granite surface plates?

[wquiles]

Many times I need something nice and flat to measure and compare parts, so given the free shipping offers from Enco and others, I am starting to consider a granite surface plate. Any opinions/suggestions/alternatives?

Will

 

[karlthev]

Yes. Go to a contractor who specializes in countertops and get a good-sized hunk of the scrap. Attach four of the adhesive-backed "feet" to the bottom and you will have an (virtually!) indestructible flat surface that'll look great. Watch out for oil though unless you seal it well--even granite will absorb oil and stain. I used to use such a setup years ago working leather.


Karl

 

[Fred S]

Consider a surface ground piece of regular ol A 36 plate, way cheaper. Have the plate normalized before grinding, it will be within .001 if you are careful with the grinding

 

[Mick]

Every machinist worth his/her salt should have a "Pet Rock" Mine is 12 x 18 x 3 and helps reduce vibrations in my work bench. LOL

 

[gadget_lover]

I have a small 12x16 plate, it was a cheap purchase from enco.

If you are doing someting that really requires accuracy, then you need a really accurate plate. A countertop is not necessarily going to be accurate in any dimension.

Most of the time mine sits on a shelf under my bench. I almost never need that much accuracy.

Dan

 

[just for fun]

You might want to watch Craigs list if you not in a hurry. I picked a pair of great steel surface plates up for 50.00 each. Lynn

 

[will]

also consider plate glass - very flat, but breakable

 

[donn_]

See if you can find a chunk of Silestone. I bought one from the guy who made my shower bench and enclosure capstone. The stuff is nearly impervious to everything, and very cool looking.

 

[griff]

Talk to Griff..he has one for trade:naughty:

 

[precisionworks]

Interesting reading: http://www.qualitydigest.com/aug03/articles/03_article.shtml

Small granite plates are dirt cheap, about $25 for a 12x18, flat to +/- .0002 (Grade B). You can do a lot of work on a plate that size. The only problem with these plates is that they have no clamping ledge, and there are many times that you'll want to clamp an indicator in position. You can purchase plates with either 2 or 4 clamping ledges:

2-ledge plate

4-ledge plate

Another good option is a cast iron plate. Ledges are cast into the plate, but mine are mostly used with magnetic bases. My Challenge Precision 12x18 lists for $569, but $50 brought it home from a Craigslist ad.

If you have room or funds for only one, buy a granite flat with at least two ledges. Then try to find a cast iron plate on eBay or Craigslist.

 

[wquiles]

Thank you guys. Right now I can get a 12" x 18" x 3", Inspection Grade A, with 2 ledges, for $36.95 and FREE shipping (80 pounds!) from Enco. This sounds like a great size for my work bench and a real good buy for the money

Will

 

[LukeA]

Thank you guys. Right now I can get a 12" x 18" x 3", Inspection Grade A, with 2 ledges, for $36.95 and FREE shipping (80 pounds!) from Enco. This sounds like a great size for my work bench and a real good buy for the money

Will

How are you getting the free shipping?

 

[precisionworks]

Enco has a free shipping code every month ($50 minimum order to qualify). This month, you enter promo code WBJ9R on the shopping cart page before you click checkout.

Next month, Google February 2009 Enco free shipping, and you'll have the new code. They've been doing this forever, but don't advertise it too heavily.

 

[wquiles]

Enco has a free shipping code every month ($50 minimum order to qualify). This month, you enter promo code WBJ9R on the shopping cart page before you click checkout.

Next month, Google February 2009 Enco free shipping, and you'll have the new code. They've been doing this forever, but don't advertise it too heavily.

Yup, same code I am using for my granite plate

Will

 

[LukeA]

Thanks! That surface plate is too good a deal to pass up.

 

[Fred S]

Boy at those kind of prices, you probably shouldnt even consider anything else

 

[SafetyBob]

HOLLY CRAP. Incase any of you want to know. Right now if you go to enco, that 12 x 18 inch plate with two ledges and grade A was $79.07....now it is $36.95.

Get one now, before I get the last one........why wouldn't I get one....someone tell me.

Bob E.

 

[SafetyBob]

OK, to late, I got my Grade A, 12 x 18 inch, 2 ledge plate with at gallon of Vectra 2 way oil that I should have got about 10 years ago so happy days are here!!!!

Bob E.

I should have gotten the 18 x 24 Grade B but I didn't know if I could move it/lift around alot. I would have to go to the gym awhile......I don't want to do that right now.

 

[precisionworks]

I should have gotten the 18 x 24 Grade B but I didn't know if I could move it

Unless you work on lots of large parts, the 12x18 should be perfect. As the weight of anything approaches or exceeds 100#, it can be a real pain to move.

There are a couple of tools that are really handy for surface plate work. Height gages let the part rest on the plate, giving you both hands to work with. Digital gages are the rage today, which makes manual gages a super buy. Always a bunch on eBay ... my 18" Brown & Sharpe Etalon cost $50 with fitted case.

A surface gage performs many functions on a granite flat. Attach a dial indicator, zero the indicator using a stack of gage blocks, and quickly check parts as they come off the lathe, mill, or surface grinder:

Install the scriber, set your part on the granite flat, and slide the surface gage to mark a line within .001":

Again, no batteries & no digital display mean that these are cheap on eBay, even if you get the Starrett 257 (on the right) with hardened base & four pins.

Starrett also makes a neat base, the No.62 rule holder, for surface plate use (and it will usually hold a Mitu or B&S rule):

 

[SafetyBob]

As always, great pictures with examples AND part numbers to look for on eBAy!!!!!

Thanks,

Bob E.