The ratio of the threads per inch of the thread being cut and the threads per inch of the lead screw is the same as the ratio of the speeds of the spindle and the lead screw. For example, if the lead screw and spindle turn at the same speed, the number of threads per inch of the thread being cut is the same as the number of threads per inch of the lead sacrew. If the spindle turns twice as fast as the lead screw, the number of threads per inch of the thread being cut is twice the number of threads per inch of the lead screw.