want to understand about geomatrical tolerence feature

[fsa]

hello every one i have a problem about understanding the (geomatrical tolerence feature) actually i have a drawing for manufacturing the componant and i know that it is not a difficult to make this part.(see the image for details)but mhen i read the geomatrical tolerence note i feel that manufaturing of this part is not very easy.i want to give some prove to my client that those features on a part is make according to the specfic giving geomatrical tolernece and all features within the tolerence range ,need some advise also reference documents for understanding the tolerences specially geomatericall tolerence ples see image

[NC Cams]

They are trying to hold the positioning and depths of the designated holes in relative positions with respect to features/surfaces A (the flange surface) and B (the ID of the bore).

This position is being held rather tightly (within a diameter of 0.1). Yes, the part is relatively EASY to make, UNTIL/UNLESS you have to meet and understand the GDT call outs. This is where the part goes from being a simple tube fitting to a VERY PRECISELY machined and toleranced piece of JEWELRY.

Don't agree or even START to make this item until/unless your production AND your inspection/QC dept understand the GDT specs COMPLETELY and the ramifications of compliance/non-compliance.

A basic manual on GD&T should explain the call outs to/for you. You may need to have someone show you what these REALLY mean - the specs are NOT necessarily self evident. I have seen situations where those untrained in GD&T "read" the specs and totally misinterpret them.

Sometimes, there are even cases where the designer "says" something with the GD&T specs but really means somethinge else. Thus, you sometimes have to ask the client "what do you need/want with respect to this tolerance". Sadly, designers sometimes "overspec" the drawing because the available GD&T tolerances are all that they know but may NOT be truly/properly controlling what they're trying to do.

Asking for "clerification" on a message board my not be your best/better method of determining what your client is asking you to make.....

[mrainey]

You might find some good info here:

http://www.tec-ease.com/gdt-tips.htm

[fsa]

thanks for your replys about my post and for good references.

[dpuch]

From mrainey's response you'll get better info, but a VERY simple explination of the hole tolerance is your hole center has a .1mm diamater target relative to -A- (the center bore)

This might be compared to a +- 0.05 box target if it was not GD&T and they asked for +-0.05mm on the hole positions. Considering other GD&T requirements it is probably closer to trying to do +-0.035 hole location tolerances.

NC Cams points are very valid about understanding GD&T before biding.

Dale