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Such an appropriately sized drill is called a tap drill for that size of thread, because it is a correct drill to be followed by the tap. Many thread sizes have several possible tap drills, because they yield threads of varying thread depth between 50% and 100%. Usually thread depths of 60% to 75% are desired.
The thread depth is 0.54125 × pitch. The outermost 1 ⁄ 8 and the innermost 1 ⁄ 4 of the height H of the V-shape are cut off from the profile. The relationship between the height H and the pitch P is found using the following equation where θ is half the included angle of the thread, in this case 30°: [ 3 ]
The Unified Thread Standard (UTS) defines a standard thread form and series—along with allowances, tolerances, and designations—for screw threads commonly used in the United States and Canada. It is the main standard for bolts, nuts, and a wide variety of other threaded fasteners used in these countries.
A perfectly sharp 60° V-thread will have a depth of thread ("height" from root to crest) equal to 0.866 of the pitch. This fact is intrinsic to the geometry of an equilateral triangle — a direct result of the basic trigonometric functions. It is independent of measurement units (inch vs mm). However, UTS and ISO threads are not sharp threads.
Die nut s, also known as rethreading dies, are dies made for cleaning up damaged threads, [9] have no split for resizing and are made from a hexagonal bar so that a wrench may be used to turn them. The process of repairing damaged threads is referred to as "chasing." Rethreading dies cannot be used to cut new threads as they lack chip forming ...
The price and availability of particular size bits does not change uniformly across the size range. Bits at size increments of 1 mm are most commonly available, and lowest price. Sets of bits in 1 mm increments might be found on a market stall. In 0.5 mm increments, any hardware store. In 0.1 mm increments, any engineers' store.
The full battery designation identifies not only the size, shape and terminal layout of the battery but also the chemistry (and therefore the voltage per cell) and the number of cells in the battery. For example, a CR123 battery is always LiMnO 2 ('Lithium') chemistry, in addition to its unique size.
Thus, if the thread pitch is p, the height of the fundamental triangle is H = p/(2tanΘ) = 0.96049106p. However, the top and bottom 1 ⁄ 6 of each of these triangles is cut off, so the actual depth of thread (the difference between major and minor diameters) is 2 ⁄ 3 of that value, or h = p/(3tanΘ) = 0.64032738p.