ME 319 Chapter Notes - Chapter 8: Trapezoidal Thread Forms, Jackscrew, Thread Angle

• School: Cal Poly Pomona
• Department: Mechanical Engineering
• Course: ME 319
• Professor: Perham Piroozan

Document Summary

The major diameter d is the largest diameter of a screw thread. The minor (or root) diameter dr is the smallest diameter of a screw thread. The pitch diameter dp is a theoretical diameter between the major and minor diameters. The lead l, not shown, is the distance the nut moves parallel to the screw axis when the nut is given one turn. For a single thread, the lead is the same as the pitch. A multiple-threaded product is one having two or more threads cut beside each other (imagine two or more strings wound side by side around a pencil). Standardized products such as screws, bolts, and nuts all have single threads; a double-threaded screw has a lead equal to twice the pitch, a triple-threaded screw has a lead equal to 3 times the pitch, and so on. Basic profile for metric m and mj threads (cid:1856) = (cid:1865)(cid:1862)(cid:1867)(cid:1870) (cid:1856)(cid:1861)(cid:1865)(cid:1857)(cid:1872)(cid:1857)(cid:1870) (cid:1856)=(cid:1865)(cid:1861)(cid:1866)(cid:1867)(cid:1870) (cid:1856)(cid:1861)(cid:1865)(cid:1857)(cid:1872)(cid:1857)(cid:1870)