【转帖】olerance block crossout - per what std

yang686526

tolerance block "crossout" - per what std?
our company has always crossed out (big "x" from corner to corner) the tolerance block on our std sheet formats whenever it didn't apply to the drawing.  for example, if it's a control drawing of a washer, we will specify a size of  0.094"id x 0.250"od x 0.032"thk. those are parameters that purchasing uses to order the right size, but i don't want inspection to be checking the washer dimensions within .005.  so, we cross out the tol block to indicate that it does not apply.
this practice is now being chalanged by our new director of qa!!!
does anyone know what standard this comes from?
chris wilson
cad administrator
cswp
i have only ever crossed out the tolerance block when other tolerances were included in the notes or body of the drawing, or where all dimensions were reference.
good to know you got shoes to wear when you find the floor."fff"> - robert hunter

but do you know if there is an ansi/asme/iso standard that governs this practice?
chris wilson
cad administrator
cswp
no, i don't know of any standard which governs the use of untoleranced, non-reference dimensions, and doubt that one exists.  perhaps someone else here can point us to the applicable standard.
good to know you got shoes to wear when you find the floor."fff"> - robert hunter

if you don't put a tolerance, then you don't set a pass fail criteria.  as ewh says it's one thing to cross out the block and replace it, but what you are doing is virtually making the dimensions reference only.
similar came up a few weeks ago, regarding control drawings, where i believe it was determined they should have tolerances.
asme y14.24-1999 defines the requirements for control drawings so i'd look there, however, it doesn't go into much detail on the tolerancing issues.  your example sounds like maybe a procurement control drawing, section 8.1 for which the example given doesn't explicitly indicate whether or not the dimensions are toleranced.
kenat,
solidworksguru,
   why is your director of qa objecting to the crossed out block, and what does he want to do instead?
   you can apply dimensions to your washers as reference dimensions and leave the tolerance block intact, but i an not sure what this accomplishes.
               jhg
no need to cross out anything.  notes supersede the title block.  explicit tolerances supersede notes.
good point drawoh.  is the qa guy objecting specifically to crossing out the tol block, or is he objecting to the lack of pass/fail criteria?
kenat,
good point, tick.  the easiest solution would probably be to make all dimensions reference, or a note to that effect, and leave the tolerance block alone.
good to know you got shoes to wear when you find the floor."fff"> - robert hunter

the only place i can recall seeing the tolerance block alteration is in the global drawing requirements manual, 10th ed., section 5-23.  it allows a user to line through tolerances shown on the block and a flag is located within the box which refers back to the note section with different tolerances.
usually with a washer the dimensions go back to a certain standard.  this standard needs to be meet. what do you put on the drawing to make sure the dimension meet the standard?  do you put reference dimensions or do you replicate the dimensions that are on the standard with the appopriate tolerances?