Extrusion Twist GD&T Specification
Extrusion Twist GD&T Specification
(OP)
Does anyone have a slick way of calling out twist on an extrusion? I can't find any GD&T standard to address twist. The twist I'm speaking of is a general roll of the material as it leaves the extrusion and is pulled through the rollers. Perhaps degrees/feet?





RE: Extrusion Twist GD&T Specification
There is no American standard for twist.
German DIN 1748 covers aluminum profiles and that's about it.
If significant area of your part should be flat in perfect "untwisted" state you may try to use Flatness.
There isn't much more to say given the information you provided.
RE: Extrusion Twist GD&T Specification
Do you want twist, or are you trying to eliminate it?
Flatness tolerances can be applied per-unit length if you wish. I do not know about profile tolerances. This would be worth looking up.
Your extruder will cut his extrusions into twenty foot pieces, right?
RE: Extrusion Twist GD&T Specification
Drstrole
GDTP - Senior Level
RE: Extrusion Twist GD&T Specification
I want to spell it out on the print but haven't been able to find the proper callout for twist.
I'll check out the Aluminum Extrusion Manual to see if that fits.
RE: Extrusion Twist GD&T Specification
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?