Can I use surface grinding wheels foe the bench grinder?

I've just gotten a Baldor 7 inch grinder, 3600rpm, half horsepower. It had silicon carbide wheels on it, but ill be using this grinder exclusively for gridning high speed tools.
The only suitable wheels I can get that are designated to be for bench grinders are, CGW blue aluminum oxide, appare rlt designed to grind high speed steel. Id get 36 grit and 80 grinder, but the hardness for both is K.

From what I understand, K hardness is a bit hard for hand grinding, and I'd be looking for something in the I or J range.

If I look in the wheels for surface grinding, at a semi local shop, I have a mich higher selection of 7 inch wheels, but they have 1.5inch arbor holes.
I can make an adapter no problem, but can I use a surface grinding wheel on the bench grinder?
The grinder asks for 1 inch wide wheels, but typically the 1 inch wide surface grinding wheels have a recess on one side.

Will any of these features make it unsafe to operate the surface grinding wheel in a bench grinder, given that I make an appropriate bore adapter and it is run below the rate rpm?

I could imagine that the recession could be an issue, as when I grind hss, ill be using not the entire endface of the wheel simultaneously like in surface grinding, but I will be using either side of the wheels face, depending on what feature I am gridning into a peice of hss.

Thank you for reading and looking forward to the replies.

Frequently the hubs and clamp washers of bench grinders are less precise and robust than the mount hubs on surface grinders. I think that in general you'd be OK to use SG wheels for offhand use, but if you want to face grind I would contact the wheel manufacturer and get an applications person to give approval.

I've made more precise/larger clamping washers for bench grinders for my own use, even mounted a carbide grinder to a mill, squared it up with the spindle parallel to X, then used a lathe bit in a clamped flycutter to face the wheel mount while under power. This gives you as true-running a wheel as you're likely to get, but must be done carefully to avoid damage or injury.

Hi dzarren:
Pedestal grinder wheels are run differently from surface grinder wheels and what is considered to be a "hard" wheel for surface grinding is considered to be a "soft " wheel for bench grinding.
Bench grinder wheels are typically in the "O" to "R" hardness range, so that they can tolerate heavy and uneven grinding pressure without breaking down too fast.
A typical surface grinder wheel of "J" hardness will erode super rapidly under those conditions, especially on the corners of the wheel.

For surface grinding, a "K" wheel is chosen to retain the form dressed into the periphery of the wheel when form grinding, but the pressure on the wheel is small and consistent...a heavy downfeed when plunge grinding on a surface grinder is 0.001" per pass and a more typical downfeed is in the 0.0001" to 0.0003" range with spring passes every few increments.

So yes, you can use a surface grinder wheel for bench grinding, but you cannot expect it to hold its shape very well, and it will make a fair mess.
What you gain for all that inconvenience, is that the wheel will always have lots of fresh sharp abrasive grains available to make chips with...they're so loosely held in the wheel that they are lost from the wheel surface before they get a chance to get dull.
A sharp abrasive grain cuts cool...there is less friction produced as it shears a chip, so a soft wheel will not burn the workpiece as readily, and will not distort the workpiece from retained heat as readily.
That's the primary reason surface grinder wheels are so soft...it's much easier to work precisely when the wheel cuts cool, but you get that at the expense of having to dress the wheel frequently.
Add flood coolant to the mix and you can grind so cool you can maintain precision in the micron range, and that's what surface grinding is all about.

Cheers

Marcus
Implant Mechanix • Design & Innovation > HOME
Vancouver Wire EDM -- Wire EDM Machining

I've got almost 50 years in, hand grinding profiles on woodworking moulding and shaper blades, as well as other tools including metal working. It's how it was done most places into the 50's, & many still until the late 70's.

Small surface grinder wheel hole size is 1.250"
Wider collars as someone else mentioned are not a bad thing.
I use vitrified 7" & 8" surface grinder wheels, 1" width down through 1/4" width. However, my offhand grinder is belt drive, and runs closer to 2800 rpm IIRC.

Experiment, but IMO, K is too hard for most stuff. It will seem even harder at 3600 rpm.
J is a little soft.
Wheels will consume faster on the pedestal, than on the surface grinder. Especially as the diameter/sfm recedes.
There's something of a trade-off - free, mostly cool cutting with perceptible wheel erosion. Or harder, more dressing, hotter, less erosion. It may be necessary to have one harder (K +) 60 grit wheel dressed for holding sharp corners. But that will be a very slow, hot wheel for routine stock removal.

I use almost exclusively 46 grit. Any hand ground tool should be honed to refine shape and put the optimum edge on it. So a bunch of good hand stones and slips. At least a hard, med or fine "gouge sharpening hone"/slip for most contours since it does ID & OD. Modern versions may need ground a bit on the OD side near the tip, to shape them rounder in that area. Handfuls of "files" (slips) in various grits in square, rectangle, and various size rounds and cones.

A diamond single point hand stick for dressing or shaping the wheel.

The only wheel i ever broke was as a teenager, when i tried to use an open wheel pedestal grinder as a rotary surface grinder.
It worked well for a few parts, then started to settle. I groveled on the floor trying to reach the plug to yank out when the 1/2" thick wheel exploded. 1/2 of it stuck in the wood shop ceiling and hung there like a crescent moon.

Do use good safety practice, guards, etc.
Get in the habit of ringing the wheels every time.

smt

All I've got to say on that subject is: if you do it and use a soft wheel, use dust collection. Or you will regret it. Wheel particles and dust will be everywhere if you have to do any heavy grinding. And you'll go through wheels like crazy. There's a reason that harder wheels are suggested for use on a bench grinder. I might suggest using a harder wheel for roughing-in/hogging and use the softer wheel for finish grinding and touch-ups.

I'd suggest that the main reason most bench.pedestal grinders have a very hard wheel is for use on soft/mild steel. Downside of that is that when it gets used to sharpen drills/lathe tools etc, or isn't dressed often eough, it gets so 'blunt' that it won't cut and just burns the metal. Most of the pedestal grinder wheels I ever saw at wotk were in this condition.

So:- Hard wheel on one side, usually 36 grit, for mild steel and dress it before the grains get rounded. Soft wheel (Mine's a 60 grit 8" K at 3000rpm, but that's very fine) on the other end for finishing work on HSS and hardened steel that doesn't need the surface grinder.

The 'hard' wheels will always be pedestal/bench grinder specific, the soft wheels are interchangable with surface grinder wheels of appropriate grades.

A lot of bench grinder work is rough snagging and a soft wheel would break down too fast to hold a flat edge/face.
A surface grinder wheel does well on a bench grinder, it just takes a little more care to keep it flat.

QT: [Will any of these features make it unsafe to operate the surface grinding wheel in a bench grinder],
As long as the RPM is correct for the wheel, blotters fit to the flanges and to the wheel, the spacer fits the shaft and to to the wheel.. and all wheels are ring tested ID SG wheel are safe. I would try to stick with as wide a wheel for general work. A narrow wheel like 1/4" wide would be safe only for grinding on the OD of the wheel (not on the side).

for hand grinding hss tools i use a 60 gritt j wheel, 200 mm 2800 rpm. i rarely need a better finish.