How to Measure Threads

Welcome back to Northeast Wisconsin Technical College, today Matt Schmelzer is breaking down the process of measuring threads to make sure they meet specifications.
0:44 Thread specifications
3:11 Referencing the Machinery Handbook for thread inspection
5:23 Using ring gages for thread inspection
7:09 Measuring pitch diameter with a micrometer
9:57 Measuring threads with a micrometer
11:00 Using the three wire method to measure threads
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#maufacturing #machining #metalworking

[@johneric3886]

Nice work good! Good communication skills. I learned a thing or two.

[@TJsoco73579]

As a machine shop inspector, I approve this video.

[@user-yy9uj5bb3v]

Great video! Very clear instruction! Keep em' coming!

[@bearsrodshop7067]

Absolutely what this old hobbyist needed. thx for sharing, been most helpful, Bear

[@hvalles96]

thanks for the instructional video. This will be very helpful, inspecting threading parts.

[@rodneykiemele4721]

Excellent video

[@muhammadmunir9050]

so valuable information if you are working in a machine shop

[@axisfiveraxisfiver5844]

thank you for this!

[@kyriacosvasiliou8342]

I nearly choked on my sandwich when I saw highlighter in the Machinery's Handbook 🤣🤣

[@raider1628]

Would be awesome if you did a video on how to program taper threads and how to read machinery handbook on them.

[@owievisie]

Great, now do one for inside threads because you don't really have measuring tool for that. And I mean big threads like M40x2. What I do is I bore out the hole (with a lathe) to the lowest tolerance (in this case it would be 38mm). Than I would come in with my thread cutter with a full profile cutter and keep cutting away material untill the 38mm get's 0,1 mm bigger. Than I know for sure that I have full thread and within the right tolerance. That is the only way I know and can use to 'measure' the thread Would be cool if someone knows a diffrent way

[@julialuggi1171]

Go/No-Go gages are about the only way I can think of ensuring tolerance on an internal thread. The issue is when cutting a thread manually you don’t know how much more material needs to be removed until the “go” goes. For inspection purposes on CNC runs they are fast and easy. I always rely on experience now when to start checking but when I was starting I referred to thread depth formulas.

[@ryanpatton1795]

@@julialuggi1171 This has been driving me nuts lately as I have some parts I'm making with internal threads that are going to be plated. The last run had some come back from plating that wouldn't fit afterwards even though the H number was "fine". When machining abrasive metals, I'd like to know when the tap wears out so that after plating my threads still work. If you are familiar with metal finishers you obviously get what you pay for. The issue is that for good finishing you need to pay an exorbitant amount for reliable and accurate results which usually isn't viable for most shops budget. I have called our finishers and asked what the tolerance is on their plating and they said "uhh.. like 2 mil?"... The next option is to change finishers which is going to increase lead times by a few weeks or pay the "good" local company 3x the rate to get it done right. Hell, even the cheap company has risen rates and some parts are now double the old rate. We are awaiting quotes from other companies to see what the new difference is so we can reweigh our options. Rant over, I just wish there was an internal thread mic that was like an internal diameter mic with interchangeable anvils I guess. I don't see why it can't be done. The internal thread mic that are available are GIANT for massive threads or insanely expensive for a dedicated thread size (talking like $1k).

[@ryanpatton1795]

If you have an even larger thread than M40 I did see a micrometer that will fit inside for measuring it. Looks like its gotta be a 4 - 5 inch thread though.

[@zackflora6165]

For nuts, I've cut a section then measure with mics or height gage. No one likes this, but if you need more info then a go no go, it's the only thing I've gotten a good msa on.

[@fyougauges]

Thanks for your shairng, Very helpful

[@RandyAce9]

Thank you. Very nice video.

[@gal6537]

Wait how did you get the numbers for largest, best, and smallest wire diam numbers? Someone please explain and dummfy it thanks in advance. GREAT video btw

[@jimhailmann7052]

awesome

[@mrayco]

Very informative thank you

[@impactodelsurenterprise2440]

How about internal threads? Will insert a slightly oversized coil spring with the same pitch with a known wire diameter work?

[@chanchhaychhadanoun7125]

Awesome, can you also do an internal thread video?

[@judesisilangilang4465]

Great video. Is there a formula for NPT? Like what you have here in this video.

[@gregsmith6408]

How do you know which anvil to use. Specifically metric sizes that are not measured in TPI? I have the mics and anvils but unsure which to select?

[@rotarythread]

This is why our tool does all sizes of thread pitch, inch, metric & pipe to make sure one tool will work with almost every thread there is. Let me know if you want to test it out!

[@bobwas4066]

WOW another excellent video! Who makes that micrometer stand?

[@mohdrohaizad9838]

Mitutoyo

[@woodywoods5373]

Excellent video I'm starting to learn how to thread this video gets to the piont without any sarcasm, One question how did you calculate the best pitch wire .57735 thank you.

[@VinhNguyen-cr6pt]

Based on the formula it realized that the best wire diameter is chosen when the wire is tangent with both flanks of the thread form at point that defines the pitch diameter, aka (p/2). if half of the angle of thread is @ (30 degree ...etc) then the formula for best wire diameter (G) is: G = p * tan(@) in which p is pitch length. if @ = 30 degree then tan(@) = 0.57735

[@chrisyboy666]

Machinery handbook 30th is £1500 in the uk can you get in Cheaper in the states

[@ryanpatton1795]

what is the 1.5155 number he has in the 3-wire formula? Is it a constant he got from the wire set chart? The constants I am seeing for that thread size is NOT 1.5155

[@VinhNguyen-cr6pt]

that constant used for different formula, but it come to the same result. Your formula could be like this (60 degree thread angle) : P: Pitch H = P * cos(30) = 0.866 * P; Measured = M = x + 3 * wire => x = M - 3 * wire Pitch Diameter: PD = x + H = x + 0.866 * P = M - 3 * wire + 0.866* P -------------------------------------------------------------------------------------------------- this video use the mean Major Diameter for calculation: mean major diameter: D = x + 2 * .875* H = x + 2 * .875 * 0 .866 * P = x + 1.5155 * P

[@Molly-jh4kz]

Now get a 3A to pass inspection. 😂

[@mohdrohaizad9838]

Use pitch gauge.

[@Aicher-ir1rd]

Bet he’s a laugh a minute down the pub