How do I choose angle grinder?

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Jumanji95
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How do I choose angle grinder?

Post by Jumanji95 » Sun Jun 17, 2018 9:02 pm

Larger disc ones seem to be high power and low rpm
Smaller discs the opposite- how do I decide please?
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Re: How do I choose angle grinder?

Post by ayjay » Sun Jun 17, 2018 9:59 pm

Jumanji95 wrote:Larger disc ones seem to be high power and low rpm
Smaller discs the opposite- how do I decide please?
Horses for courses: what do you plan to do with it?

A 9" angle grinder is a bit of a beast to control compared to a 4", which is all I've ever needed as a chippy.
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Re: How do I choose angle grinder?

Post by big-all » Sun Jun 17, 2018 10:20 pm

pi R Squared means the outer edge goes 3 times the speed so a 4" disc will go 3 times the speed so higher rotation wont be a problem
where as a 9" disc needs to rotate perhaps 60% slower to give the same cutting edge speed
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Re: How do I choose angle grinder?

Post by Hitch » Mon Jun 18, 2018 3:36 am

What do you want one for...?
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Re: How do I choose angle grinder?

Post by Jumanji95 » Mon Jun 18, 2018 4:40 pm

I want one for various stuff- cutting wood,metal, various diy for my project motorcycles. Sometimes I grind away the rivet on the masterlink of a motorcycle chain, so that it can come undone and a new chain put on. Grind away the head of stripped screws so they can pop out. Grind away flaky very sticky rust on exhaust headers with a wire wheel.
Cut off the exhaust catalytic converter from the main exhaust and attach a new tube with exhaust clamp (can't weld yet nor do I have equipment- totally new to diy) so that the exhaust can sound obscenely loud when engine running :) etcetera etcetera. No big DIY stuff for the home. Most of my work is for cars and bikes.
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Re: How do I choose angle grinder?

Post by Bob225 » Mon Jun 18, 2018 4:49 pm

A good 4" grinder will do, you don't use a grinder for cutting wood unless you like clouds of wood smoke, For rust removal or cleaning use a flap disk

Whats you budget ? they range from £30 up into the £100's
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Re: How do I choose angle grinder?

Post by Hitch » Mon Jun 18, 2018 9:04 pm

So you deffinately want a 4.5" or 5" one then. 5" tend to be the more industrial end of things, 4.5" or 115mm is the norm for DIY type ones.

I'd steer clear of the very cheap (Lidl/Challenge etc) and buy a branded one. They tend to be much smoother running and less vibration. You could pick up a basic Blue Bosch or Hitachi for under £40.
I use grinders a lot, they are the only two brands that last us in the workshop. (although the more industrial models)

Get yourself some reasonable discs too, cheapo ones are a false economy, and just plain nasty to use.

Norton, 3M, Flexovit, Klingspor are all good brands that are easily gotten hold of.
A flap disc is handy for lighter duty deburring, and cleaning up. The thin 1mm cutting discs are fantastic, just dont force them or put side loads on them.
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Re: How do I choose angle grinder?

Post by Bob225 » Tue Jun 19, 2018 11:17 am

Don't forget a pair goggles, glasses or face shield and a pair of decent gloves - ear plugs or ear defenders are a must tooo

There called death wheels for a reason.
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Re: How do I choose angle grinder?

Post by Jumanji95 » Tue Jun 19, 2018 11:30 am

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