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bench grinder safty

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  • bench grinder safty

    Gentlmen, Once a month we have a safty meeting on varied subjects at work. My name was picked to deal with the subject of "bench grinders" next week. We have 18 employees at this time, most of which are carpenters.They use the grinders the most for their planes and chisels. Any input about the safty/proper use of these tools would be appreciated. All of the grinders in our shops are 1 hp or less, from Craftsman on up. I have a pretty good understanding of safty but tips and proper use are needed. Thanks, Dave

  • #2
    careful of "loading" the wheel, by using soft materials like aluminum on wheels. causes the wheel to crack.


    • #3
      It can take minutes for the grinders to spin down and an unuspecting user might step upto one and not realize that it's still spinning.

      Keep the covers on all the time.

      This may be obvious but if the wheel has been dropped on the floor, then take it straight to the garbage. We all make mistakes and drop things, but no sense in causing another accident.

      Full face protection, or at the very least eye protection.

      I always use welding mask when I'm grinding, especially when I don't know the composition of the metal.



      • #4
        Make sure the work support in front of the wheel is close enough to it so that the work can't be pulled into the gap.

        Support the work on the work support, adjusting it if required. If you hold the work by hand, (as most all of us have, right?) it can be caught and thrown downwards. Sharp objects traveling out and down in the direction of feet (and especially other relevant body parts) are a bad idea.


        • #5
          Grinder safety is very important.

          When mounting wheels always use blotters on both sides of the wheel. These are the paper circles that go between the wheel and the steel flange. Remember one side is left hand thread. Don't overtighten the nuts.

          Truing a grinding wheel is making it round and helps to eliminate vibration.

          Dressing a grinding wheel opens up the grinding surface and exposes new cutting edges on the wheel surface.

          The work rest must be within 1/8" of the wheel. This was mention earlier but without a dimension. The tongue guard, the one at the top of the wheel should be adjusted to 1/8" also.

          Ringing a grinding wheel will let you know if it is cracked. Tap the grinding wheel very lightly with small hammer on the side of the wheel. It will ring if it is good. I will have a dull sound if it is cracked.

          There are grinding wheel made for aluminum and should only be used for aluminum. Grinding aluminum on a regular wheel will cause it to load and the aluminum will melt and go into the pores of the wheel. When grinding on steel after the wheel is loaded the aluminum will expand and can cause the wheel to crack and explode. This was covered before but it is so important it needed to be repeated.

          Sounds stupid, but I have been asked several times what the little tray on the front of the grinder is for. It is used for water that is used to cool off the part being ground.

          Never grind on the side of the wheel. If it is grooved the wheel is ruined and could fail.

          I will look for some of the books I got when I attended a grinding school at Norton. If I can find them and find some additional information I will post again.

          You might want to look at the Norton or other manufacturers web site. They may have a lot of information you cna use for the safety meeting. I have not looked at them.

          Good luck with the safety meeting. I think it is great to get the workers involved with the safety meeting. We did the same thing where I worked.

          Hope this helps,



          • #6
            That 1/8" dimension is important, also important to note that it is every operators responsibility to make sure that the guards are set properly. I mention this because I had a new journeyman in the shop the gap was around half an inch, he proceded to question people as to who was responsible for maintenance on the grinders, I told him it was his responsibility if he was using it. I got a blank stare and he went about his grinding (not bothering to set it up) I believe it's in the act regarding operator responsibility but I can't quote where. That was pointed out to me after a co-worker got his finger pulled into the gap a few years back.


            • #7
              To quote "alfred E neuman" What me worry? usually the attitude of all uninitated workers till the trip to the hospital. What I hate is them almost sending me through thier actions or inactions.

              I got all my fingers, but do have a few scars.

              Grinder stress, is a action of harmonics, pressure applied and rpm, I have seen hundreds of grinding rocks run at the wrong speed. When a hand grinder rock comes apart, one of the bad times the guys intestines fell out on the floor. My older brother a PE, built a box and a air motor to overspeed a like grinding rock to prove to the court it had been misused. The poor guy who was out of work got less money, but a real hard education. (he still got a lot) When you think of it, he is lucky


              • #8
                All good points. Every grinder in my shop came with a manual. In those manuals there's a pretty lengthy check list of safety precautions and operating instructions. Has anyone ever read them?
                You should be having your employees "sign-off" on instructional training. That's my tip.


                • #9
                  Check out the following web sites for more information.


                  Can't get to my books.

                  Correction to my last post should have said hammer handle and not hammer for the ring test.



                  • #10
                    All good advice so far.
                    The ring test is absolutely required for any wheel before mounting.
                    One thing I haven't seen addressed is wheel shelf life. Manufacturers put a date on the wheel. It is good for about two years, depending on how they've been stored. You can send the wheel back to the manufacturer for re-testing for a price.
                    Check out Norton's site:
                    Plenty of good info there on all abrasives.


                    • #11
                      If a wire wheel is mounted keep long hair tucked in your shirt,otherwise you could get a closeup view of the guard,and a new bald spot.
                      I just need one more tool,just one!


                      • #12
                        All that being said... There are lots of places to get grinders. HF sells them - they don't look bad. I see them on ebay, for not much more - but the advice to me was don't buy a used one... They need to meet OSHA rules because it is your eyes those rules are out to protect - and old rotary grinders may not meet standards.... It's why they might be on Ebay.



                        • #13
                          Grinders are one of the most necessary and useful tools to have handy. All the advise I've read here is sound and proper, but I think that you should present your safety information in a way that helps your audience apreciate the risk, and develope good habits and practice and yet does not intimidate them or raise their consern too far above what their experience is. If you can get a person who has used grinding wheels for years carelessly to use safety glasses that is a great accomplishment. If you can get all users to use a full face shield that is a great thing. A good practice is to have the full face shield hanger in the way of the power switch. The face shield has to be removed before the switch can be accessed. Another tip is to hold all small bits in vise grips when grinding.
                          That's all I have to add.


                          • #14

                            All good points. I do take issue with dipping tools into water to cool them, however. It is best to never let the cutting tool get hotter than you can hold with your bare hands. When it does, it is best to let it cool naturally - placing it on a granite plate will cool them quickly.

                            Dunking in water can affect hardness and temper. Dunking can impose significant thermal shock to the material and micro fractures occur at the thinnest section - the cutting edge. Carbide is more sensitive to this than HSS - dry machining with modern carbides is recommended because of this.

                            [This message has been edited by Thrud (edited 05-13-2003).]


                            • #15

                              I agree the water is not for dipping over heated tool steel. You are correct about micro cracks and temper. I don't use it for cooling tools. I do use the water for cooling steel so that it never gets so hot that you can't hold it. If you keep the temperature down by frequent dipping it will never get too hot.