Grinding wheel selection?
How to select a grinding wheel?
Short, general answer. Depends on many variables.
The most basic in general:
*The harder the steel (material), the softer the wheel.
*The more stock to remove, the coarser the wheel.
*The finer finish required, the finer the grit.
*The sharper internal corner desired, the harder and finer the wheel to do just the corner.
To go much beyond that, you would need to be specific as to material, machine, etc. etc.
One thing to keep in mind. A grinding wheel is basically thousands of little cutters the same as other machine tool cutters. Many of the same rules apply to both.
Wheel for 52100
What's the best, or your favorite wheel for grinding hard (65 RC) 52100?
For grinding D2, a blue SG wheel is invaluable and will grind without burning or excessive wear like a standard aluminium oxide wheel.
I also found that grinding in my mag chuck with an SG wheel left it considerably cooler than using an Alox wheel.
Is that SG as in Seeded Gel?
I do believe that's what he means. Seeded gel aluminum oxide..
Originally Posted by Mark Rand
I've got a challenge for you guys.
I need to surface grind some 6061T6 aluminum and 410 stainless assemblies such that a pocketed stainles insert must be flush with its aluminum housing, and all must be flat to 0.0003"/ft. I've talked to two different Norton folks and got different answers, and neither made me feel very confident in their recomendations. There is about twice the amount of stainless to grind than aluminum. What do you think??
Probably not a problem... BUT need more info... Overall size and config. How ya gonna hold it. Wet or dry, type of machine, finish required?. One off or looking for production. Any additional info would be good too.
You shouldn't have any trouble with the 410 but the aluminum will give you heartburn. It will want to collect in your wheel and eventually fly off in chunks and even take some or all of your wheel with it as well as leave ugly scars in your workpiece. One way to alleviate this condition is with liberal doses of beeswax to the periphery of the wheel. Beeswax used to be available in stick form from many industrial suppliers. Can't tell you if it still is. Keep applying it as you grind. It wants to melt as it gets heated. If you don't have variable speed use a small diameter wheel. Less heat is generated. I'm assuming you're dry grinding. Don't know much about wet grinding. If you're wet grinding, straight honing oil might be better than mixed coolant. Thats a guess.
Originally Posted by VSMI
it's great to have a separate grinding forum. I've done some plain Jane surface grinding and been around some pretty good mold makers/grinder hands but have never picked up a very good knowledge base.
In the home shop, I have a Boyar-Schultz 6x12. I do all my grinding dry. So The first question: what is a good all-around wheel for softer steels: unhardened O-1, 4140 PH, and cold-rolled? Secondly, like VSMI I also have a project that calls for grinding 6061 aluminum so I'm also looking for tips/wheel selection advice on that.
Lurk mode off....
Novice question here, but the selection of wheel is said to be determined by (among
other things) the hardness of the steel being ground.
So to be sure I'm getting the concept, the idea is that one would choose a
different wheel for steel that is not heat treated, such as ordinary cold rolled
steel, or leaded steel, and then a different wheel when the steel is high carbon steel
that has been heat treated - and that further the wheel grade might be
further influenced by the rockwell number of the steel being worked on.
Is this a fair approximation of the idea?
Lurk mode on....
Yes it is Jim... refer to post #1 of this thread
I like Winterthur wheels in the OD Grinding area. We use a 53A and cuts 416ss and 4340 very well. This wheel will cut 17-4ph @H900 and does just okay on 303ss.
ID grinding wheel we like Cincinnati Wheels that are a Ruby/Aluminum Oxide. They cut 304ss pretty good. The parts still gets warm but it does better than any others we have tried.
Centerless Grinding Wheels, I like two different wheels 22A Cincinnati Wheels and WZ100 Jowitt Rodger. The Jowitt is a Resin type wheel and it works great on thin walled tubing.
Now for SG wheels from Norton, I really don't like the wheels for anything but Surface grinding. A ceramic wheel takes to much wheel pressure to make a cut correctly. That is why it works well on surface grinding but you can't put a lot of wheel pressure in a OD or Id application.
I love this forum.. So much to learn. I never heard of Winturthur. My grinding has been limited to surface grinders for such a long time...
Also never ground 300 series ss...
Winterthur is from Austria. They are excellent wheels and of coarse you pay for it also.
Here is a webpage that has a lot of different cataloges that might be of some interest. http://www.rappold-winterthur.com/en...catalogues.php
300 series stainless is not all the same. 303ss grinds very well but when you get to 304-316ss I believe they have a higher nickel or something like that in them and it does not grind very good at all. The parts will heat up and if it is long and thin then they will bend or if it is a tube they will go out of round.
Yep, thats the one. Mine is a 46IV, bought from Abtec http://www.abtecindustries.com/ who also sell on e-bay UK.
Originally Posted by Mark Rand
I'm by no means a grinding expert, I did the grinding module as part of my apprenticeship many years ago then moved out of hands-on machining for 25 years till I took it up again as a hobby.
Most of my grinding in the past few years has been on a manual 'Eagle' surface grinder from Dronsfield. That has now been sold and replaced with a J&S 540 that I have yet to install.
I have ground a fair amount of non ferrous material (aluminum, bronze) and use a silicon carbide wheel from Norton (37C black stone variety) with liberal amounts of WD40 as a cutting fluid but never when it was married to a dissimiliar metal but I would try it if it were mine.
I need to surface grind some 6061T6 aluminum and 410 stainless assemblies such that a pocketed stainles insert must be flush with its aluminum housing, and all must be flat to 0.0003"/ft. I've talked to two different Norton folks and got different answers, and neither made me feel very confident in their recomendations. There is about twice the amount of stainless to grind than aluminum. What do you think?? 05-06-2008 12:00 AM
Also for selecting types of wheels, when i grind core pins on the surface grinder i plunge grind and, i find the shorter the contact area the harder the wheel needs to be , even if its 50 RC, i use 60k whenever i have less than .25 of the wheel tounching. leaves a nice sharp corner. this is a 1" thick wheel. for most steel i find 46I will do just about everything. I'll bump up to a 60 to hold a better corner. Has anyone tried those red wheels from norton? any advantage over the 32A high performance AO?
I have a coarse silicon carbide wheel and a 220 grit white alum. oxide wheel on my pedestal grinder. Contrary to what I have read, the silicon carbe wheel cuts much cooler than the alum. oxide, doesn't wear down, doesn't burn tools. There must be other variables that I need to take into account...
I am grinding the side of a grove in a-2 rc maybe 55. Any suggestions on how to contour the side of the wheel and what grit and hardness to use
Dress your wheel like this. Use a hand held dressing stick.
Edit:Assuming a surface grinder, use a 32A60-I8vbe. Some operators like to grind from the top of the slot down as in plunge grinding. I like to side wheel the entire slot as in feeding with the cross feed. It's an art form to get the desired geometry.