M112 x 1.5 thread

[ajack1]

I have a part for a briquette machine that I need to reverse engineer. It appears to have a M112 (yes one hundred and twelve) x 1.5 parallel thread on it.

I cannot find any reference to such a thread, does anyone know if it is a standard or better still have any reference to the data for it?

 

[KENAT]

I just took at my ASME B1.13M-2001 (based on the ISO) and it doesn't show M112 as one of the selected threads, not even as a 2nd or 3rd choice.

It could be a special in which case you'd have to get a copy of the relevant BS/ISO and work it out, unless machineries has the information. Although you probably know that already.

How accurately have you been able to inspect it, any chance it's a 4.3750-16 UN thread?

For inch specials I put a FAQ together but I don't think it will be much help, although the thread form is the same. faq404-1480

Posting guidelines faq731-376

http://eng-tips.com/market.cfm?

(probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484​

 

[drawoh]

ajack1,

If you are constantly designing round things that have to assemble, like I do, you wind up specifying threads like that.

Even if the thing is in your handbook, it is not a standard. Your best bet would be to give the mating part to your machine shop so they can use it as a fixture to test whatver they do.

JHG

 

[ajack1]

Thanks for the replies guys.

KENAT, I know the original machine was made in Austria and the OD of the thread measures 112mm -0.1 to -0.05 so I am as certain as I can be that it is not a 4.3750-16 UN thread.

Drawoh, this is really outside of my normal scope of work so it is not something I do all the time and due to circumstances too complicated to try and explain on here it is not possible to provide the mating part to a machine shop.

I was just wondering if anyone had come across this type of thread before and if it was a “standard” for some type of application. Failing that I will get it up on an optical projector and go from there.

Thanks again for the replies.

 

[gearguru]

ajack1,
the PROFILE of the metric thread is perfectly defined by the pitch.
If you are sure that your thread is metric and has 1.5mm pitch, then you can find the rest of its geometry.
It doesn't matter if the thread is M50x1.5 or M500x1.5, the PROFILE dimensions (depth, root radius...) are the same.
If you are sure about the OD, then you can locate that profile on the part so that the OD dimension is met.

 

[mrainey]

the OD of the thread measures 112mm -0.1 to -0.05

Those values make your thread non-standard.

Software For Metalworking

http://closetolerancesoftware.com

 

[ajack1]

Thanks again for the replies.

Gearguru I am aware that all metric threads with a 1.5 pitch have the same profile. But if you put the numbers in the OD should be “down” by .32 not 0.07, which backs up what mrainey says. That is my concern and makes me wonder if it is something other than I think it is.

 

[gearguru]

You obviously have a "non standard" metric thread on hand, if it is metric at all. This situation is nothing unusual. You should check the mating part dimensions to confirm that everything is OK. The OD tolerance is very tight for the 112mm diameter.