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Measureing a shaft’s threads? Not Pro/E

design-engine

design-engine

New member
Not a proe question perse.

I have an existing tangible shaft with a 27mm measured outside thread to outside thread. Is it safe to assume I have a 27mm threaded shaft?I can count the threads.I should be able to guess what threaded lock nut would fit the shaft right?The threads are not looking to good so I was going to purchase a device for measuring the thread count.... hints?
 
Bart .. you need to measure the pitch


the distance btwn thread..


27mm ...coarse ... off the top of my I think is 3mm btwn threads


while fine threads I think is 2mm btwn threads


but it can be a special if it's something different.. maybe someone there in metric land can give you specifics


there is a thing called a thread gage.. Ihave a inch system one .. no mm
 
"Is it safe to assume I have a 27mm threaded shaft?"
if you have mechanical strength in mind,and want to do stress analysis then you can use the mean diameter.or conservatively use the root diameter+stress concentration factor for root of the threads. if you need i can lookup for the stress concentration factor.
 
Bart,

I normally measure the pitch by counting 10 threads and measuring the distance with a caliper. Standard M27 has 3 mm pitch (sometimes called metric coarse) and Metric Fine will be M27 x 1.5, or 1.5 mm pitch. However, it is possible to specify non-standard threads in the metric system, if the application requires it. I'm working on a component that has M7 x 0.8 at the moment, which is both non-standard base size and non-standard pitch.

I believe metric 'cycle' type threads are all 1.0 mm pitch so as not to reduce the net wall-thickness of tube.

All the best,

Rod
 
Bart,

it is not safe to assume you have a metric thread until you do a thread count to narrow down the options. It could very well be 1-1/16" UNEF -18tpi You may also want to check the multiple options for 1-1/16" UNS

At a measured 27mm it is probably too big for

3/4" BSPP - 14tpi
3/4" NPSM - 14tpi

but even a perfect M27 will only measure around 26,8mm across the crests.

Be aware of the variants

M27 x 0,75
M27 x 1,0
M27 x 1,5
M27 x 2,0
M27 x 3,0


DB






Edited by: Dell_Boy
 
It is a Yamaha motorcycle part so Its defiantly metric. Lots of good information here. Ill count the threads next.
Edited by: design-engine
 
Each DIY thread kit over here comes supplied with a thread-identifier-calibre, looking like a set of small combs in a holder. You just selectone and hold it against the profile side of the thread. If it matches the teeth sink all the way to the bottom and you then read what pitch it is. I suppose the same thing exists for non-metric thread. It's the only reliable way to identify pitch.
 
yes Aha it does come in non-metric , got one in my toolbox. It hurts if you try and use it as a comb.





we like to call it inch...not non-metric ... someday you guys will come around and adopt it
smiley2.gif
 
wsylvester said:
yes Aha it does come in non-metric , got one in my toolbox. It hurts if you try and use it as a comb.
Click to expand...


I've lost the need for a comb many, many moons ago ...


wsylvester said:
we like to call it inch...not non-metric ... someday you guys will come around and adopt it
smiley2.gif
Click to expand...


Don't think so, buddy. We'll sooner have a 30-year old pope or americans drinking Belgian beer than that. Hmmm ... well ... maybe the last thing may be sooner than you expected
smiley36.gif
 
americans drinking Belgian beer than that. Hmmm ... well ... maybe the last thing may be sooner than you expected
smiley36.gif






Last time I had a beer was around the last time you used a comb
smiley2.gif



Wondering how long it will be before I'm drinking Jose Daniels.


What can I say, I live in a US town where the 3 major employers are


Swiss, French and Japanense...
smiley36.gif






I have been to Oostende... You have a lovely country
 
French beer ???


I'll use the words a professional-jury-beer-taster once used when asked to comment on Heineken (Dutch) winning a yearly award :


"Gentlemen, this is a nice tasting drink, but it isn't beer ..."


Alex


PS


French should stick to what they know best : wine, champagne, ...
 
I like French Girls. That was my password for 10 years... 'frenchgirls' plural.

By the way the new nut screwd on the bad shaft okay with little need to clean up the threads. I did not tork it down so far and used a lock washer to fold over onto the hex... w/o welding. I was going to just weld the nut to the sprocket.
 
Is there a lot of rivalry between the French and the Belgians? There's a French guy works in our labs and he gets really annoyed when we say he's from Belgium.....
smiley36.gif
 
michael3130 said:
Is there a lot of rivalry between the French and the Belgians? There's a French guy works in our labs and he gets really annoyed when we say he's from Belgium.....
smiley36.gif
Click to expand...


Rivalry ? Wouldn't call it that. But the French have a national feeling, while in Belgium nobody cares. When abroad we'll say we're coming from Belgium, we won't say we ARE Belgian, because there is no such thing. Except in sports, then we find our nationality back.


So I guess he's not too happy to be compared with this pile of anarchists thrown together in what they call a country.


Alex
 
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