Cast Iron Box Surface Plate

[guitar286]

Can these be bought or are the specially made? I can only find 2 manufactures, Challenge and Busch, who still make CI surface plates. Traditional style surface plates that is.

[sidecar580]

What size are you looking for?
JOHN

[guitar286]

24x24 and maybe some smaller ones

[Forrest Addy]

What do you call a "box" surface plate? I'm a little mystified. Several supply houses offer square cast iron rough sections (4" x 4" and 4" x 8" by a foot or so long usually having a 3/4" wall IIRC). There are also tool maker's knees.

Look in Moore's "Foundations of Mechanical Accuracy." It has several examples including a master boxed square recently duplicated by someone. Anyone recall?

[guitar286]

"master boxed square"

I think thats the one. Has two flat sides, one being scraped and the other not. Its symmetric across the mid-plane of the cross section. They are more rigid than the traditional style which are unsymmetric. The ones Moore Tools uses are 48" square I think. Im not talking about the bench top plates which are typically around 10x14 and dont require 3 point support.

[beege]

Go to www.thomasnet.com, search for "Cast Iron Surface Plates" and see what you come up with. You can even refine the search to be local to you.

[guitar286]

Its not a right angle instrument like a toolmakers knee. Its simply a more rigid surface plate.

[SouthBendModel34]

G286:

"I can only find 2 manufactures, Challenge and Busch, who still make CI surface plates."

Do you have any web URL's for these mfr's ? I'm sure I'm not the only one curious about this. If your ThomasNet search turns up anything interesting, please include that too. Thanks much.

John Ruth

[gbent]

I have a Challenge made version of what you are looking for, I think. It is 18 x 24, 6 inches thick. It is cored out on the bottom side to leave a wall thickness of about 7/8" minimum. There are internal ribs, one in each direction. The longitudinal rib is full height, and finished at the same plane as the rest of the bottom. The cross rib is rebated about 1/4 inch. On the manufacturers label, type is stamped layout.

I don't know what the purpose of this plate is over a traditional surface plate, other than perhaps it is supported to the very edge. It is about 3 times heavier than a 18 x 24 cast iron surface plate. I would estimate the weight at over 300#. It was produced with a planed surface, never scraped.

Just based on material cost, I would expect a raw casting to cost in the $600-$1,000 range before machining. Granite looks pretty good.

[sidecar580]

I have a couple of 18 X 24 cast iron surface plates that can be had for $75.00 each........... shipping may be a prob....they are heavy
JOHN

[precisionworks]

http://www.challengeprecision.com/ma...nds/lobby3.htm

http://www.buschprecision.com/surface_plates.html

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Barry Milton

[guitar286]

John:

www.challengeprecision.com
www.buschprecision.com

Seems odd you guys would have non square versions of these seeing as getting rid of the inevitable warp is nearly impossible with the 3 plate method. Here is a simple image of what im talking about.