Questions about a Casting Drawings
Questions about a Casting Drawings
(OP)
A call-out note for two holes on a casting drawing say:
Φ.468 Drill
Φ.500 Reground E.M.
Φ0.5025 Reamer
2XΦ.5025+/-0.010 THRU
questions:
1. what's E.M. represent?
2. Reground is supposed to have a higher accuracy than "Reamer", why is the "reground" before "Reamer"?
3. Is "Reground" same as "ground"? why "RE-"?
thanks!
Φ.468 Drill
Φ.500 Reground E.M.
Φ0.5025 Reamer
2XΦ.5025+/-0.010 THRU
questions:
1. what's E.M. represent?
2. Reground is supposed to have a higher accuracy than "Reamer", why is the "reground" before "Reamer"?
3. Is "Reground" same as "ground"? why "RE-"?
thanks!





RE: Questions about a Casting Drawings
Chris
SolidWorks 10 SP4.0
ctopher's home
SolidWorks Legion
RE: Questions about a Casting Drawings
So arguably the important part is the final dimension 2XΦ.5025+/-0.010 THRU.
I suppose if the EM means Electron_beam_machining then maybe it imparts properties to the material which are significant.
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Questions about a Casting Drawings
E.M = End Mill
Reground means they want to make sure the End Mill is sharp and to size.
We do this process a lot on holes that have a tight location tolerance.
1. Center Drill hole
2. Undersize Drill hole
3. Use EM in a drill cycle and bore down, say .2 deep
(This squares up and fine tune locates the hole for the reamer. A basic peck drill cycle can wonder off center, and a reamer would follow that, so the EM drill cycle brings it back to center.)
4. Ream hole
RE: Questions about a Casting Drawings
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Questions about a Casting Drawings
RE: Questions about a Casting Drawings
Why not just .500 +/- 0.008?
Center drill, drill 3/8, drill 31/64, drill 1/2 should do it unless there is a requirement for a specific finish.
RE: Questions about a Casting Drawings