We have lines from old gas light fixtures poking through a tin ceiling in our parlor floor, and I was hoping to cut them down, thread the ends, and use a bolt to secure the base of a new light fixture ...

The strength of some internal threads is more sensitive to tap diameter than previously thought. • Cold-formed threads are no stronger than cut threads when holes are correctly sized. • Cut threads ...

Twist drills do not make accurately sized or good finish holes; a reamer of some type is often used to cut the final size and finish. A reamer will not make the original hole; it will only enlarge a ...