Daryl Posted September 1, 2008 Share Posted September 1, 2008 Having recently purchased a sale bulk pack of grinding discs, and the results from that, I feel it important to advise everyone about the quality control of items that are not common name brands. Normally, the discs I purchase for my 8" Makita angle grinder were either Norton or Walter brand. These discs remove material very well, produce comparitively minimal dust, and last quite long. I happened across a bulk pack of ten grinding discs for a price that I felt may give me some cost savings (I, like everyone else, has to be vigilant for econoomy). The first disc I installed on the grinder was severely out of balance, even though visually it displayed no runout when turned on the grinder; the same for the next four in the pack. The fifth one only lasted about thirty seconds of light grinding before it suffered a catastrophic failure. When I first felt the disc starting to go, I had just pulled my finger from the trigger and was turning it away from my body when it let go. I now have several bruises on my legs and stomach, as well as a few dents and dings in the wall and cieling of my shop. Feeling that I may have been to blame, I examined the remaining discs in the pack - the media or particulate matter displayed cracks or hazing right on the surface. I have now destroyed the remaining discs with a hammer, to prevent the being salvaged by someone else. All this because I thought I saved 10%. . For those of you purchasing bargain 'stuff': caveat emptor. Quote Link to comment Share on other sites More sharing options...
welder19 Posted September 2, 2008 Share Posted September 2, 2008 Unfortunately you can rarely save on grinding and cutting supplies by going with a lower cost no name brand, however there are sometimes that it does pay off but unfortunately it is a matter of trial and error to find the few that cost less but do work as well as the high quality, high cost brands. Norton, Morse and 3M are the brands that I use to cover just about all of my cutting and grinding needs, they cost a little more than most but last a lolt longer and work much better so there fore they actually cost less in the long run, plus a lot of tooling is time consumeing to change so there fore you loose a lot of valuable time also. welder19 Quote Link to comment Share on other sites More sharing options...
highlander Posted September 2, 2008 Share Posted September 2, 2008 Darryl, Thank you for posting this. Safety is number one, and advice from personal experience is a great thing to give. All my grinding discs are norton or dewalt. I had one harbor freight one break apart on me(i got out unscathed, as it broke apart as i turned the grinder on so it was fairly low rpm) and won't buy anything but quality now. Quote Link to comment Share on other sites More sharing options...
mike-hr Posted September 2, 2008 Share Posted September 2, 2008 Life's too short to spend time with inferior abrasives. Buy the best, get the job done fast, then go fishing. Quote Link to comment Share on other sites More sharing options...
Ten Hammers Posted September 2, 2008 Share Posted September 2, 2008 Don't forget Pearl abrasives. This wheel may or may not have been designed for stainless. It works GREAT on carbon. I have been hounded for the pic saying that I used the wheel too long and had no guard. Your mileage may vary. This wheel is on a Bosch 4 1/2" and I have a Milwaukee with flap wheel. I have a 7" makita with makita wheel, die grinder with cutoff and a belt grinder. The Pearl wheel will not only grind smooth but cutoff and cut welds handily. As it gets smaller it may have uses in tight applications. I do NOT use wheels with fiberglass re-enforcement. To each his own. Swap meet cheap abrasives are just that. Mystery meat. Norton, Makita, Pearl are good choices. SOME rock wheels are now made in CHINA and the quality has went. They are junk ( and yes some are name brands ). Sharp good files and hot files still are included in my inventory as are emery boards, nail files and the striker from a book match. Quote Link to comment Share on other sites More sharing options...
ironrosefarms Posted September 3, 2008 Share Posted September 3, 2008 I also don't like purchasing discs from the Lowes, home depot or menards... I have found far to often that these discs get dropped or beat around causing weak spots in other wise good brands. I will buy from our local hardware store as the guy is very careful with his stock, other wise I go to a welding supply house or similar place to avoid the mass handling and flunky careless stock boys that they tend to get... Quote Link to comment Share on other sites More sharing options...
Dave M Posted September 3, 2008 Share Posted September 3, 2008 I purchased a sleave of grinding discs from one of those cummings tool sale trucks, They were for my 4.5"grinder. Same story as the others I got what I paid for. They did not spin balanced and they made a ton of dust for very little stock removal. It takes 5 of them to do the work of 1 good norton disc. Well I wont do that again. Quote Link to comment Share on other sites More sharing options...
LarryM Posted September 4, 2008 Share Posted September 4, 2008 (edited) I get my 10% discount because I buy a whole box at a time. Or as many as it takes to get a break in price. I agree a cheap exploding grinding wheel not worth bring in the shop. BTW I had to learn the hard way too. Larry Edited September 4, 2008 by LarryM Quote Link to comment Share on other sites More sharing options...
Woody Posted September 4, 2008 Share Posted September 4, 2008 Always remember that the cheapest thing you can buy is often the most expensive thing you can own. If cheapest were best, we would all be driving YUGOs. I have used some cheap grinding disks and while they didn't come apart, they didn't last very long so there was actually no savings. Remember to always check the maximum recommended rpm of the disk against the max rpm of the grinder. Quote Link to comment Share on other sites More sharing options...
