Variation in Bit Construction

Mouthpiece variations common to Snaffles and Curbs
Most bits are made of steel, iron, or aluminum. Some have mouthpieces made of or inlayed with copper, as one school of thought suggests that combining copper with steel or iron enhances salivation. Some mouthpieces are covered with rubber. Curb bit shanks and snaffle rings may be flattened or round and engraved or inlayed with precious metals (silver or gold) for aesthetic value.

Pressure is directed to specific pressure points by variations in the mouthpiece design. Mouthpiece diameter may be tapered to the center and typically varies from 5/16 inch to 3/4 inch, although there are smaller and larger sizes. The smaller the diameter of the mouthpiece, the smaller the contact in the horse's mouth. And the smaller the contact area, the more intense the pressure a horse feels from a given amount of pressure from the reins. Most mouthpieces are smooth and rounded. Some mouthpieces are twisted, rolled, or flattened to cause variations in intensity of pressure.