The trapezoidal thread is analogous to your acme thread, other than which the thread angle is three hundred. It is made in metric Proportions; that's why it really is known as "metric lead screw" or "metric acme screw." For details with regard to the bit, essential or Phillips stage size https://typesofporch71470.blogsidea.com/35617350/5-essential-elements-for-lead-screw-thread