the grinders are the ones that have a drill type switch with an option of locking them on (zardos!) 
http://www.aldi.co.uk/uk/html/offers/offers_week12sunday08.htm

http://www.aldi.co.uk/uk/html/offers/offers_week12sunday08.htm
Think it's probably going to run at too high a speed for metal.
Although I do have a dimmer plug, would I be able to use this to safely slow the saw down ???
Jim
Have they got the size of the discs wrong on that small grinder? I always thought the sizes were 100mm & 115mm respectively. I’m thinking they may be ok just to keep for grinding. It would save time taking the cutting discs out of my Bosch grinder.
No, they are 125mm. I bought some a while back when I bought the grinder, now I have a dead grinder and loads of discs that are too big for the Hitachi one I replaced it with.
I killed 2 Black N Wrecker 115mm grinders in a day once, fettling slabs. Replaced it with a bosch, which is still going 10 years on.
Phil
Woz-is it the guard that prevents your 125mm discs from fitting new grinder ? Also when you say you bought some a while back when you "bought the grinder", are you referring to this Aldi grinder? If so, how much use did you get from it?