small in diameter to project above the crest of the thread.
Someone smarter than me figured out a wire of a certain diameter relative to the pitch of a thread would contact the thread at the pitch diameter and protrude beyond the outside of the thread making measurement possible.
I will have to dig deeper into your reply. I can't see it happening if the wire contact is truly tangent to the pitch diameter.
Hi Joe, let me know what you discover please, that is my understanding of how it works.
I will. I am intrigued as well. I'll run it on my CAD system and see how much wiggle room there really is.
@@joepie221 Interested to hear any more info or feedback also. I use this video and your's Joe in my classes :)
I'm glad there are people out there who are interested in this.. to me it's Chinese!!! lol actually I got the first part.. then completely lost interest since I came here wondering why 3 wires were used instead of just 1 wire wrapped around the thread but I guess bending the wire would change the measurement.. especially on smaller bolts.
These wires are fairly hard and wouldn't bend very easy.
Some great info here! Thanx. :)
+Kostas stamatakos I'm glad it was useful. Thanks for watching!
I'm glad it was the same, thanks.
Being a bit pedantic but the wires will not always touch the thread on the pitch diameter. That is Ok as the formula still gives the correct result for the measurement. The best wire will touch exactly on the pitch diameter, smaller wires will touch a bit deeper in the thread and larger wires will touch a bit further out.
You are correct, they fall within the acceptable range.
great explanation. please add the case for thread cutting to this one.
thanks a lot.
Nik
Hi Nik, you would like a video on thread cutting?
yes. I'd like to be more familiar with this measuring method when we make threads. you know, you have to cut more deaper when you don't get the exact pitch diameter.
if you have time.
any way thanks for great video.
Nik
good video. well explained..
thank you. it is clear to the point.
Neill Mikha Glad it helped, thanks for stopping by!
The math will change depending on the thread you are measuring. Is your thread 7/8" outside diameter? (male) is it 9 threads per inch (course thread)? Are the three wires your using all .063"? If all of these are correct your thread is cut too deep. Please let me know how you make out with this. Thanks for your note.
Very well done vid! Have you ever heard the pitch diameter wire set called a "Pee Dee" set?
i know there's PEMDAS but you should put parenthesis in the formulas to avoid confusion
Good point BEDMAS would help, thanks for the reminder.
Nice tutorial. But, where does the number 1.5155 come from?
+Kuei 12 It is a constant that is factored in to the three wire formula.
The largest , best and smallest wire is remains the same for all sizes of thread measurement?How do you get that result?
+Suki Chin The wire "contacts at the pitch diameter" the extra size is added to the outside measurement.
What's your take on the calibration of go screw plug gages? I currently use a ULM 600 and 3 wire measuring technique like in your video. Although the calculations and chosen wire sizes are built into the software.
We are considering something maybe less accurate but still a pass/fail scenario in the way of snap ring gages, set using master plug gages.
would these suffice? As in would they show enough indication of wear as to find non-conforming screw plug gages that didn't have obvious signs of damage/wear? Thank you.
I like snap gauges as they are less technical to use..(low skilled operators). As for accuracy, I'm nor sure how tight your tolerances are but they work well for most situations. As for wear, schedule regular calibration and you shouldn't have an issue. Thanks for asking.
machiningmoments Thanks for the reply, I'm currently looking at a Tri-roll gage comparator. Have you thoughts / prior experience with them at all? so far it looks ideal as it's also portable.
I have used one that is spring loaded and has a dial indicator on the comparator , I like it...it works fine. You need a different set of gauges for each pitch, threads per inch. So I guess my opinion is if you can justify the cost it is a nice tool to have. Thanks for asking. Good luck!
Hello! I applied the formula to get the MOW in a M5X0.5-6H plug gage but somehow it does not match my program for calculating this. My programs show the MOW to be 5.112-.005 but with the formula I don't get that number, any advice? Thank you!
I got 5.61mm (max). What wire size are you using? (.4572)? D=5mm G=.4572mm the 1.5155 is multiplied by the pitch because it is metric. Pitch= .5mm
Hope that helps.
@@machiningmoments Thank you for the response. I found out another way for Metric gages that worked well for me. This is what I got MOW=PD(Pitch Diameter+C(Constant). In this case with an M5X.5-6H the PD is 4.675 plus the C being .4330 comes to be 5.108+.005 this matched my programs. I am using Mitutoyo Thread Measuring Wires for .5mm pitch, the size of the wire came to be .2887mm.
Thank you for the video, it helped a lot teaching new employees.
thanq very much it did a grt help to me
Thank you
A little irony: The people who make measuring tools misspelled measuring on the thread wires. :)
Subscribed!
+J Mac Thanks!
pl explain 0.57735/N, it is formula or calculation
It is a formula used that gives you the correct size for the wire used for the required pitch (1/N). It is derived from trig.
Gauges work great but they don't tell actual size.
I have been threading for 35 years. Try wire measuring a 120 pitch. The wires are like hair.
+bigbadbruins1 Not sure I could see them anymore.
are you use rachet?
You should, it
you need a pratt and whitney supermic. much easier than a micrometer ;)
+Daniel Guay Definitely easier!
Thanks
But .875+.189=1.064
1.5155/9=.1683888 or round to .168 or to .1684
I am getting .996 or .9956 Not that .0005 matters much unless one is grinding a ball lead screw, but still I Wonder why we are not the same? Is it that the male has to be a slip fit smaller than the female? And zero fit would never go?
thank u so much guru
Glad to help.
it is very helpful
I'm glad, thank you for saying so.
I was greatly pleased with the beginning of this video but was greatly disappointed at the end.
Why?
machiningmoments i'm sure he couldn't explain.
3G = 3x .063=.189 ?
I am assuming you are questioning why use the math of three wires when you measure straight across. The formula factors in the three wires making a triangle at the pitch diameter.
@@machiningmoments actually I want to know if the formula should be interpreted as we do in typical math problems. My wire set says "3w" . I was taught that this means 3 times the variable/unknown. Thanks for the help.
I believe in this case it is 3 times the wire you are using. The w is the wire diameter you are using from your kit. G is the same as the w, that is the way it is presented in the handbook. Good luck Rev2
@@machiningmoments in my case I'm cutting 2-7/8-16. Using the .04 set pd= 2.830
Found an online calculator . I was given 2.900 over the wires.
Assuming you don't have a chart for a wire set, google "pitch diameter wire chart images". It is .040" wires for 16 TPI. The formula I use is M = D + 3G - 1.5155/N. M = Measurement over the wire (must be larger than the OD of the thread, D = nominal diameter in your case 2.875", G = diameter of the wire you are are using (W works also) in your case .040", N is the number of threads per inch which is 16. So if we crunch the numbers we get 2.900" like you said. Now this is the top size of a class three fit (assuming you are cutting a unified thread). You would then look in the machinery handbook and see how much smaller a class 2 or 1 would be. I hope this makes sense Rev2?
Also the manufacturers of the measuring wires doesn't know how to spell lolololoooooloo
I caught that also. I guess not everything translates into English!
Thank you