Replies

1. 
   UncleDunc | Dec 02, 2004 01:57pm | #1

   >> Would both 60 and 80 rate as medium?

   Yes. The 80 grit is obviously a little finer than the 60, but still pretty close to medium.

   >> Any idea why the Delta gray and white wheels would both be listed as 60 grit, medium?

   Because they are both made of 60 grit size abrasive grains. The main difference between the two is the bond strength. The white wheel has a softer bond. The grains break away easier, so the wheel is always presenting fresh, sharp cutting edges to the work, which results in less heat generation. The white wheels are designed for grinding tool steel, like woodworking tools. (Steel woodworking tools, not carbide.) The grey wheel has a harder bond which holds onto the grains longer, to maximize the amount of work done by each grain. It is designed for general grinding where heat generation is not as much of a concern.

   Here's a Google search that will lead you to a bunch of different sites with basic grinding wheel information.

   http://www.google.com/search?hl=en&lr=&ie=ISO-8859-1&safe=off&q=%22grinding+wheel%22+bond+grit

   
   

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   Edited 12/2/2004 5:58 am ET by Uncle Dunc

1. 
   notDusty | Dec 02, 2004 06:29pm | #2

                     Uncle ,

         That was a very complete and informative reply to a confusing area . I have always been under the impression that the lighter color the wheel the softer and least amount of heat will be generated during grinding . We are lucky to have your helpful sharing of a wide base of knowledge .

                   thanks                dusty

2. 
   larrmartin | Dec 12, 2004 01:11am | #3

   Thanks for the clarification. I now remember reading that color had nothing to do with grit size but did reflect bonding. And I definitely have much better luck with avoiding overheating when using the white wheel.