Round turning insert sizeschart

The hand of the thread can be easily determined by visual inspection. Simply compare your screw threads with the right hand and left-hand threads illustrated in Figure 48.

Round turning insert sizespdf

In most cases, increasing the number of starts is preferable to increasing the pitch because larger pitches reduce the minor diameter. A small minor diameter decreases the screw stiffness and makes it more difficult to tap nuts because of the likelihood of the tap breaking during tapping. Also, for the same lead, increasing the number of starts actually increases the thread contact area when compared to a thread with the same lead but using fewer starts and a coarser pitch.

However, a number of thread series including Roton’s Hi – lead®, Torqspline® Lead Screw, and Ball Screw series screw threads may have from 2 to 20 starts or more.

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Close examination of the thread will reveal the number of starts (Figure 49). Simply place a pencil or marker pen in the thread groove and rotate the thread one revolution.