Tip #90
How to Drill Holes for Screws in Hardwood
Right Click here to download a printer friendly version of Tip-
Pg. 1-3 (906 KB)
Help with Downloading PDF Files

Description:

Screws may be readily set into hardwood by drilling a pilot hole having a diameter equal to that of the root of the screw and a clearance hole equal to that of the shank or gauge of the screw.

Fig. 1 Click image for larger view.

Screw holes in hardwoods are countersunk to bring screw head flush with surface when the screw is driven. The screw head can be covered with a wood plug, when screw is driven, if the hole is counterbored.

Fig. 2Click image for larger view.

Dimensions of holes for accommodating screw heads vary with the type of screw used: Common types are shown in diagram.

Fig. 3 Click image for larger view.

All three heads are either slotted or recessed.

Use:
Screw holes are drilled in hardwood so that the screws can be readily driven at the correct angle to hold the material with maximum strength. In addition, drilled holes reduce the probability of damage to the screws and to the material joined.

Continue to Operations