METRIC TAP ON INCH DRAWING

For the following examples, where INCHES is the default dimensions for
a drawing, which METRIC TAP call-out is correct according to ANSI/ISO
standards, or your company practice?

You'll have to pretend that @ is the proper diameter symbol, and -> is
the depth symbol...

A) inch dims with metric thread

2X @ .276 -> .827
M8x1.0 - 6H -> .630

B) metric dims with metric thread (with brackets designating mm)

2X @ [7] -> [21]
M8x1.0 - 6H -> [16]

C) dual dimensions

2X @ .276[7] -> .827[21]
M8x1.0 - 6H -> .630[16]

D) none of the above ;-)

Any advice would be appreciated.

Thanks,

-JOSH

 

I just do "A". Just show the metric tap with the depth and drill in
inch. All you are doing is calling out the spec for a tool, and that
tool just so happens to be called M8x1.0 instead of 5/16-18 UNC.

(Just a side comment: unless there is a need to control the thread
beyond what is normal, don't bother calling out the drill size and
depth; just callout the tap and its depth. Let the vendor work out
what's best for them. In theory, this will save you a little $ ->
fewer specifications = less cost.)

 

Josh,

I do "A", but I delete the tap drill data and change the units to
fractional. This is what my manufacturing guys like. So, it says
"M8x1.25 - 6H -> 5/8".

When manufacturing's happy, everyone's happy.

Reaper.

 

Well, CAM guys might disagree with that fractional statement.