Final answer:
It is true that a 6-point box-end wrench is better suited for extremely tight bolts due to its secure grip. Adding a pipe for leverage increases torque but can be risky. Option A is correct.
Step-by-step explanation:
The statement that a 6-point box-end wrench should be used when a bolt head or nut is extremely tight is True. The design of a 6-point wrench allows it to grip the flat sides of a nut or bolt head more securely, reducing the likelihood of slipping off or rounding the corners of the fastener when significant force is applied.
Mechanics enhance the torque by using a length of pipe over the handle of a wrench, which effectively increases the leverage and the resulting torque that can be applied to the fastener. This method improves the mechanical advantage, but as indicated, it also poses a risk of breaking the fastener due to the increased torque.
To understand how this works, consider the concept of torque, which is the product of force and the distance from the pivot point (in this case, the center of the nut or bolt). By adding a longer handle, you're increasing the distance, which allows the same amount of force to produce more torque. This is similar to using a longer wrench.