Has anyone tried using the diamond masonary grinding wheels for grinding hardened blades, They would probably need to be driven at a slower speed and maybe cooled and lubed with water but I was waiting in an engineering supply place today for an order to be filled and was wondering around the shelves looking at random things and spotted them. They were 125mm dia and could be mounted on a spindle, a cup wheel would give a hollow grind if the the blade was presented to it correctly. What are your thoughts?

I hope your life insurance is paid up

Diamond doesn't work well on steel, cbn is what you would want if you decide to go ahead with it.

cbn = Cubic Boron Nitride if you didn't know.

The short answer is No.

The longer answer is that because metal and masonry behave differently under a cutting wheel, they need different kinds of abrasives and -- perhaps more importantly -- different matrices holding the abrasive together. Because masonry is very hard and brittle (unlike metal's ductility and malleability), it needs a combination of grit and matrix that allows for smooth cuts that don't shatter the edges where the blade exits the cut. Metal-cutting wheels, on the other hand, need to clear out the metal particles that would otherwise clog the wheel and cause it to cut poorly. 

3 hours ago, JHCC said:

The short answer is No.

 

Thanks for that clear answer, its what I thought it would be cheers

"Perfection is achieved, not when there is nothing more to add, but when there is nothing left to take away." -- Antoine de Saint-Exupéry

Although your question has been well answered, I would like to add that a "diamond wheel" can vary widely in construction and application, as also pointed out by JHCC.  For example, when grinding carbide brazed on tool steel, the diamond wheel must at times grind into the tool steel to maintain claerance geometries.  One would select a resin bonded wheel, typically, designed for 70% carbide and 30% tool steel contact.

On the other hand, CBN can be a lot of fun and satisfaction as it glides through carbon and high speed steels, durable, somewhat forgiving cool cutting dry, and holding their form well, when in a ridgid setup.

Robert Taylor