Noob question about grinder...

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Ive got a 10 amp 4 1/2" Dewalt angle grinder. Ive never used a grinder amd am just learning to weld. I bought some cheap harnor freight cut off disk to practice with. Im not sure if I am installing the disk wrong or if its just the cheapness of the disk but after using the disk for 20 or so seconds the thin mwtal piece that goes around the hole in the center of the disk comes loose and the disk starts coming apart. I am putting the disk on  bolt with the lettering on the disk facing the grinder then I put the nut on behind it tightly with the wrench included with the grinder. There seems to be some play in the disk even when its locked down. I am using the disk to cut 1/4" steel plate
Reply:Flip the nut over so the recess faces the disk and buy better disks.My name's not Jim....
Reply:Originally Posted by BoostinjdmFlip the nut over so the recess faces the disk and buy better disks.
Reply:IIRC the nut says something like "this side up for 1/4" disks.  The other side is for thinner.  I use dewalt cut off disks.  They aren't too bad at $1-$2 each.My name's not Jim....
Reply:You have to match the flange and nut piece to the style of disc so that you are clamping it and not distorting.  Cutting discs and thin discs are especially dangerous because they can fly apart from running above rated rpm and from rough handling.  If you are a novice with cutting discs a face shield might save you some cosmetic surgery.  Think about buying grinding discs that are much thicker and better suited for 1/4 inch thick material.  Also don't load up your grinder and slow the speed too much.  It will overheat and cook the windings.
Reply:Originally Posted by lotechmanYou have to match the flange and nut piece to the style of disc so that you are clamping it and not distorting.  Cutting discs and thin discs are especially dangerous because they can fly apart from running above rated rpm and from rough handling.  If you are a novice with cutting discs a face shield might save you some cosmetic surgery.  Think about buying grinding discs that are much thicker and better suited for 1/4 inch thick material.  Also don't load up your grinder and slow the speed too much.  It will overheat and cook the windings.
Reply:Whether a little or a lot, even pressure is the most important.My name's not Jim....
Reply:I had to turn the nut over on my 4.5 grinder when I changed over to a flap disk. Other wise it did the same thing it would just spin around on the shaft.
Reply:They sell a recessed washer that's for use with  thin cut off wheels and diamond wheels.http://www.homedepot.com/Tools-Hardw...&storeId=10051 Attached Images.No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:i think Bhardy nailed it.  Depending on whether you are using a grinding stone (~1/4" thickness) or a "zip cut"; cutting disk will dictate what side of the locknut you have down.  On most 4.5" angle grinders you will find a "step up" locknut on one side for use with 1/4" stones and a flush other side (or nearly flush) for use with 1/8" cutting disks.   As others have mentioned don't load the motor and use consistent pressure to avoid making a mess.  It has worked for me so far (crosses fingers).  I rarely use 4.5" electric grinders since I've gotten into a good boiler shop; all of our stuff is air so if you bog it down too much you wont burn out motors rather it will just stall.   Above all, remember to be careful as everyone will tell you... a broken stone, let alone a cutting disk can make a very serious mess of you when it's running at 10+k rpm.  Probably over stated and over worried about, but when you are talking about seriousness of a potential injury/failure of that magnitude you can never be too safe.   Someone once told me that an angle grinder is easily the most dangerous tool we use as professionals and I am very much inclined to agree.  Anyone else have any input?  That's just my .02 but in my experience it has been fairly accurate and sounds advice...  Oh, and leave the ****ing guards on...  if you cant get at the spot you need too; the grinder you are using is the wrong tool for the job, switch to a die grinder or some other tool. PPS, also, always wear a grinding shield (and have it down... lol needs to be said).  I dont care how tough the guys you work with might tell you they are having your eye(s) dug out by an eye doctor is a miserable experience..  I could go on for days about grinder safety and don't pretend to be any sort of expert, but i know from what I have read here and elsewhere that I really dont want to be and logic tells me given the unpredictability and severity of accidents and near misses with them I dont want to be.  Suffice to say everytime i pick one up still im am apprehensive.  I know when a shear, ironworker, pressbreak etc will relieve me of whatever appendage.... i cannot foretell when my grinding stone or zipcut will bind, explode or kickback and ruin my day.  err on the side of caution.
