I know there is a difference in the hole of a 7" disc and a 4" disc. I plan to remedy this by having an adapter fabricated.
Will the larger disc have an adverse effect on the grinder? I plan to use it to cut angle bars and similar materials. The small disc just doesnt allow enough view for an accurate cut. and i dont have the money to buy a cut off saw.
Re: Putting a bigger disc on a 4" angle grinder
I imagine it shouldn't be a big problem for the grinder just don't force it too much.
Re: Putting a bigger disc on a 4" angle grinder
also don't see much or adverse effect on the grinder as well. maybe some on the user. this will potentially be a safety hazard IMHO. but that just me...
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Re: Putting a bigger disc on a 4" angle grinder
I agree with Timber 100% on the safety issue. In fact, I kind of like it that my el-cheapo MIC grinder's slide-type power switch will no longer lock in place. This way if drop it just turns off and won't be spinning out of control ... imagine one of those with a diamond cutter spinning at 10,000 rpm ... heck an abrasive wheel is scary enough.
Re: Putting a bigger disc on a 4" angle grinder
Ditto on the opinions of Timber and Incc63 on the SAFETY ISSUE.
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Re: Putting a bigger disc on a 4" angle grinder
Agree with others that it's a safety issue.
At 10,000 RPM the outside edge of the 7" disc would travel much faster than those of a 4" disc. That's why larger angle grinders have slower rpm.
Re: Putting a bigger disc on a 4" angle grinder
Don't even think about it!!
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Re: Putting a bigger disc on a 4" angle grinder
Agree with others that it's a safety issue.
At 10,000 RPM the outside edge of the 7" disc would travel much faster than those of a 4" disc. That's why larger angle grinders have slower rpm.
I did not know that. If that's the case then maybe those disks are actually not rated for 10,000 rpm. Better not do it then. Thanks estib for sharing this.
Re: Putting a bigger disc on a 4" angle grinder
i am actually not going to hold it while i'm using it. i'm planning to buy or fabricate an angle grinder stand (which i asked about in another thread). this will serve as a mini cut off saw.
regarding the rpm rating of the disc, as long as the disc's rating is above that of the grinder, it'll be ok. 10,000rpm (or whatever the rating) is the same for all sizes of disc. as long as you don't exceed the rating, it is ok.
Re: Putting a bigger disc on a 4" angle grinder
well it seeems you did not need any answer to begin with, word of caution lang to others, flying disc that break off will tend to cut flesh when they hit you. buying a cut off disc sander that accomodates 7" will most likely have a cover that will protect you in any eventuality. Always respect powertools, they can damage you more that you can them... Practice safety! Always...
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Re: Putting a bigger disc on a 4" angle grinder
Just caught up with this thread, Generally the safety advice given is true - the peripheral speed makes it a doubtful thing. If the difference is only an inch, maybe OK - I used 5 inch discs on a 4 1/2 grinder, no problems. But any more - watch out! Also need to remove the guard - are you comfortable with that?
A disc can cut a lot of soft tissue in a VERY short time! How many fingers do you need?
:rolleyes:
Re: Putting a bigger disc on a 4" angle grinder
Just to add on the safety issue of having a bigger disk (7") to a 4" grinder. Every tools are designed for certain application, that's why every grinders have different RPM rating. For the 4" and 5" have an average of 11,000 rpm. for the 7" an average of 8,500 rpm. And for the 9" an average of 6,500 rpm. While the cut off saw an average of 3,500 rpm. The RPM and the disc diameter relate to each other because there is an International Rotational Standard that sets the speed limit (Linear Speed) of the rotating objects. The Linear speed must not exceed 80m/s or you will be at greater risk of having a broken flying disc. To know if the disc you will be using conforms to the standard, you may use the formula - Linear speed (L) = 3.14 x diameter of the disc (d) mm x RPM divide by 60 and 1000.
But strongly advised you should not use the 7" disc to 4" grinders. Much better to buy 7" grinder for your application.
Re: Putting a bigger disc on a 4" angle grinder
Just to add on the safety issue of having a bigger disk (7") to a 4" grinder. Every tools are designed for certain application, that's why every grinders have different RPM rating. For the 4" and 5" have an average of 11,000 rpm. for the 7" an average of 8,500 rpm. And for the 9" an average of 6,500 rpm. While the cut off saw an average of 3,500 rpm. The RPM and the disc diameter relate to each other because there is an International Rotational Standard that sets the speed limit (Linear Speed) of the rotating objects. The Linear speed must not exceed 80m/s or you will be at greater risk of having a broken flying disc. To know if the disc you will be using conforms to the standard, you may use the formula - Linear speed (L) = 3.14 x diameter of the disc (d) mm x RPM divide by 60 and 1000.
But strongly advised you should not use the 7" disc to 4" grinders. Much better to buy 7" grinder for your application.
thanks for the explanation. this clears up some of the safety issues.
