best way to cut metal for a new guy

sunshadow said:
cutoff discs on angle grinders are meant for *cutting off*, taking a bar and making it shorter, they are not made for long shaping cuts profiling a blade
cutoff discs over 5 inches should be mounted in a cutoff saw and used for cutting off
trying to do shaping cuts with an 8 inch cutoff disc on an angle grinder is playing russian roulette with a hand grenade.
shape with a hammer, shape with a belt grinder, shape with a bandsaw, if you have to shape with an angle grinder, use it for grinding with a disc that is meant for grinding with that angle grinder

be safe
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I said the exact same thing to my boss at the steel fabrication plant I worked at; he told me to "shut up and get back to work" and I was a 19yr old kid so that's exactly what I did. What a jerk...
 
Like most machinery in the shop the angle grinder is only as safe as the operator.

I worry more about the buffer.:eek:
Fred
 
this is a lot of great advice.

i'm a bit scared of the angle grinder to be honest, I don't want the discs to break off and injure myself.

I ended up using the new dremel cutting discs that use the quick-latch attachment. they are more expensive than the normal wheels, but i ended up being able to cut through 1/4" 5160 slowly. the two cuts were about an inch and the blade didn't wear away at all, where the normal wheels wear quick.

i used a hacksaw to finish it off once it was almost done.

i have some longer cuts to make now. i might start with a light cutting with the dremel and finish with the hacksaw.

when people make knives, how much do they cut it to shape before they try to profile it on the belt sander platen? how much area should I leave outside of the lines I want the knife to have? Is 1/8" - 3/16" an acceptable amount to have to grind off with the belt sander? Or should I try to cut it closer?
 
i am very much a newbie, but i try to get as close to shape as possible before going to the grinder... course i only have a 1x30 grinder.

jake
 
I use a cut off disk on my angle grinder for cutting harder steels quite often. Just make sure to check the disk, keep it straight while cutting, and let it get to full speed before starting the cut. As these people have said, watch the sparks and safety glasses and ear protection is a necessity. You want to use safety glasses with side protection on them, else the steel particles could get around them. Some form of respirator is high ly recommended, this goes for with grinders as well.

As for gloves, the sparks usually don't bother me, but I have found out that gloves helps against the angle grinder's vibration. So as these people have said, gloves are highly recommended as well.
 
ya know after setting myself on fire as mentioned before a leather apron would be a good idea also

jake
 
this thread has alot of good safety advise. it should almost be in the newbies stickys
 
I use angle grinders exclusively, there are lots of attachments can be used with it. Here are some examples:
Those are flap discs, most are zircon sanders. It works great for removing the cutting marks from spine, bolster shaping etc..
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Wire brushes are the best thing to remove paint and thick dust:
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Diamond wheels, to cut tiles, concrete or bricks:
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To refine the profile of roughly cut steel I use these grinding wheels a lot:
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Buffing wheels and sponges are the most useful things to polish large areas, like your old car :). Don't use them for little objects, like blades ...
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Orbital sander discs and sandpapers were great find for me. Whole work at the workshop was speeded up. There are lots of grits around for these, I found from 40 to 400...
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Those are what I use mostly, but there are lots of different attachments, even there are wood cutter discs around, I wouldn't dare to use them though, looks really dangerous.

There are different kinds of cutoff discs. There is a normal iron cutter discs that are a bit thick. Those last very long time but it is a waste of quality steel when used to cut a blade profile. Try to use the "INOX" thin cutters. It cuts real quick and removes minimal steel. Those are delicate, just cut at 90 degree, never try to change the cutting angle..

One little advice, never push the angle grinder, let it work with its weight, no matter what attachment you use and never remove the guard. It is supposed to be there, you can place the guard and the handle to your liking. Be sure the guard is set to the handle side. It is also beneficial as a cutting guide, I place the guard edge on the steel and let the angle grinder do the job, if you are standing at the right side, A.G. walks by itself...
 
The only time I ever used an angle grinder and a cutting wheel without the guard I cut a little notch in the back of my thumb when my hand slipped and slid up the body of the grinder. Not something I would choose to repeat.

The only thing I can add about using a cutting disk on an angle grinder is that it will cut any shape that can be made with straight lines. And once you start the cut, there's no bending the wheel to correct the cut line to one side or the other. Stay on the line you started on, or go back and re-start the cut. But bending a cutting wheel is a good way to make it break.

When you get to shaping, coarse grit flap disks are much faster at removing metal than vitreous bond grinding wheels (A27 wheels) but of course they do cost more and wear out faster. Speed always costs more
 
obsessis said:
when people make knives, how much do they cut it to shape before they try to profile it on the belt sander platen? how much area should I leave outside of the lines I want the knife to have? Is 1/8" - 3/16" an acceptable amount to have to grind off with the belt sander? Or should I try to cut it closer?
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Fire and Hammer. 90% plus to shape at the forge then grind off the scale and pits. Last 2 I did took less than 10 minutes to grind.
 
To use an angle grinder properly.

Cut straight lines near the edge, then profile with a grinding disc or flap disk. I like the flap disc but the grinding disk lasts longer and removes faster. Flap disk is a good place to finish the edge before fine work.
 
An angle grinder will do it the fastest, but be pretty dangerous. Unless a guy is experienced in using one for general work, I sure wouldn't recommend he jump into profiling something with one.

This is the kind of thing that happens when one grabs/kicks back/eats your face...

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and just for the record, he DID make it out okay.... amazingly
 

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Another way to profile is to scribe your blade in the metal and drill holes kinda close together around the scribe lines then use a hack saw to cut out between the holes. A little work with a file will take you right to the scribe line.
 
Ahh...nothing like a good bit of gore in the morning! :)

They can kick, and discs do break. Keep your lines straight and nibble away towards the profile, then clean up the profile with a grinding disc. If you respect the tool, you will be much safer in everything you do.

--nathan
 
NickWheeler said:
An angle grinder will do it the fastest, but be pretty dangerous. Unless a guy is experienced in using one for general work, I sure wouldn't recommend he jump into profiling something with one.

This is the kind of thing that happens when one grabs/kicks back/eats your face...

standard.jpg


and just for the record, he DID make it out okay.... amazingly
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Can we all say full face shield?

I know that smarted.

Gloves, full face shield and respirator are a must.

I had a good friend that ate a chain saw when it kicked back off its nose wheel; It almost killed him.

Thanks for posting the pic; its worth more than a thousand words.:thumbup:
 
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