tolerance on external diameter thread screw m16

[Sleepers]

Good morning.
I ask for your opinion if possible.

We usually purchase from galvanized threaded stems m16 (big pass, 2 mm), length 98 mm., code 302625.
these, in practice:

https://www.elesa.com/productdispla...me=catalogentrypage&langid=-4&catalogid=10058

https://www.elesa.com/siteassets/pdf/pdf_it/sm..pdf

mating them (for example to a nut m16) we have noticed (spannometrically) that there is much game; verifying and measuring more precisely the outer diameter of the stem m16 we find a value of 15,6 mm and we are trying to understand, tables of the baldassini to the hand, if this measure is acceptable or not.

we have speculated that the thread is in tolerance class 6g (average quality, "easy screw current applications, with galvanic protection").

is it correct to use the formula for calculating limit diameters (baldassini, chapter tables, iso threads with triangular profile, table 6)?
dmax = dnom - (es/1000)
dmin = dnom - ((es+td)/1000)

according to the above, we come out (if we did not wrong) a dmin of 15,682, so the pieces would be out of tolerance.

What do you think?
Thank you.

 

[falonef]

external diameter of the stem 15,6 for a thread m16 seems to me little . . . . but perhaps I am mistaken

 

[Sleepers]

external diameter of the stem 15,6 for a thread m16 seems to me little . . . . but perhaps I am mistaken

It is our own impression, by the nose, but to complain with the supplier I wanted to have some more objective data, from here the rubbing on the tables

 

[TETRASTORE]

according to the above, we come out (if we did not wrong) a dmin of 15,682, so the pieces would be out of tolerance.

corresponds to the minimum value indicated by Standard.
if you are certain that the detected diameter is 15.600, it is out of range and you can contest it; first you should measure it with a m16 6g ring caliber.
it is not excluded that it is only a lot of pieces of that supplier; you better compare directly to the manufacturer's technical service.

 

[meccanicamg]

above all it is not said that it is in tolerance 6g. check very well what the catalog says before contesting. the calculation of tolerances that is.

 

[Sleepers]

corresponds to the minimum value indicated by Standard.

thanks to the link; I had not found that document with the size already ready to consult, so I had made the calculations by hand. I comforted to see that the value I found (15,682) corresponds, I was afraid I had something wrong

if you are certain that the detected diameter is 15.600, it is out of range and you can contest it; first you should measure it with a m16 6g ring caliber.
it is not excluded that it is only a lot of pieces of that supplier; you better compare directly to the manufacturer's technical service.

Yes, the diameter detected is that, on all pieces.

we are evaluating how to move; for now we have mentioned the problem only to our retailer who is being informed.
the feet, screwed, "ballan", but do not trouble; before contesting the pieces we will verify if the class is really 6g, and in case we will also get a ring caliber.

Thank you.

 

[Sleepers]

above all it is not said that it is in tolerance 6g. check very well what the catalog says before contesting. the calculation of tolerances that is.

In fact, mine is only a guess that must be verified.
on the site and on the catalog I did not find the class of tolerance of the thread, in case we will hear the technical office Elesa.

Thank you!

 

[Marco F inox]

Good morning.
I ask for your opinion if possible.

We usually purchase from galvanized threaded stems m16 (big pass, 2 mm), length 98 mm., code 302625.
these, in practice:

https://www.elesa.com/productdispla...me=catalogentrypage&langid=-4&catalogid=10058

https://www.elesa.com/siteassets/pdf/pdf_it/sm..pdf

mating them (for example to a nut m16) we have noticed (spannometrically) that there is much game; verifying and measuring more precisely the outer diameter of the stem m16 we find a value of 15,6 mm and we are trying to understand, tables of the baldassini to the hand, if this measure is acceptable or not.

we have speculated that the thread is in tolerance class 6g (average quality, "easy screw current applications, with galvanic protection").

is it correct to use the formula for calculating limit diameters (baldassini, chapter tables, iso threads with triangular profile, table 6)?
dmax = dnom - (es/1000)
dmin = dnom - ((es+td)/1000)

according to the above, we come out (if we did not wrong) a dmin of 15,682, so the pieces would be out of tolerance.

What do you think?
Thank you.

the excessive game that laments between nut and screw, has no relation with the outer diameter of the screw. what you need to check is the width and depth of the thread throat.
to do this control you have to use the three cylinders of diameter proportional to the pitch and charts, inserted two on one side and one on the other, measure with micrometer to plate their perpendicular width to the axis. the quota detected, will certainly be out of tolerance.

 

[Marco F inox]

Good morning.
I ask for your opinion if possible.

We usually purchase from galvanized threaded stems m16 (big pass, 2 mm), length 98 mm., code 302625.
these, in practice:

https://www.elesa.com/productdispla...me=catalogentrypage&langid=-4&catalogid=10058

https://www.elesa.com/siteassets/pdf/pdf_it/sm..pdf

mating them (for example to a nut m16) we have noticed (spannometrically) that there is much game; verifying and measuring more precisely the outer diameter of the stem m16 we find a value of 15,6 mm and we are trying to understand, tables of the baldassini to the hand, if this measure is acceptable or not.

we have speculated that the thread is in tolerance class 6g (average quality, "easy screw current applications, with galvanic protection").

is it correct to use the formula for calculating limit diameters (baldassini, chapter tables, iso threads with triangular profile, table 6)?
dmax = dnom - (es/1000)
dmin = dnom - ((es+td)/1000)

according to the above, we come out (if we did not wrong) a dmin of 15,682, so the pieces would be out of tolerance.

What do you think?
Thank you.

if you have a micrometer with inserts, 60° female plate and 60° male conical tip, the measure you detect is the average diameter, which in your case must be 14,7mm.

 

[meccanicamg]

if you have a micrometer with inserts, 60° female plate and 60° male conical tip, the measure you detect is the average diameter, which in your case must be 14,7mm.

micrometer with tip and coats is a rare object in the 2000s.
the system with the three calibrated cylinders is more functional.
for large diameter, just think that you can turn with cnc the three measuring rods and use a good caliber, where the error of the cent.... but also two is influential. thinks that the same thing is used to measure gears to straight teeth.
However if you dance so much the error you see it also with the three rollers and a normal caliber....without uncomfortable (the appropriate specific equipment) and understand whether or not there is error.
then if in the meantime you lend the proper equipment you can improve reading.

 

[Sleepers]

if you have a micrometer with inserts, 60° female plate and 60° male conical tip, the measure you detect is the average diameter, which in your case must be 14,7mm.

ah, it is true, the micrometer for fillets with the conical tip on one side and the caprug on the other!
I forgot, I think I've never seen one live, just books or pictures.

I take advantage of it to update you: in the end, while having an appreciable game, the feet do not give problems, so the direction decided not to contest them.