Best design practice : Representing circular hole pattern in a drawing

[baliasM74U3]

Hi Experts

INV 2020

What is the best way/practice of representing a circular hole pattern in a drawing ?

[Chancellor.Kurre]

It depends on your manufacturing method. If these parts are drilled on a lathe with a dividing head I would dimension differently than if they were being cut on a laser. What is the method of manufacture?

[CGBenner]

@baliasM74U3  For flanges we always dimensioned using a Bolt Circle diameter, from the center point of the pattern to the center of the circles.  Then along with the BC diameter, we'd include a note stating how many holes at what size, and the spacing.  Example:  ø3/8" DRILL THRU, 16 HOLES EQUALY SPACED ON ø12" B.C.  

[johnsonshiue]

Hi! If I understood the requirement correctly, patterned center mark might be what you were looking for.

https://knowledge.autodesk.com/support/inventor/learn-explore/caas/CloudHelp/cloudhelp/2019/ENU/Inve...

Many thanks!