【转帖】metric dimensioning suffi

yang686526

metric dimensioning suffix
i have a metric dimension: 20.0 h6
now i remember back in sohool reading about all this stuff but i don't remember where the information is.
i need an explaination on these designations for both id and od, external and internal callouts.
can anybody help?
20.0 is the dimension and the h6 is the tolerance designation for that hole or shaft.
best regards,
heckler
sr. mechanical engineer
sw2007 sp 2.0 & pro/e 2001
dell precision 370
p4 3.6 ghz, 1gb ram
xp pro sp2.0
nvidia quadro fx 1400
      o
  _`\(,_
(_)/ (_)
never argue with an idiot. they'll bring you down to their level and beat you with experience every time.
here you go
if i'm reading my charts correctly:
hole - 20 ei=0 / es=8
shaft - 20 es=0 / ei=-4
best regards,
heckler
sr. mechanical engineer
sw2007 sp 2.0 & pro/e 2001
dell precision 370
p4 3.6 ghz, 1gb ram
xp pro sp2.0
nvidia quadro fx 1400
      o
  _`\(,_
(_)/ (_)
never argue with an idiot. they'll bring you down to their level and beat you with experience every time.
just throwing this one out there for fyi...
h6 is for housing fits (bore id's) +13/-0 for 20mm
h6 is for shaft fits (od's) +0/-13 for 20mm
edson gebo
mechanical designer/drafter
sw2007 sp2.0
cadra 2006 (yup 2d still exists)
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sometimes success begins at failure
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pwwest-
if you are going to be working much with limits and fits, you're probably going to want to buy the standard for the country you are working in and/or selling to.  besides the iso 286 standard you saw in the link in ajack1's post, in the us you will want to have ansi b4.1 and ansi b4.2 for english and si fits respectively.  in the uk you will want to get bs 4500.
i believe that no matter what you are doing, if there is a relevant standard it's best to have it at hand.
regards -john
bs 4500?? wow, i guess my zeuss "data charts and reference tables" are a little out of date then. they use the bs 1916c (august 1954) standard.
cor-
then you really don't want to reflect too long on the fact that the full designation is bs 4500:1969. :<}
regards -john
oh  ... just 15 years? that's not so bad then.  
   this is all described in the machinery's handbook.  my 26th edition quotes ansi b4.2-1978 (r1994).
                       jhg