Replies

1. 
   HowardAcheson | Oct 26, 2002 11:00pm | #1

   As a reference plane for other measurement. Toolmakers use them all the time. In the tool and mold company I ran we had 15 - 20 of them and they required semi-annual certification as to their flatness. The higher the precision of flatness, the more expensive.

   I really question the price quoted for the Harbor Freight plate. Ours costed much, much more even for small ones.

1. 
   DWRead | Oct 27, 2002 12:31am | #2

   Thanks, Howie. I was wondering about the $20 myself. Perhaps they are available in a range of tolerances. You wouldn't need a high-end plate for sharpening tools, would you?

1. 
   JeffKurtz | Oct 27, 2002 12:36am | #3

   Grizzly has them for reasonable prices.  I like mine a lot better than using a piece of glass.

   Jeff

1. 
   DP | Oct 27, 2002 07:24pm | #4

   Lee Valley has one for $29.95.  It's guaranteed to +/- 0.00001".

1. 
   UncleDunc | Oct 27, 2002 11:22pm | #5

   The Lee Valley web site says 0.0001" and $42.50

   http://www.leevalley.com/wood/page.asp?SID=&ccurrency=1&page=32526&category=1%2C43513

   Another thing to keep in mind on one these cheap surface plates is that if you can't pick it up at the store, the shipping charge is likely to be pretty breathtaking.

   But I have to agree that they make nice sharpening plates. I got a 12 x 18 x 3 for my metalworking shop and so far I've used it more for sanding than I have for metalworking.

   Edited 10/27/2002 5:38:39 PM ET by Uncle Dunc

2. 
   DP | Oct 28, 2002 04:42pm | #8

   My mistake on the tolerance; I typed one too many 0's.    Both the current Lee Valley 2002/2003 catalog and their website list the plate (catalog number 88N85.01) at $29.95 US.  Shipping was $7.00.  Your price was in Canadian currency. 

3. 
   jgaiennie | Jan 24, 2003 05:17pm | #10

   Unc et al,

   let's see...

   1 / 10,000th in 12".  That's as flat as we need as woodworkers, isn't it?  Or maybe flatter!

   What in the world are you guys doing with these flat surfaces?  How can you possibly need that level of flatness? 

   What am I missing here?

   jdg

4. 
   UncleDunc | Jan 24, 2003 07:19pm | #11

   jdg - In the woodworking context, I use it for sharpening chisels and plane irons with sandpaper. Yes, it's probably overkill, but at the prices that were given earlier in this thread, it's not much more expensive than a stout piece of glass if you can't find a piece of scrap and have to buy some.

   Janet - I won't speak for Jeff, but for me the advantage of the granite is that you don't have to do anything in particular to keep it from sliding around on the bench.

2. 
   DWRead | Jan 24, 2003 02:04am | #9

   Jeff, how is granite better than glass?

   Janet

1. 
   JeffKurtz | Jan 24, 2003 08:13pm | #12

   I prefer granite for three reasons:

   It's much less fragile than glass so it's less likely to break.

   The substantial weight makes it very unlikely that it will fall off the bench.

   I like having one surface in the shop that I know is perfectly flat.

   Jeff

2. 
   RickL750 | Jan 24, 2003 08:25pm | #13

   What about Marble. I have a friend that uses a piece as his flat surface for sharpening. I personaly use a $7.00 piece of glass.

   RickL

2. 
   DaveHeinlein | Oct 28, 2002 01:14am | #6

   I got my granite plate as a cut off from a kitchen counter. It measures 6"x25". It is definetly flat enough for sharpening woodworking tools. Check out your local stone yard, you may get one free.

1. 
   Azeddie | Oct 28, 2002 04:23pm | #7

   I got one from MSC for about 35 bucks weighs about 85lbs...UGH, hurt my back moving from front door to garage, still in box , nowhere to put it. I do not want to be lifting it ...geeez

   makinsawdust