Specifying GD&T on a Hex machined nut
Specifying GD&T on a Hex machined nut
(OP)
Hello, I am trying to define GD&T on machined hole inside a Hex shape.
Nut is forged and then machined. Inside machined hole has to with in .005" of outer Hex shape.
thank you !
Nut is forged and then machined. Inside machined hole has to with in .005" of outer Hex shape.
thank you !





RE: Specifying GD&T on a Hex machined nut
Regards,
Cory
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: Specifying GD&T on a Hex machined nut
Not enough information.
What are you trying to accomplish?
JHG
RE: Specifying GD&T on a Hex machined nut
Question: Are you using the forged hex as is, or is it too being machined?
One way might be to clamp the hex in V's as an equalizing datum, ASME Y14.5-1994 Figure 4-38 (page 78)as is often done with castings. It then becomes a B-C datum for locating the internal hole positioned with respect to Datums A and B-C.
RE: Specifying GD&T on a Hex machined nut
The word "nut" is used, implying an internal thread. The thread is the datum for fasteners, with other dimensions referring to it.
Regards,
Cory
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: Specifying GD&T on a Hex machined nut
RE: Specifying GD&T on a Hex machined nut
-Nut is forged in hex shape, and forged hex shape is not machined after.
-based on these hex flats, threaded hole in the center need to be machined.
CheckerRon, you are right I want to use the forged hex as a datum to locate the internal hole. Also I did check the fig.4-38 in ASME Y14.5M-1994, but did not understand much...
CoryPad, It is 28mm threaded forged nut. Each nut is forged and internal hole and thread and chamfer is machined. I beleive our supplier is machining it on Milling machine, because of that hole is accentric. To control that I have to specify the tolerance.
I am still not clear how will the datum be defined with the outer hex.
RE: Specifying GD&T on a Hex machined nut
I believe my reference is the exact one you need to measure your part for an accurate relationship between threaded hole and outer hexagon.
Regards,
Cory
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: Specifying GD&T on a Hex machined nut
RE: Specifying GD&T on a Hex machined nut
RE: Specifying GD&T on a Hex machined nut
I believe the purpose of Y14.5 is to define the method for defining and inspecting the required accuracy of the part definition. Accuracy is another thing.
RE: Specifying GD&T on a Hex machined nut
1 a: to determine or identify the essential qualities or meaning of <whatever defines us as human> b: to discover and set forth the meaning of (as a word) c: to create on a computer <define a window> <define a procedure>
2 a: to fix or mark the limits of : demarcate <rigidly defined property lines> b: to make distinct, clear, or detailed especially in outline <the issues aren't too well defined>
If the fabricator does not have the part definition, how do you expect him to make the part? Accuracy is an essential element of the definition.
RE: Specifying GD&T on a Hex machined nut
RE: Specifying GD&T on a Hex machined nut