What max size/weight of 18" minus

[MachineEngr]

Big rock question: What are the max allowable dimensions of an 18" minus rock/gravel? Also anybody know what agency (if any) defines that standard?

Thanks

 

[MJR2]

Minus 18 inch rock means it was passed over a grizzly or thru a chrusher having a setting of 18 inches. There is usually little control in the other two dimensions. Depending on the nature of the rock two or maybe three times bigger should be planned on.

The weight will depend on the ore.

Mike