best way to cut metal for a new guy

O

obsessis

Joined
Jul 2, 2009
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I don't have a bandsaw. I have a scroll saw but no special metal blades. I have a hacksaw. I have a 4.5" angle grinder. I have a Dremel tool with the special Metal cutting discs.

Do any of you cut metal with what I am using? I just went out and tested the new Dremel discs and they do seem to cut, slowly, but I'm not too sure how it will do when the cut gets deeper (the metal is .25" thick). I was thinking about starting with the dremel and then try to finish up with the hacksaw but that would take forever.

Do you have any suggestions? Do I need to totally cut it to shape or can I have it really rough (square-ish) and try to grind off most of the metal? I'm not really sure how formed the metal has to be before I start grinding it away with my sander.
 
Scribe your outline on the steel and use the angle grinder to remove excess steel.
Stan
 
You have a 4.5 inch angle grinder; which I believe is one of the handiest tools in the shop.
I have two that I use constantly.

You can purchase 6" cutting disc for it which will eat 1/4 inch carbon steel.
The disc are quite thin but very tough also. They are made for cutting steel.

I like the ones made by Metabo.

You of course must remove the guard from your grinder to mount them, I am not recommending, but you can. I did.

Best of luck and always wear gloves while operating.

Fred
 
Gloves and eye protection! I used a 4.5" angle grinder using the 4.5" cut off discs and grinding discs to profile knives for quite a while before I picked up a bandsaw. Handy indeed. You'll also want to wear some hearing protection.

--nathan
 
Well Angle Grinder it is. I knew it was a good purchase.

Dumb Question: Why do you recommend wearing gloves? I'm assuming you have to put the steel in a vice or something to cut/grind it....

When you use the grinder, do you put the handle in the side or on the top? I imagine putting it in the top to use a cutting disc and then going straight down would be the best for cutting, the side for grinding.

Am I right about the vice to hold it?
 
Yes, you place the steel in a vice. Gloves are handy because depending on where the sparks are getting thrown, they will often time end up flying directly onto your exposed hands. Do that for a long cut, and not only will you get tons of little metal splinters that can sometimes be irritating, but it can get a little warm as well.

You'll have to play around with the best way to cut for you, but be concious of where the sparks are flying. I use a full face sheild when grinding with an angle grinder becuase it's much more effective at protecting your eyes as well as your face. You can pick up a face sheild for cheap at hardware stores or Harbor Freight. Like I said, just be concious of where your sparks are flying so you don't inadvertantly damage or dirty something up.

--nathan
 
Yep the vice will work good,watch where your throwing sparks as you caan get a fire going pretty easy.Used to have a small cheap H/F vice mounted to a stump outside the shop for this purpose.
Stan
 
wasnt there someone on the forums here that had a small fire from sparks not too long ago? seems like i remember some boxes or something cought.

so yes be careful... also the sparks can set you on fire as well...... dont let them hit you in one spot for too long. i caught a shirt on fire last month with my angle grinder!

good luck

jake
 
Not a small fire....
Raymond Richard burned his entire barn and blade shop down while grinding. Lost all his equipment, several farm trucks, the hay, etc. Not his happiest day.
Keep a hose and a fire extinguisher handy, and think about where the sparks are going.
Stacy
 
Hi Obessis,

Welcome to the Blade Forums and knife making! +1 one on pretty much what everyone has said.

In addition to making sure your cutting from a portion of the disk and in a direction that makes sure the sparks are being thrown AWAY from you, make sure you can hold and control the grinder well. If you haven't used an angle grinder much it will take a little getting used to. Try to brace your forearms and triangulate your grip as much as possible to be as steady as you can. Go at it slow and easy. If you take off the safety guard (as I and most folks do) you have to be especially mindful of where on the circumference of the disk you are doing the cutting. The disk can bind and/or grab more readily depending on where its cutting from and how well you are holding the machine. It's kind of a zen thing, but you'll get it as you tune in to what you're doing.

You asked about where to place the handle. Good question. It kind of depends on where you are standing and what side of the metal you are working from. That is why you can change it up. There are several different disk options you can put on these things. I tried larger disks before, but found them harder to control, although they can get the job done faster if your grinder is strong enough. (I usually am running cheap wimpy ones. :D) Get disks with the right size hole to fit your arbor. The thin ones are for cutting. The thicker ones for grinding. You can get various wire wheel brushes and sanding attachments too. You can also clamp up your grinder in your vise to simulate a bench grinder.

Eyes, ears and breathing protection are HIGHLY recommended! Make sure there are NO combustibles around. Don't get distracted. If the wife or kids or a friend or the dog comes around, shut it down until your work space is clear again and free of distractions!

Good luck, Phil
 
When you're using a cut off wheel, a few things you should keep in mind.
As mentioned before, wear safety glasses or a face shield or both, wear gloves, have a fire extinguisher.
But most importantly, don't let the grinder kick, make sure you're cutting on the correct side of the wheel. Otherwise the grinder can kick and put you in the hospital. These wheels don't slow down when they go into you. Also, check your wheels before you use them. If they're cracked then don't. I've had wheels explode tons of times. I even know a guy that had to get 5 stitches in his face because of an exploding cut off wheel.
And of course, use the guard. If you want to use 6" wheels, but a 6" grinder.
Also, I don't use a handle on anything smaller than a 8" grinder.
Be careful and have fun.
 
Exploding discs are a great reason for a face shield and gloves. And the dust mask as mentioned is a great idea. The wheel disappears as it is used. Guess where it disappears to? Yep, the air you're breathing.

--nathan
 
silver_pilate said:
Exploding discs are a great reason for a face shield and gloves. And the dust mask as mentioned is a great idea. The wheel disappears as it is used. Guess where it disappears to? Yep, the air you're breathing.

--nathan
Click to expand...

Great words of advice. The reason I still have all my fingers is because I was wearing gloves when an 8" disc exploded... Even with gloves it almost took off one of the fingers. Gloves are extremely underrated when working with metal I think.
 
Dang, sounds like you better just stick with the hack saw! I guess this is as good as an introduction to one of the major aspects of knife making as any: it is dangerous!
 
strahd71 said:
wasnt there someone on the forums here that had a small fire from sparks not too long ago? seems like i remember some boxes or something cought.

so yes be careful... also the sparks can set you on fire as well...... dont let them hit you in one spot for too long. i caught a shirt on fire last month with my angle grinder!

good luck

jake
Click to expand...

Yeah, been there done that, NEVER EVER EVER wear synthetic fabrics when working around heat sources, that includes sparks. Cotton or leather.

Not that many people don't do it, I recommend against using an over sized disk in a 4.5" grinder, generally it will over speed the disk which if it breaks can destroy your hands and possibly kill you, at least doing damage to your body.

Just not worth the risk imo. Use a proper sized disk and cut in straight lines.

The brand I use is Metabo.
 
There is nothing like the voice of experience; it can and does speak volumes, as it does here.

As and after thought, keep the steel wool away from the spark stream, coming off the disc. It will ignite with little effort.

Work safe, Fred
 
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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