The 1972 Chouinard Catalog has the following useful product information about pitons.
Masterpieces in design, having fair lines and functional shapes, these angles typify the high qualities of beauty in the Chouinard line of pitons. The angle pitons have inherently exceptional holding power; yet when not overdriven they are easy to remove, and retain long service life. Because this size crack is frequently encountered, the ¾” angle has become the standard angle piton of the American climber. The 1”, 1-1/4”, and 1-1/2” angles are consecutively lager sizes required for wide-angle cracks. The latter two are riveted closed for greater strength, holding power, ease of removal and endurance. All the angles are made of aircraft quality alloy steel, and heat-treated for optimum toughness.
Alloy steel angles are more destructive to the cracks than any other piton. Because of the tremendous stiffness and hardness of the alloy steel, in a short time the thin edges of their blades can cut grooves in even the toughest rock. However, these sized cracks are the ones most suited for chocks. We urge the use of chocks whenever possible.
The young Yvon Chouinard purchased a forge in 1956 and started fabricating chrome moly steel pitons using a Diamond C logo, originally selling them from his truck in Yosemite Valley to support his own climbing and surfing lifestyle. Chouinard went on to found the Great Pacific Iron Works in Ventura, CA. and later the very successful Patagonia. Chouinard climbing equipment developed a worldwide reputation for quality.
