cutting with angle grinder

[callum12 256]

Hi all,
sorry this is probably a really basic question but up until now I've been machining stuff on a lathe and milling machine more than fabricating. 
anyway, i finally got an angle grinder (how did i do without it!!) and i can't seem to find a good guide to cutting using one. so far i found out that you cut from the back to the front, don't twist (common sense really) and let the tool do the work. but I'm still unsure about the actual cutting technique, do I go all the way through in one pass or do i go back and forth over the whole piece until i go though? 
any other tips and tricks would be great  
thanks all,
callum 

[cleat 4,936]

I have cut lots with an angle grinder. Use the thinnest cutoff wheels you can find for fast cutting.

To cut straight down you must ensure you hole the grinder level. To cut straight on a horozontal plane on a flat surface I find it best to make a shallow cut following the line then depending on the thickness being cut either make the final cut at this point or do more shallow cuts gradually going down through the material.

With a good grinder and good wheels you can cut very thick metals.

Cleat

[callum12 256]

ok thank you, so it depends how thick the material is as to what method you use.
I got a bosch 701W 4.5" grinder, all the reviews were good and seem great so far. 
thanks again
callum

[19richie66 16,880]

I have a 4.5" grinder that I made a dedicated cutoff tool out of. I always try to mark the material, make a shallow initial cut all the way across (if flat) and I move it back and forth slowly till it starts getting almost through. Once it goes through then I just keep it going. For pipe I use a hose clamp and tighten it down and make my mark along the edge of the clamp(remove it of course before cutting). I cut through the inner wall and then go around the whole thing. Solid steel I just work it from top to bottom till it is almost halfway through and if possible rotate it to finish. Be careful cutting things that have been welded and might have a little tension in it. I have had cuts close in on my disc and stop it. If this happens and damages the disc in anyway, trash it. I have had one come apart. Not pretty. Good luck. Mostly common sense and wear safety glasses and gloves. 

[wheeledhorseman 573]

I remember thinking much the same thing when I got my first angle grinder - why didn't I buy one of these years ago? A bad boy bigger one followed for cutting larger stuff and then a small air line powered one you can get into awkward places with.

Don't skimp on eye protection (we've all been there I guess) - a sleepless night followed by a trip to local hospital casualty dept reinforces this point and just one bit of grit or steel is all it takes! Also, one tiny particle of steel burning as it flies through the air conatins very little energy, thousands hitting the same spot continuously can melt synthetic materials (like a sweater) or set fire to cotton (like jeans).

Practice makes perfect when it comes to cutting good straight edges but we all have off days (wel I do) so on critical stuff like cutting sheet I cheat by clamping a length of flat bar to the sheet as a guide - works well.

As has already been mentioned use the really thin cut off discs - you may have to shop round to get these, they don't do them in B&Q and let the disc cut at it's own speed - force it and you'll get through lots of discs.

Enjoy!

[callum12 256]

yes I've got the proper wrap around glasses and i WILL be leaving the guard on, no excuse for me as my grinder as got a tool-less adjustment for the guard.
I got my grinder from B&Q and got a pack of 5 2mm cut off disks just to get me started, they did do 1mm cut off disks but not in a multipack. one I've used up my fat disks i will go to a place called Jones and *****, they do bits like that and cheaper than B&Q to get some thin ones.
I the first thing i cut was a piece to 10mm thick 75X50mm angle iron for project agri-800, first cut was a bit dodgy but the second cut was massively better. 
what do you guys prefer, flap wheels or grinding disks? I've been using a flap wheel and am very impressed with it so far. plus i find the noise quite satisfying! haha 
thanks again,
callum 

[meadowfield 2,545]

Eventually you'll have 3 grinders... One to cut, one to grind and one with a wire wheel on

the 1mm discs are the dogs, you can get cheap packs of 25 for a tenner. The norton ones from screwfix cost more but last 2x, providing you are never tempted to grind with them

I'll second the eyewear...

[callum12 256]

Norton, i'll remember that, I've got a screw fix nearby. how tough are the disks? I'm going to wait until one wears down too much and try to snap it to get a feel for how strong they are (i mean snap with my hands, not induce disk shatter! ). 
looking forward to grinding rather than filing for 15 minutes! 
callum

[Racinbob 10,269]

I just cut through a 1 3/8" crankshaft this morning. I just hold the grinder so it's easy to steady it and throwing the bulk of the sparks away from me. I thought I'd try the cheap Harbor Freight wheels and figured they wouldn't last long. I was amazed that I only took off a couple of thousandths. I can't over emphasize the eye protection thing. They will shatter and at the RPM they are cranking the pieces can do a lot of damage. I wear a full face shield.

[19richie66 16,880]

I was cutting a piece of flat steel one day,(too lazy to get out the plasma cutter) and smelled something burning. I have a lot of leaves around my work area due to an oak tree right over my shed.I stopped the grinder and started looking around for what was burning only to find out it was my shirt. Needless to say that shirt became a rag. Be careful as it's not just the eyes and fingers you have to worry about.