Fully Inserted Screw

You have to know some mechanical basic to resolve this problem, especially the basic of threading.

First of all, we have to ignore the dummy information about the hole depth. This information aren't help you to solve the problem except to confirm that the screw fully enter in the hole.

We have to find the pitch of this screw who is described like this:

"Each time that the screw's body rotates one turn (360°), it has advanced axially by the width of one ridge". This mean that each time the screw make one full turn, it enter in the hole the width of the pitch.

See the picture for details.

We have to look in the number of our 5/8"-18 Unified Thread Standard screw to find the pitch. The 18 in this number mean 18 TPI (threads per inch) . We have to divide 1 inch by the number of thread in it to find the pitch with this information : $\frac{1}{18}$ = 0.05556" per turn

From here, we have two possiblities:

whether we convert the pitch that we just find in metric or whether we convert the total length of the screw in imperial.

• Pitch convert in metric : $0.05556 \times 25.4$ = 1.4112mm per turn
• Screw length convert in inches : $\frac{48}{25.4}$ = 1.889"

The last step will give us the answer:

I want to know how many turn the screw will make to fully enter the hole. So I have to divide the lenght of the screw by the pitch width.

• in mm : $\frac{48}{1.4112}$ = 34
• in inches : $\frac{1.889}{0.05556}$ = 34

You can also multiply the 18 TPI by the length of the screw in inches : $18 \times 1.889$ = 34

the screw can do 34 turns before being fully inserted.