standard metric tolerance in title block?

[LuisAlberto]

I am in the process of adding the standard tolerance for metric parts in the sheet format. The company I work for does not have a standard tolerances for metric in thier current sheet format. I don't want to add tolerances to every dimension. Can anyone help me? Thanks

LuisAlberto

 

[gearguru]

You can use ISO tolerance description, like
js10 (JS10)
These tolerances are nominal size dependent, it means that
10mm js10 has smaller tolerance than 100mm js10.
You would have to educate a lot of people if you want to go this way.
More about the ISO tolerances / fits is in Machinery's Handbook.
gearguru

 

[looslib]

Standard tolerances can be added to the titleblock the sane as english dimensions are. The restriction comes if you say your drawing meets the requirements of ASME Y14.5m. This says that you cannot use trailing zeros to hold decimal places which would change the tolerances.



"Wildfires are dangerous, hard to control, and economically catastrophic."

Ben Loosli
CAD/CAM System Analyst
Ingersoll-Rand

 

[LuisAlberto]

I do want to use ANSI Y14.5 for adding the tolerance in the title block. How do I solve the problem on the trailing zeros to hold the tolerances? Is there another option but staying with ANSI standards? Thanks for the answers.

Luis Rivera

 

[GDTGUY]

One solution might be to invoke ANSI B4.3-1978 (R1999), "General Tolerances for Metric Dimensioned Products" rather than specifying tolerances in the title block. ANSI B4.3 shows how to specify the general tolerances for metric dimensions without a tolerance designation.

You could replace the existing block tolerance data in the title block with a statement such as "SEE ANSI B4.3 FOR GENERAL TOLERANCES" or simply "X" out the existing tolerance data and send the user to B4.3 via a general drawing note.

GDTGUY

 

[GDTGUY]

OOPS!!!

I need to retract the second part of my last posting.

You do not invoke ANSI B4.3 on the drawing!!! ANSI B4.3 simply provides options for specifying the tolerance on the drawing for metric dimensions. (I got my standards crossed up and was thinking of ANSI B4.2 Preferred Metric Limits and Fits!!!!..........sorry!)

Take a look at the options shown in ANSI B4.3. One of them will probably meet your needs.

GDTGUY

 

[LuisAlberto]

Thank you for your answers. I will look into ANSI B4.3 and see what is suitable for us. Thank you again.