Thread Restrict or pitch diameter limit is a standard employed for classifying the tolerance from the thread pitch diameter for taps. For imperial, H or L restrictions are utilised which designate the amount of models of 0.0005 inch above or undersized the pitch diameter is from its essential worth, respectively. https://types-of-geodesic-dome48147.blogdeazar.com/29508684/5-essential-elements-for-lead-screw-thread-type