Hexagonal Callout on Drawing

[vc66]

Hello All -

First time post... I need to call out a hexagonal shaft on a drawing, but I'm not sure if there is a specific way to call it out (i.e. flat to flat, Ø of hex, etc.)

Any and all help is Appreciated.

Best Regards,

Victor

Mechanical Engineer/Consultant
Medical Devices
"When I am working on a problem, I do not think of beauty, but when I've finished, if the solution is not beautiful, I know it is wrong."

- R. Buckminster Fuller

 

[CoryPad]

Usually, you place dimensions on both "across flats" and "across corners" since dimensional variation means you cannot have a perfect hexagonal form ( inradius:circumradius ratio of [√]3:2).

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[ewh]

If it is not a tolerance critical part, I only dimension across the flats and add "HEX" after the dimension. A reference dimension across corners is good for stk ref.

 

[KENAT]

For a tolerance critical part I think I've usually seen 3X dimension across flats and 6X 60°.

I've also seen dimension across flats with HEX after it like ewh.

Rarely if ever have I seen it dimensioned to the corners or the equivalent diameter.

Interestingly I don't see a single example of a hex or other regular polygon in ASME Y14.5M, I only looked briefly though.

KENAT, probably the least qualified checker you'll ever meet...

 

[CoryPad]

The most common hexagons are for fasteners. Page 39-41 of the following document shows dimensions for across flats and across corners.

MIL-DTL-1222J STUDS, BOLTS, SCREWS AND NUTS FOR APPLICATIONS WHERE A HIGH DEGREE OF RELIABILITY IS REQUIRED; GENERAL SPECIFICATION FOR

available at ASSIST:

http://assist.daps.dla.mil/quicksearch/

This is standard in industry.

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.