huangyhg

.086-56 unc or 2-56 unc
i had a previous customer that required tapped holes be called out with the decimal major diameter(.086)instead of the screw number (2). i haven't found an asme specification that supports this. does anyone know if there is such a specification?
check out our whitepaper library.
asme b1.1-1989 unified inch screw threads, uses both.
thanks for the quick response.
asme y14.6-2001, screw thread representation, in section 3.2, specifically 3.2.1.3, details how they should be called out on drawings.
numbered sizes mayfff"> be shown because of established practices. the decimal equivalent, to three decimal places, shouldfff"> be shown in parentheses.
so you can show decimal without numbers, but if showing numbers you should show decimals too.
kenat,
thanks kenat,
i attempted to look at asme y14.6 but our .pdf file is only accessible to the person/computer that downloaded it. as soon as i track down that "person" i'll look it up.
gotta love 'smart' pdf's.
it's ok and common practice to only use the number, such as 2-58.
matt lorono
cad engineer/ecn analyst
silicon valley, ca
it may be common practice but the relevant asme standard does say you should add the decimal equivalent in parentheses. many people ignore that, like they ignore that it says to explicitly reference asme b1.1 or other thread form spec.
do so at your own risk and don't blame me in the unlikely event someone uses it as an excuse to make you buy a non functioning piece of ****.
there was a thread on here not so long ago where someone was confused thinking the # was the diameter in inches or something like that. to me that makes the case for following the standard and making it clear.
kenat,
i agree with kenat - it may be common practice, but that doesn't make it correct per the standard. if your company standard defines it differently, then fine. if you default to the asme standards, it is wrong.
good to know you got shoes to wear when you find the floor."fff"> - robert hunter

we all know what "should" and "may" means in the asme though.
matt lorono
cad engineer/ecn analyst
silicon valley, ca
from my experience, use 2-56 unc. the machinists understand this better. if you call out the decimal equiv, inspection may question tolerances.
either way you choose that works for your company, be consistant and stay with one type.
chris
solidworks 09, catia v5

__________________
借用达朗贝尔的名言：前进吧，你会得到信心!
[url="http://www.dimcax.com"]几何尺寸与公差标准[/url]