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Why do 6x48 belt sanders/grinders for metal seem uncommon?

As a woodwoorker, this is interesting, as I occasionally grind hss pattern knives for my shaper. 5/16" or 3/8" thick, 1" to 3" wide. Can be a lot of steel to remove, been cutting as close as I can with an abrasive cut-off saw, then to the grinder.

Questions: would one of these belt sanders be a lot faster than an 8", 3/4 hp, 3500 rpm bench grinder? Is it just a horsepower thing? What kind of belt would be best to hog material off?

There is no comparison to any bench grinder I have used. It may be that the necessity of using a binder that is strong enough to prevent a wheel exploding limits wheel makers significantly. I am using 3M cubitron 60 grit as my general purpose weld prep and shaping belt though I have a good selection of specialized belts for other purposes. Anyway, if you look at my vid above of grinding 1X1x1/8" steel angle i was not even working the grinder hard and the angle just disappears. If I were using a 36 grit, the rate would be significantly greater. But, the 60 seems like a nice compromise.

I think if you were contouring your cutters, you would benefit from a belt grinder that has the small contact wheel attachment similar to the one shown above. Some of those attachments do not have the idler wheel which wraps the belt tightly around the contact wheel, thus limiting access to recesses if that is a factor in your work.

I do a modest amount of wood work with mine as it is quite handy for pattern making. Using it horizontally with the tilt table allows easy cutting of draft into outside flat surfaces in a very controlled way not to mention fitting parts etc.

The extra horsepower is very nice, but I have been told that high SFM is easier on belts when grinding steel. So, suspect the high SFM is a factor as well. I have followed that advice and belts last a long long time.

Here is what a close-up of the swarf looks like---more strands than dust.

And this is what a "mat" of the swarf looks like suspended from my fingers:
Swarf Mat.jpg

I still regret not buying this monster, but it was the biggest floor space hog ever!



jack vines
What you are saying concerning a platen and square table has merit as the majority of the time a belt grinder will be used to grind squarish faces on metal. But, there are also plenty of occasions where an angled face is needed and it is particularly helpful if a table can be set to that angle. And not always are the surfaces needing grinding flat surfaces. These needs to my suggestion to not get a simple 3-wheel (with fixed table) design. The design I suggested above includes provision for changing out belts AND tables and platen for contact wheel and small contact wheel attachments in seconds. The spring-loaded silver lever in the photos above is a combo tracking and tensioning lever that allows changing belts in less than 30 seconds. I made the recommended fixed 90 deg trable and the variable angle table, flat platten, slightly arched platen, large contact wheel and small contact wheel attachments. In a lot of commercial and shop-fabricated grinders exchanging these features is cumbersome and time-consuming (read that as not likely to be done unless there is a big need), but in this design exchanging them is quick and painless. And switching from vertical to horizontal mode which is especially useful for long parts takes 15 seconds with no change in table height needed.

I don't use the small contact wheel attachment often in my shop. But when I need it it does work that no othere grinder in the shop can do. Same for the curved platen---not often neeeded but nice when you want it.

Here is the small contact attachment that accepts "wheels" down to 1/2" diameter.

My apologies if I'm beating the drum to hard on this.


That looks like an incredible setup, very versatile as you said. Impressive balance test and I love the cart.

I haven't looked extensively at the offerings from the likes of Burr King; is this design quite a bit more flexible?
Thanks all for sharing your experience and advice, lot of great thoughts. I'm relieved that others like large tables and platens as I have come to; and those versatile narrow belts setups look very enticing.

So here's what I brought home this weekend: it's an Engelberg/Sundstrand B3 with a 5hp 3ph motor, 10 x 70 1/2 belt, huge platen and 10x20" table.

Belt speed is a little slower than I wanted, at around 3800 sfpm; hopefully the HP makes up for it with removing material. I'm thinking to add a VFD down the road for variable speed--anybody know if I can spin that motor much faster than the 1740 rpm stamped on the plate? I need to do all the VFD research.

It's wider than my belt/disc combo, but not by as much as I first assumed; and I may build a stand over the motor for my bench grinder to maximize the footprint.

Those narrow belt setups look very useful, and maybe someday I will have one. For now, looks like I'm doubling down on the big belt and table arrangement... It just makes sense to me, since I'm usually trying to flatten larger parts and not so much sharpening tools or making knives. (On that note, when somebody says "I love my ____ and use it 99% of the time even though I also have that other thing you're considering," I have trouble weighing that opinion without having any idea what kind of work they're doing with said tool.)


I have a 4x36" belt sander from 1920 (est).
It has tight and loose pulleys.
Made in England. All cast iron.
It does not have a tracking adjustment.
Just crowned rollers.
Never had an issue.
Yes it surprises me too.
It is so old, I think it was made around
the time that 3M (Minnesota Mining &
Manufacturing) invented sanding belts.