232, include corner-irons, straight plates and panel-irons.

These are made of either iron or brass and are used in fastening legs to the floor, in stiffening joints, affixing tops, etc.
_Dowel-rods._ Dowel-rods are cylindrical rods, from 3/16" to 1" in diameter, and 36", 42", and 48" long.

They are commonly made of birch or maple, but maple is more satisfactory as it shrinks less and is stronger than birch.
Dowels are used as pins for joining boards edge to edge, and as a substitute for mortise-and-tenon joints.
[Illustration: Fig.231.

Machine-screws.

a.