gd&t (geometric dimensioning & tolerancing)

  1. E

    Question on GD&T added to print - Positional callout for the small holes

    Hi all! We have received a print that GD&T callouts were added to and I'm not sure I agree/understand some of the callouts. In the drawing below - is the B datum just the one hole? And how would you measure the 0.2 positional tolerance back to itself? If the B datum is only the one hole...
  2. D

    GD&T Drawing Question - I have a drawing and it makes no sense to me whatsoever

    I have a drawing and it makes no sense to me whatsoever. There is an A datum, "bottom" surface, as you would expect. There is a rectangular slot that is shown as Basic, while the OD of the part has a positional callout back to datum A (only). Then there is a four-bolt hole pattern, but each...
  3. Marc

    RFS - Regardless of Feature Size (GD&T)

    REGARDLESS OF FEATURE SIZE (RFS) Regardless of Feature Size (RFS): RFS is the default modifier. so if there is no modifier symbol shown in feature control frame, it means RFS is the default modifier. RFS is used when the size feature does not affect the specified tolerance. Source: GD&T...
  4. B

    True Position Measurement

    Hi all, I'm fairly new to GD& T and trying to wrap my head around measuring position tolerances. I understand how to measure the tolerance if given an x,y dimension but how would I check the position callout highlighted on this print clip? A is a threaded hole but for the sake of simplicity...
  5. Roberticus

    Negative corner radius (per ISO 1101)?

    Good afternoon all. Hoping to get a bit of help understanding a callout on a print. Don't really comprehend per my GD&T exposure. Corner/edge callout, not tied to any detail or section of the overall part. Specified as a negative 0.1. Used to a minimum edge radius but not a negative value...
  6. M

    GD&T tolerance or band? Using a symbol like parallelism //

    Its been a while since I've used my GD&T knowledge When using a symbol like parallelism // the numbers next to it in the box is that a band or a tolerance. Say its stated as .125 inside the box, is that +/- .125 or is that a band of .125 or a tolerance of +/- .0625? Thanks in advance,
  7. P

    True Position vs X and Y Dimensions

    Hello All, This is my first post on Elsmar so please bare with me. I am measuring a part using my Romer Arm and Polyworks. The problem I am getting is the the X dimension is in tolerance (Basic), the Y dimension is in tolerance (Basic), but then the true position is 14mm out of tolerance. I...
  8. D

    Drawing (print) does not specify restrained or free state

    My company primarily makes engine gaskets and I'm new to the GD&T and interpreting drawings and blueprints. However, I was looking at a blue print of a muffler gasket and noticed there was no indication of whether the measurements were taken in a free state or constrained state. If it does not...
  9. O

    Gage Simulator for a Pilot at RFS

    Hello Guys, I have two question regarding a GD&T. 1. I have this drawing (attached) that has two pilots but one of them has an orientation tolerance at RFS (Regardless of Feature Size). I have very clear how to build a Gage for inspecting this if that would be at MMC, but at RFS I just remember...
  10. N

    Dimensional Inspection - Symbology cheat sheet

    Hello all - I've been a free agent for a couple of months, and Tuesday 20180501 I'm interviewing with a nearby machine shop for an inspection position. I've been inactive in that area for long enough that if I'm hired it will be because they like me, not because of my knowledge. I'll get...
  11. rmf180

    Reporting Profile of a surface with U modifier

    Current and new customer have begun specifying profile of a surface using the U modifier as detailed in the latest version of ANSI y14.5. I have had numerous conversations over the years regarding the intent of profile is bet illustrated as attribute but customers insist on variable data. As...
  12. E

    Best GD&T training - Your suggestions and recommendations please

    Hello All,:bigwave: I am in search of GD&T training. I just want to ensure that I get quality training, does not matter the format; online, webinar, print, etc. Does anyone have any suggestions? Thanks in advance. :D
  13. M

    Best Practice for setting tolerances on a Drawing

    I looked through the forum and couldn't find the information I was looking for, so hopefully the forum can help me out. I'm looking for information to help guide my engineering department toward a better way to control and standardize our drawings. Specifically tolerances. They seem to...
  14. B

    Counterbore - Hole or feature?

    I have a drawing that the block tolerances for a .XXX "feature" is +/- .005" and the block tolerance for a .XXX "hole" is +.003/-.001. Which is the correct tolerance to use for a counterbore, feature or hole? Thanks.
  15. O

    Orientation with respect to a Compound Datum

    Hello guys. I have a question about a lower segment of position tolerancing controlling orientation with respect to a compound datum. attached is a ppt that help you to better understand my question. Thanks in advance, Regards.\.
  16. O

    What does "Gap" and "Flush" in ASME Y14.5 mean?

    Hello Guys, I have seen a lot of times the terms "GAP and FLUSH" in GD&T drawings, but I have been looking for that terminology in the ASME Y14.5 Standard and I have not found anything. Do you know what is the meaning of these two terms? Thanks in advance, Regards.
  17. O

    Thread Diameter as a Datum

    Hello guys. I have a question of how to threat a thread diameter called out as a Datum. Attached is a portion of the drawing in question. This part has 4 extremities with threaded nuts called out as a Datum . 4 of them are primary Datum. rest of them are secondary. bottom line here is that...
  18. T

    Establishing -F- datum - need advice

    Having some disagreements on how to establish this -F- datum on a machining print. The circle through the hole is determined by the location of two other boltholes on this casting. Question is: Two lines on the outside of boss (cast surface) establish a center point between them and place it on...
  19. M

    True Position / GD&T - I'm staring at this drawing and I'm lost

    Hi, I'm in desperate need of help regarding true position. I included a picture that i drew to help (attached below). I apologize for the lack of quality and i did my best with confidentiality restrictions. Ok, so here it goes, I was thrown into a project at work and I barely have any...
  20. B

    Profile of a Surface Callout on this Drawing

    Please settle this dispute with this profile of surface callout, Someone out there will know the exact interpretation. See enclosed jpeg. I am saying we have a +/-.0005 tolerance band for all surfaces in this view, unilateral, Because of the all around symbol. Anyone see this any differently?
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