Question

A threaded nut of M 16, ISO metric type, having 2 mm pitch with a pitch diameter 14.701 mm is to be checked for its pitch diameter using two or three number of balls of rollers of the following sizes

• A. $\text{Balls of 2 mm}\phi$
• B. $\text{Rollers of 2 mm}\phi$
• C. $\text{Rollers of 1.155 mm}\phi$
• D. $\text{Balls of 1.155 mm}\phi$

Answer 1

The correct option is C $\text{Rollers of 1.155 mm}\phi$

$\text{Given Metric thread M 16}$

$\text{In case of threads always rollers (wires) are used.}$

$\text{Pitch: P=2 mm}$

$\text{Pitch diameter = 14.701 mm}$

$\text{In case of Metric thread}2\theta ={60}^{\circ }$

$\Rightarrow \theta ={30}^{\circ }$

$\text{For a best size wire}$

$d_w=\frac{P}{2}sec\theta =\frac{2}{2}sec{30}^{\circ }=1.155mm$