Glass as surface plate

Topics include, Machine Tools & Tooling, Precision Measuring, Materials and their Properties, Electrical discussions related to machine tools, setups, fixtures and jigs and other general discussion related to amateur machining.

Moderators: Harold_V, websterz, GlennW

Post Reply
Posts: 28
Joined: Tue Feb 10, 2009 8:24 pm
Location: Maine, USA

Glass as surface plate

Post by gbick » Thu Feb 02, 2012 6:30 pm

Given my current space and dollar constraints, I plan to get a piece of glass to use as a surface plate into the foreseeable future. I realize this won't be inspection quality, but should suffice for now. As I haven't yet bought it, I thought I would seek your collective advice. Thicker is better?? Tempered glass will probably stand up better to my frequent clumsyness, unless it is not the flattest type?? Please advise. Thanks. Greg.

Posts: 231
Joined: Tue Mar 23, 2010 9:38 pm
Location: SoCal

Re: Glass as surface plate

Post by pacrat » Thu Feb 02, 2012 7:38 pm

Might check local yellow pages for shop that does hard surface kitchen counters.

They will usually have a few sink cutouts of granite or marble they sell cheap. Last I bought was $20.

Still not inspection quality but a lot safer and tougher than glass. :wink:

Posts: 409
Joined: Wed May 24, 2006 8:40 am
Location: Canandaigua, NY

Re: Glass as surface plate

Post by Conrad_R_Hoffman » Thu Feb 02, 2012 7:54 pm

I've done this and the problem is it scratches and gouges way easier than you'd think. Even very heavy plate glass can easily flex by an eighth of an inch, depending on how you support it. The import surface plates, 12x16 or so, are really cheap and I've had one of those for years now.

1947 Logan 211 Lathe, Grizzly G1006 mill/drill, Clausing DP,
Boyar-Schultz 612H surface grinder, Sunnen hone, import
bandsaw, lots of measurement stuff, cutters, clutter & stuff.

"May the root sum of the squares of the Forces be with you."

Posts: 422
Joined: Fri Jan 22, 2010 12:55 am
Location: Missouri

Re: Glass as surface plate

Post by JTiers » Thu Feb 02, 2012 10:27 pm

Do you want FLAT? No foolin, really FLAT?

If you DO, but you want to use glass, or tombstones or countertop, none of which is made to BE flat, just nice-looking.........Then HOW LUCKY DO YOU FEEL TODAY?

'nuff said.

User avatar
Posts: 6974
Joined: Mon Jun 27, 2005 6:18 pm
Location: Connecticut

Re: Glass as surface plate

Post by SteveM » Thu Feb 02, 2012 11:38 pm

Enco has a 9x12 black granite plate for $42. Order $8 more stuff and find a "free shipping with $50 order" code and you won't pay for shipping.

Even better, the 12x18 is on sale for $45: ... TPG=INLMK3

Might want to check if there is a weight limit on the free shipping code. That one weights 85 pounds.

I have the 9x12. If I had more bench space, I'd get the 12x18.

How much money are you going to spend on a piece of glass that you are probably going to get rid of anyway in favor of a real surface plate?


Posts: 17849
Joined: Fri Dec 20, 2002 11:02 pm
Location: Onalaska, WA USA

Re: Glass as surface plate

Post by Harold_V » Fri Feb 03, 2012 1:07 am

If you must use a piece of glass, make it float glass, and NOT tempered. The tempering process can yield out of flat material. The thicker, the better, by the way.

Wise people talk because they have something to say. Fools talk because they have to say something.

Posts: 1545
Joined: Wed Mar 17, 2010 7:58 am
Location: Muskoka

Re: Glass as surface plate

Post by Torch » Fri Feb 03, 2012 7:44 am

I too am quite limited for space, and the 12"x18" surface plate weighs a fair bit to be hauling in and out as needed. So I built a plywood enclosure with handles and a removable top. If I really need to move it out of the way, the handles come into play -- or at least, that was the plan. I can't recall ever needing to move it because the removable top that protects it does double duty as temporary bench space any time the plate is not in use.

Here's how it looked when I built it:
and here's how it looks today:

Posts: 1065
Joined: Mon Jun 11, 2007 10:49 pm
Location: Northern New Jersey, USA

Re: Glass as surface plate

Post by PeteH » Fri Feb 03, 2012 11:55 am

Current Enco "Hot Deals" lists the 12x18 Class B plate for $45.95 -- and at least when I bought mine, two years ago, the "free shipping" code applied (check recent postings in this forum for the current code).

They CAN'T have made money on that one !!

BTW, if you don't need the thing instantly, it pays to check for better prices. IIRC, I didn't pay any more than that for their Class A. (Since the things aren't NIST traceable anyway, I don't know how much that matters... but I wanted the ledges -- 'tain't easy to haul an 80-pound plate around if you can't get a grip on it.)
Pete in NJ

Posts: 13
Joined: Fri Jun 12, 2009 11:43 am
Location: Northwood,NH

Re: Glass as surface plate

Post by farrviewsouth » Fri Feb 03, 2012 6:01 pm

Just got my 12 by 18 plate today from Enco, Yes $45 price did include free shipping UPS
with the free shipping code listed above. Thanks for the original tip and I don't see
how that price can be beat for my use :D

Post Reply