A tolerancing question

[gcode]

we have a flatness callout labeled .005/1X1 can someone tell me what the 1X1 means?

[Joe788]

How large is the surface? I've seen similar callouts that were flatness per distance/area, but they're usually for much tighter tolerance.

 

.005 max flatness on a 1x1 inch area is pretty generous.

[gcode]

How large is the surface? I've seen similar callouts that were flatness per distance/area, but they're usually for much tighter tolerance.

 

.005 max flatness on a 1x1 inch area is pretty generous.

 

not very big .. its a 1/4" wide strip running aroung the perimetr of the lid to a fancy aerospace box

[Brad St.]

was it called out in GDT? is it related to a datum at all? Are the prints related or called to any ANSI spec's or does the customer have custom callouts?

 

sorry more questions to your questions tom =), but i'd agree it would look to be an area specification for the tolerance.

[specv]

We see that all the time, it is flatness in a 1x1 square, normally on thin parts that will be constrained in assembly and the overall flatness does not matter much.

[heavychevy2155]

I was always told to "Make it like the print". I would always say, I would if I knew what all this crap meant. They would really give me some nasty looks. Ah the good old days.

[Rotary Ninja]

It's funny some of the things you see on prints. I remember when I started out in Aerospace and we would get prints from GE. There would be 30 pages with balloon views referencing balloon views off of section views spread across 10 pages of aft looking forward, forward looking aft, and sideways looking up the engineer's ahhh.... let's not go there. Don't even get me started on Mil-Spec callouts, especially for threaded inserts. I had to keep a drawer of my toolbox set aside for all the paperwork. Then when you get the part all done some 80 year old inspector checks it with a tape measure LOL.