387 Каталог KORLOY 2020 Инструмент и оснастка для станков по металлу Стр.D3

Каталог KORLOY 2020 Инструмент для станков по металлу Стр. D3 0387 Lab2u

Technical Information for Threading O Special features External thread A thread on the external surface of a cylinder screw or cone Depth of thread The distance between the crest and root measured from normal to the axis Pitch The distance between the corresponding points on adjacent thread forms measured parallel to the axis. This distance can be defined in millimeters or by the tpi (threads per inch), which is the reciprocal of the pitch Nominal diameter The diameter of which the diameter limits are derived by the application of deviation allowances and tolerances External Internal thread A thread on the internal surface of a cylinder or cone Major diameter The largest diameter of a screw thread Pitch diameter On a straight thread, the diameter of an imaginary cylinder, the surface of which cuts the thread forms where the width of the thread and groove are equal Minor diameter The smallest diameter of a screw thread Helix angle For a straight thread, where the lead of the thread and the pitch diameter circle circumference form a right angled triangle, the helix angle is the angle opposite of the lead Straight thread A thread formed on a cylinder Taper thread A thread formed on a cone Left handed thread A thread which, when viewed axially, winds in a counter clockwise and receding direction. All left handed threads are designated LH Right handed thread A thread which, when viewed axially winds in a clockwise and receding direction. Threads are always right handed unless they are specified The helix angle ((3) \ Helix angle(p) Lead (L) it X Pitch diamiter (D) For a straight thread, where the lead of the thread and the pitch diameter circle circumference form a right angled triangle, the helix angle is the angle opposite of the lead O Machining a multi-start thread A thread in which the lead is an integral multiple, greater than one, of the pitch. A multi-start thread permits a more rapid advance without a coarser (larger) thread form First start machined Second start machined Third start machined (Final, 3 starts thread) Pitch Lead O Insert profile style Partial profile Full profile Full profile for fine pitches Semifull The V partial profile insert cuts without topping the outer diameter of the thread. The same insert can be used for a range of different thread pitches which have a common thread angle The full profile insert will form a complete thread profile including the crest. For every thread pitch and standard, a separate insert is required The full profile for Fine Pitches will form a complete thread The topping of the outer diameter is generated by second tooth The Semi profile insert will form a complete thread including crest radius but without topping the outer diameter Mainly used for trapezoidal profiles J. Threading 3