Punkinhead
Cast Iron
- Joined
- Feb 13, 2010
- Location
- IN, USA
We're switching to metric for all drawings. We design one off machines, so no production runs or large quantities. 6061 or al jig plate are our most common materials and pretty much every detail we design will be smaller than 400mm and most are below 100mm. All machining is done by outside suppliers. We've always used the number of digits after the decimal for default tolerancing of inch drawings but with metric we'll drop trailing zeroes. So what would you prefer to see as a general tolerance note in the title block for machined parts? Which would you rather see, "Unspecified tolerances follow ISO 2768-fH" or across the board tolerances like "Unspecified tolerances +/- 0.13 mm, +/- 0.25 degrees for angles"? The latter ends up being tighter than ISO 2768 as parts grow but keeps the machinist from having to reference a separate document.
Thoughts?
Thoughts?