This A$-$Frame bracket is to be mounted to a plate found in a lab with a bolt and nut $(2$ places$)$ and is to support a weight of $40$ kN $.$ A course thread type is to be used.

The distance between the mounting holes is $610$ mm and the vertical distance from the mounting holes to the center of the attachment point is $457$ mm $.$ The attachment point is in the center of the frame.

a$.$ The minimum bolt size that can be used to mount this bracket.

b$.$ The required tightening torque.

c$.$ The least number of threads that must be engaged with the nut to ensure no thread shearing $($stripping$)$ occurs between the bolt and nut.