Reply:What is the correct motion so to speak that I should use? Forward or forward and backward like a sawing motion?
Reply:wear safety glasses under a full face shield!"Where's Stick man????????" - 7A749"SHHHHHH!! I sent him over to snag that MIC-4 while tbone wasn't looking!" - duaneb55"I have bought a few of Tbone's things unlike Stick-Man who helps himself" - TozziWelding"Stick-man"
Reply:i have a bunch of small grinders/ theyare without a doubt the most dangerous tool i own . they will kick off the metal you are cutting , land in your lap and crawl their way right into your guts if they can. and so fast you cant even say when it happened.be careful..gloves,faceshiled,heavy sweatshirt..
Reply:Originally Posted by bnew17What is the correct motion so to speak that I should use? Forward or forward and backward like a sawing motion?
Reply:While Harbor Freight tools might be acceptable for some things, I find that tools that need an edge don't keep them, and grinding wheels, stones, etc wear much much too fast.  And at 10-20K rpm they scare the crap out of me (die grinder).Homedepot carries better stuff, the LWS carries really good stuff (but at almost full list price).  So Homedepot normally wins that one.Con Fuse!Miller Dynasty 350Millermatic 350P-Spoolmatic 30AMiller Multimatic 200Hypertherm PowerMax 1000G3Miller Maxstar 200DX
Reply:After having a 4 1/2 grinder kick back wind up my sweatshirt, then eat a hole in it and give me some funny shaped swirl road rash around my navel I wear a leather apron when working with the beast. And I've tried just about every type abrasive that HF sells. They all suck. Half the price and last 1/3 the time of the good stuff .Last edited by AZDoug; 03-18-2012 at 05:51 PM.Beer has food value, Food has no beer value
Reply:I bought this apron http://www.duluthtrading.com/store/m...ons/96543.aspx its from Duluth Trading Company. Its made from the same type of material that fire hose is made from. It is with out a doubt the most comfortable apron I have ever had. Also makes great protection for you mid section when grinding.
Reply:Please listen work safe glasses and a face shield do not remove the guards and gloves and the apron or coat . Long sleeves too  !!   John PS I got a piece of wire wheel in my eye with glasses , goggles and a shield bad luck but it happened .
Reply:Also paddle switch grinders only from now on , and dont tie a knot in the cord . Try chasing a dropped grinder on the  ground or your chest or leg running !!!
Reply:I bought my Milwaukee 4 1/2" grinder in 1976 at the LWS for $110( alot of money then) and still use it almost every week. Key word here is GRINDER not cut off tool. I use flap dics and grinding wheels only.If I have to cut some steel or other metal I have a air highspeed cutoff tool, a torch (1970),portaband and stand (1980's), 4x6 band saw (1981), plasma cutter (1988), three hack saws (????), Craftsman (1968 or so) and Dewalt sawzall (1990's), 14" chop saw (1992),cutting sticks for the arc welder and a lot of other safer ways to cut things. I even remember putting a fiber metal cutting disc on my circular saw.Now you can buy a  circular saw just for metal.I can't see people useing a 4 1/2" grinder as a cutoff tool it is unsafe.www.georgesplasmacuttershop.comPlasma Cutter and Welder Sales and Repairs--Ebay storeTec.Mo. Dealer Consumables for the PT and IPT torch's
Reply:I've heard awful things about HF abrasives, but haven't personally tried them.I had one job that required cutting off some pieces of 1/4" steel for a friend.  He brought four DeWalt cutoff wheels from HD for me.  I burned through all four wheels and was less than half done with the cutting.  I put one of my new Metabo wheels onto my grinder, and finished the job with plenty of room to spare on that wheel.Go to the LWS.  At mine, they sell Metabo, Sait, and Norton wheels for less than HD, and they will far outlast anything you get at a hardware store.Oh, and forget about HF cutoff wheels.