Grinding wheel

[Noitoen]

I have 2 cheap bench grinders, one with the original 150x20 mm wheels and the other with a wheel/belt grinder combination. I was thinking of installing a green silicon carbide wheel on this one for tool sharpening purposes.
My question. Is this stone "ok" for hss tool and drill sharpening? Is 100 grit good or should I use other? I thought they would be more expensive but have a quotation for 20,00€ for this size wheel. The sander has a 686x50 mm. belt, can this be used for sharpening as well?

 

[jack620]

Green SC wheels are used for sharpening carbide. I use white AlOx wheels for HSS. I use 60 and 100 grit. The 100 grit leaves a pretty good finish.

 

[Noitoen]

What I really need to know is if SC too good for HSS or inadequate.

 

[Swifty]

Green silicon carbide wheels break down rapidly to provide new sharp grits for grinding carbide. Grinding other metals with these wheels will break them down in no time. The best thing for HSS is aluminium oxide, white wheels, I feel that 60 grit would be fine, a good compromise. Some of the finer grits may burn the tool bit too easily, although this depends on the grade of bond used in the wheel.

Paul.

 

[Wizard69]

I have 2 cheap bench grinders, one with the original 150x20 mm wheels and the other with a wheel/belt grinder combination. I was thinking of installing a green silicon carbide wheel on this one for tool sharpening purposes.
My question. Is this stone "ok" for hss tool and drill sharpening? Is 100 grit good or should I use other? I thought they would be more expensive but have a quotation for 20,00€ for this size wheel. The sander has a 686x50 mm. belt, can this be used for sharpening as well?

I've sharpened tooling on green wheels that come with my HF "Baldor" style tool grinder. In some case HSS and in others carbon steel. The carbon steel in this case woodworking tools. Don't expect miracles from the course wheels as you will need to do a lot of touch up afterwards. I like my HSS tools sharp and at best these wheels can be seen as roughers. Generally most manufactures counter indicate such wheels for steel.

Honestly I'd recommend that you get a wheel or two specifically for HSS. One should be course and another fine. Six inch grinders can be a problem but the ripoff prices charged be some for grinding wheels could justify a bigger grinder. Here is an example pricing from Travers: http://www.travers.com/skulist.asp?...ls&q=block+id+38317+and+class+level3+id+30015. That is listed as a surface grinding wheel but it gives you an idea of wheel costs.

In the long run building or buying a tool grinder should be considered. Choose the right design and you will have an endless supply of wheels. If not a tool grinder consider a disc grinder already suggested. In fact your belt grinder might be usable for tool grinding. When it comes right down to it bench grinders are less than ideal for quality sharpening jobs. In my estimation this is why there are so many attempts at fixtures for bench grinders with the goal being to get a less than ideal machine to do the work required.

Beyond all of the above I like to put a finish edge on my cutting tools by honing. Even in metal work, with High Speed tool steels, this can impact the tools ability to cut.

 

[Wizard69]

Paul you point out an important point, wheels come in different grades. It is wheel worth it for individuals to reference manufactures information when selecting wheels. Even white wheels can vary dramatically in how they perform.

As too wheel grits, I prefer to mount a course wheel and then a finer one. Since most bench grinders take two wheels this is pretty easy to do. The "fine" wheel can and only should be used for final cleanup. That is final grinding before any honing is done.

Green silicon carbide wheels break down rapidly to provide new sharp grits for grinding carbide. Grinding other metals with these wheels will break them down in no time. The best thing for HSS is aluminium oxide, white wheels, I feel that 60 grit would be fine, a good compromise. Some of the finer grits may burn the tool bit too easily, although this depends on the grade of bond used in the wheel.

Paul.

 

[ZipSnipe]

Guess it depends if your sharpening carbide or not?

I prefer diamond wheels for carbide, I know they are expensive but damn its instant sharpening!!

I used to work at a Tool and Die shop and we had a grinder set up with a standard and green wheel, nobody used the green wheel, it was either the standard or go over to the diamond wheel.

Another note, the green wheels just feel like your sharpening the tool with a wheel of wax