David Einhorn Posted November 16, 2008 Share Posted November 16, 2008 I have also noticed that the cheaper discs don't have the industry standard codes printed on them to tell you the properties of the disc. I look for an "N" in the code to tell me that the disc is designed for fast material removal.... if I remember correctly. Quote Link to comment Share on other sites More sharing options...
rthibeau Posted November 16, 2008 Share Posted November 16, 2008 The least expensive, but not cheap, abrasives I could find I get from AAAbrasives online. I buy quantity to get the lowest price. Flap Discs Quote Link to comment Share on other sites More sharing options...
David Einhorn Posted December 1, 2008 Share Posted December 1, 2008 (edited) I always look for the specification codes on the grinding discs I purchase. If there is no code then I assume that the disc is cheap junk and not worth purchasing. I have been informed that the codes are "industry standard codes". My preference is code A24N for fast stock removal. In case there is interest here are some of the relevant codes for steel: Specification Application ------------------------------------------------------------------------ A24R......General purpose wheel for heavy working conditions. Long life, good stock removal. Used for Iron, Steel, normal ferrous metals A24N......General purpose wheel for normal working conditions. High stock removal. Used for Iron, Stainless Steel. Z-A24R....Zirconium abrasive wheel special designed for extremely tough applications. Has long life and high stock removal. Used for Iron, Stainless Steel, Forgings. A46N......Special Wheel for aluminum and nonferrous metals. Used for Aluminum and other nonferrous metals. I found this information at: www.franks-supply.com Edited December 1, 2008 by UnicornForge Quote Link to comment Share on other sites More sharing options...
Frosty Posted December 1, 2008 Share Posted December 1, 2008 Good info. Thanks. Frosty Quote Link to comment Share on other sites More sharing options...
rustyshackleford Posted December 2, 2008 Share Posted December 2, 2008 I recently bought a hitachi 4.5 grinder, and put my old 4" dewalt disc on it, works fine. I went to put a new 4.5" delta cutting disc on it, and it is loose as heck! the 5/8" arbor (which was what the 4" disc hole was) was too small for the 7/8 disc. Checked the manual, and it says it's a 7/8!!! I don't get it. I even tried to put on the disc included with the grinder, and I can definitely feel an eccentricity when it runs, enough to make it uncomfortable to use. Quote Link to comment Share on other sites More sharing options...
ptree Posted December 2, 2008 Share Posted December 2, 2008 I buy Norton or a Norton house brand that I get from Hagemeyer. Off brand will hurt you. Remember that there is no rule of law in China, and since lawsuits don't much work there either, most anything goes. Do each and every one of you have the guards on the grinders they came with? if not PUT them on. Can't find the guard? scrap it! One shop I worked at had 2, TWO! deaths from no guard 9" grinders exploding. One killed the operator, the other case the wheel half slit the throat of a guy 10' away. These happened not long before I started there. I went on the war path when I found not a single guard on a grinder. I suspect my scrapping every one I found by use of a bandsaw may be why I only lasted 3 years there. Bandsaws are great for nylon lift slings that are frayed as well :) Quote Link to comment Share on other sites More sharing options...
Quenchcrack Posted December 3, 2008 Share Posted December 3, 2008 Abrasives seem to be another item that can be manufactured to look just like a real one but be almost useless. I prefer Arkansas stones to sharpen my carving tools. However, I bought a man-made stone from HF and discovered that as I used it, no sharpening was taking place. I was just wearing the grit away from the stone. I tossed it and bought a $25 Norton combination India Stone. What an incredible difference! No grit is removed, just the steel from the tools. Don't waste money on cheap abrasives. ptree: both of my grinders have the original guards in place. As your post indicates, high speed grinders are weapons of fast destruction without the guards. I also use a full face shield when I grind. Not many opportunities for a blind metallurgist. Quote Link to comment Share on other sites More sharing options...
Daryl Posted December 4, 2008 Author Share Posted December 4, 2008 Check out Manufacturers' Health & Safety Association Quote Link to comment Share on other sites More sharing options...
ptree Posted December 9, 2008 Share Posted December 9, 2008 Quenchcrack, BRAVO! Remember all only protect the eyes etc you want to continue using. Quote Link to comment Share on other sites More sharing options...
jayco Posted December 10, 2008 Share Posted December 10, 2008 I had been using an assortment of 'cheapie' angle grinders for some years now....and going through a lot of the 'cheapie' grinding discs as well. Finally, all those 'cheapie' grinders sort of "gave up the ghost", and I bought a name brand grinder........not a real expensive one, just one with a name you would recognize. When I opened the box, I discovered there were 3 discs in there (same brand as the grinder).....and I thought "Gee, I'd better get some more discs....quick!" Funny thing is.....I haven't worn out the first disc yet.....even though I've done a lot of grinding with it. I guess that old saying is true.....You do get what you pay for! James Quote Link to comment Share on other sites More sharing options...
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