For our shop I would label it as,
Ream .50 Dp
For 1/4 SF Dowel
2 Holes
In the case of a press fit I always drill a thru hole first so they can
knock it out with a punch, I would label that as,
3/16 Drill Thru & Ream .50 Dp
For 1/4 PF Dowel
2 Holes
We build special machines and they know the ream sizes. The only time I
spell out actual ream sizes is if I'm doing tooling that needs to be held to
tolerances that differ from standard.
I use the same structure for c-bored or c-sinked holes such as,
Drill Thru & C-Bore
For 1/4 S.H.C.S.
2 Holes
or
Drill Thru & C-Bore To Depth Shown
For 1/4 S.H.C.S.
2 Holes
For the case of non standard c-bore depths.
I also use spotface diameters in major weldments and label them as,
Drill Thru & Spotface .13 Dp
For 1/4 S.H.C.S.
2 Holes
Note: This labeling practice does not lend itself to easy automation using
hole notes but I like to spell it out for the shop guys. That way they don't
have to interpret 3 numbers to realize I wand a standard 1/4 c-bored hole.
They are going to use a thru drill and a c-bore tool so I try to keep it
simple.
"Mark A. Bystry" wrote in message
news:3313504317DD8EBB2246452071E7A6AF@in.WebX.maYIadrTaRb...
> what's the correct callout for a 1/4" reamed hole 1/2" deep? we use asme
> y14.5 standards.
>
> --
> Mark A. Bystry
> Engineer
> Ziggity Systems, Inc.
> mbystry@ziggity,com
>
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