# Granite surface plate



## precisionworks (Mar 13, 2009)

I was poking around the Enco site and found a great deal on a granite plate. 18x24x3" thick, two ledges, Grade B, $59.95. 

Enco free shipping code for March, 2009, is *PRSMAR*, and does not apply to this plate because the shipping weight is 225#, so it goes by truck. Even if you don't need the plate, the free shipping applies to any order over $25 that can go UPS (under 80#).


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## precisionworks (Mar 13, 2009)

Their smaller plate will ship free ... it is 12x18x3" thick, two ledges, inspection Grade A (the next better grade). $36.95, part number 640-0422. Use the same PRSMAR code at checkout to get the free shipping - it worked just now for me.

Not a bad deal to get an 80# plate shipped at no charge


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## StrikerDown (Mar 13, 2009)

precisionworks said:


> Their smaller plate will ship free ... it is 12x18x3" thick, two ledges, inspection Grade A (the next better grade). $36.95, part number 640-0422. Use the same PRSMAR code at checkout to get the free shipping - it worked just now for me.
> 
> Not a bad deal to get an 80# plate shipped at no charge



I picked up a 12 x 18 a while back with the free shipping... It's almost the same as pay the shipping for a free plate 

Enco must get great discounts for their shipping volume.

Thanks for the update Barry. It's time to get out the catalog lovecpf


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## wquiles (Mar 13, 2009)

+1

I picked one (the smaller Grade A) with free shipping. Nice bargain indeed 

Will


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## precisionworks (Mar 13, 2009)

The best thing about that plate are the ledges. Not only do they provide two clamping surfaces, they also provide two very nice handles for moving the plate around the bench. Cast iron plates are another thing to consider, as mag bases & mag V-blocks will stick to the surface. Most cast iron plates have ledges on all four sides, where less expensive granite plates have ledges on the two shorter sides.

My iron plate came from Craigslist, but there are always a bunch on eBay.


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## SafetyBob (Mar 14, 2009)

I do like the ledges, I found that the "little" 12 x 18 we all got last month? was plenty, plenty heavy. 

Just for the record, I was looking through that Enco sales flyer, most everything was at least 40% off with a strong amount of them 50% also. If you have the cash, it is a very, very good time to stock up on some stuff. 

Going to go through the flyer this weekend and see how much I can afford to get. I need a tap here, some drills there.......Broke again....

Bob E.


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## PEU (Mar 14, 2009)

Where is globalization when one needs it...  I always drool at these bargains you guys enjoy...


Pablo


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## precisionworks (Mar 31, 2009)

This seemed like a good place for the newest Enco free shipping code:

Free shipping on any order over $25






Promo code *WEBPA9*

Expires Sept 30, 2009, at 2300 EDT


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## precisionworks (Apr 3, 2009)

The Starrett surface gage will hold the stem of an Interapid dial test indicator, which is nice for set up work or height measurement.

Using a pair of Starrett "snugs" allows adding a second arm for a dial indicator.


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## darkzero (Apr 4, 2009)

Excuse me for my lack of knowledge but what are granite surface plates used for? Trying to figure out if I need one or not. :laughing:


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## precisionworks (Apr 4, 2009)

> what are granite surface plates used for?


Surface plates, whether granite or cast iron, are a very stable & exceedingly flat reference surface. A height gage is used on a flat & will indicate the same zero datum point anywhere on the surface, so odd shaped parts or large parts (that can't be measured in a mic or caliper) are easily gaged on the surface plate.

Plates are also handy for marking out or laying out a part before machining. Coat the part with Dykem, set it on the plate, and use a surface gage (or height gage with carbide scriber) to mark layout lines at a precise height above the plate.

If you have a center finder attachment for the height gage, it's easy to pick up exact hole centers on a part that you're trying to duplicate.

Granite plates seem smoother (to me) than a cast iron plate. The cast iron plate is nice because it has clamping ledges on all four sides, and magnet bases stick to it (look at the upper right side of my last photo, and you'll see a Brown & Sharpe mag V-block, which is really handy for inspecting round parts).

As Starrett says, don't use the bigger plates for a lunch table

http://www.starrett.com/pages/860_granite_surface_plates.cfm


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## gadget_lover (Apr 4, 2009)

They are accurately ground slabs of rock that are ( I think) dimensionally stable. As far as I know, they don't warp. 

You use it as a reference surface when you want to layout lines on a part or when you want to map the surface of a part. It's how you verify that your 10 x 2 inch x 3 inch long block of stuff (tm) is really that dimension.

Daniel


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