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hwingo
02-28-2015, 11:39 AM
Good Morning Guys,

I am wanting to buy a slotting saw and arbor. I have never owned one much less used one. I will likely buy one from ENCO. I will likely use the slotting saw to make narrow cuts in aluminum (1/4") or steel (1/4" plate). Naturally I will most likely use it later for projects on bored out steel or aluminum round stock. I am leaning toward HSS.

1. If I had a choice of course teeth or fine teeth which should I choose?

2. Is it better to get a 2" dia slotting saw or something larger? I really can't see myself slotting something as deep as 1" or 1.5".

3. Which arbor is a better choice, the short arbor or the extended (long) arbor?

4. What thickness blade is overall best to have in the shop and why?

5. What is the recommended RPM for the slotting saw?

6. Basically, there seems to be two styles; normal looking circular saw or the other having long flutes extending toward the center of the saw. Which is best and why?

Would greatly appreciate you thoughts on the above 6 questions.


Thanks,
Harold

Toolguy
02-28-2015, 12:27 PM
My opinions, worth what you paid for them.

1. Fine teeth.

2. 2" with 1/2" shank will do most things.

3. A 2" long arbor will get most projects.

4. Standard sizes like 1/32, 1/16, 1/8, etc.

5. Around 100 rpm.

6. The flat ones work fine with plenty of lube. I like the side cutting ones better, but they have to be fairly thick for that.

There are lots of exceptions, depending on the job at hand. Often times I use the 3 wing carbide tipped cutters for woodworking on aluminum, you can spin those up pretty fast.

Rosco-P
02-28-2015, 01:07 PM
McMasterCarr has some info: http://www.mcmaster.com/#slitting-saws/=w3wdxm

J Tiers
02-28-2015, 01:16 PM
RPM cannot be specified without knowing diameter..... because what you WANT to know is really the "SFM", the feet per minute that the tooth is moving at. For instance, you want around 70 to 100 SFM for HSS and "mild steel". For a 3" saw, the circumference is about 10", roughly... so 100 rpm would be in-range. For a 2" saw, it would be slow, that is only around 6" circumference, and so you could go faster.

In tougher material, you may want less SFM, maybe 40 to 50 for tool steel, and you would want to go slower

Diameter is good, because it gets your arbor out of the way of clamps etc. I would not go under 3" to 4", just because at least 1" diameter is eaten up by many arbors, and another 5/8" to 1" RADIUS by clamps and studs. At that point you are about out of room for any cutting.

That's with a regular horizontal mill, with a full length arbor. For a BP and right angle head , you might do better.

There are regular saws, and there are slotting saws....

Regular ones look like a circular saw. You use those on deep slots at your peril, they jam up and cause trouble.

A slotting saw has cutting edges on the sides, is thicker, and will cut to as deep as the teeth reach.

Carm
02-28-2015, 01:39 PM
Mr. Wingo, do you have a lathe? If so, make your own arbor, for the specific bore of the saw. I suggest a low profile cap to increase clearance, you will soon find out that everything seems to get in the way.
As Jerry Tiers said, definitive answers are hard to give. I agree about larger diameters being better, and the SFM notes.

Just my own observations:

If shallow depth slitting/slotting is your job, the hollow ground blades work OK.
Generally, less teeth in the work the better as the gullets pack, the saw gets hot and things go south.
Any blade that cuts its own clearance is to be desired, either the "having long flutes extending toward the center of the saw" or teeth wider than the body. Nothing is ever perfect and there are demons lurking in the woods.

At the least, rig for air blast or mister if you don't flood.

Don't make a long arbor until you get some miles under your belt, minimize leverage.

garyhlucas
02-28-2015, 01:56 PM
This is a cold saw type operation. When sawing a chip rolls up in the gullet of each tooth. If the gullet isn't large enough to contain the chip then the chip may weld back to the base metal as it is dragged along and could break the blade. You always want at least two teeth in contact with the work at any time. Less and the material can go between the teeth and break them off. So as long as you have at least two teeth you won't have that problem. The more teeth engaging the work the more torque required to cut as each tooth requires a certain amount of power and it adds up. A fine blade with lots of teeth in contact may take too much torque. So you back off the feed rate to compensate and the chip becomes very thin and the metal work hardens quickly dulling the teeth. So a coarser blade with at least two teeth in contact is the better choice in most cases.

hwingo
02-28-2015, 02:09 PM
Hi Guys,

Your replies have been very helpful. Thanks so much for sharing your information. Following your suggestions closely, I just ordered a Straight Tooth Slitting Saw and a standard Weldon Arbor from Enco. The cutter is 4" dia with a 1" dia hole. I purchased an arbor to fit the saw and it's on its way.

Once again, MANY THANKS for your responses.

Harold

PStechPaul
02-28-2015, 04:04 PM
I picked up this assortment of 3" slitting and slotting saws at the Cabin Fever Expo last April, for about $15:

http://enginuitysystems.com/pix/tools/Slitting_Saws_0879_800p.jpg

The type with teeth on the side are also called side milling cutters. I also bought this probably home shop made arbor for a few dollars. I had to turn the shank down so it would fit in a Weldon mill holder:

http://enginuitysystems.com/pix/tools/Slitting_Saw_0876_800p.jpg

http://enginuitysystems.com/pix/tools/Slitting_Saw_0873_800p.jpg

I set it up to use in my lathe:

http://enginuitysystems.com/pix/tools/Slitting_Saw_0880_800p.jpg

I was able to make a small slot this way, but there is no way to adjust the vertical position without a milling attachment for the toolpost. As I tried to make another cut, the saw jammed and I broke the drive belt of the lathe. Here is a video showing the first cut and the second one with the "OOPS" moment:


https://www.youtube.com/watch?v=ebMLzRB1UgY

It is very important to make sure you do conventional milling and not climb milling when using a saw.

Black_Moons
02-28-2015, 04:24 PM
The bigger the diameter of the cutter, the more flex it will have and more chance it will wander in the cut

The longer the arbor, the more flex it will have and more chance it will chatter or worse.

Slitting saws are known to explode when they jam in the cut. Recommended *NOT* to use a key on your arbor, as having them spin on the arbor is preferred to exploding. You don't need the key to help drive them, just tighten the arbor nut well.