Machine rebuild time - options...

[Jonathan]

I wouldn't call them bad. They were used for many years as cutting discs.

I should have said 'worse' or 'sub-optimal' instead of bad.

And how does a thicker disc increase cutting force on the grinder?

The steel is cut by the disk generating friction which subsequently melts it away. If the disk it wider the area in contact is greater, therefore for a given feedrate you have higher friction and thus a greater force. Can also argue it with wider disk must require more power, and since power and torque are related by the simple formula, more power means more torque and if there is more torque on the disk the only way that can occur is from a greater cutting force. This site says 'thinner ones will put far less strain on your machine, create less sparks and give a quicker and cleaner cut', which is basically the same thing:

http://www.ultimatehandyman.co.uk/Me...ting_metal.htm

Could probably find a better reference... but not now.