Once upon a time, there were simply… irons. We now refer to these vestiges of history as “blade” irons—forged from thin blocks of carbon steel that were shaped by hand and/or machine, then plated with chrome. If you did not hit the ball squarely with them, you felt a distinctly unpleasant vibration that was generally followed by a bad shot and, even worse, four-letter words. But irons have evolved, and the choices are multiplying.
Strictly speaking, it may be wrong to call any modern iron a “blade.” Original blades were very thin and hard to hit, but along the way clubmakers learned that the head could be shaped to put more metal low and behind the hitting area for easier shotmaking. Those blades gained the nickname “muscle backs,” and were an instant success. These blades were also more expensive, as the forging and shaping processes were time- and labor-intensive.
Golf manufacturers not only sought cheaper ways to produce irons, but also ways to make them easier to hit. When Ping successfully produced irons using a casting process—where molten metal could be formed in a mold—it found an economical and new method of shaping irons. Cavity backs carried the muscle back a step further, allowing weight to be moved to the base or edges of the head with equal ease.
Cavity-back design allowed manufacturers to create an iron that did not require a perfect strike to make an acceptable shot. This “forgiveness,” created by moving more weight to the periphery of the iron head, meant bad shots were neither as far offline nor suffered as much of a distance penalty as the old blades. In addition, by moving more weight to the sole of the club, cavity backs made it easier to get the ball off the ground. This meant an average player could use less loft and, thus, hit the ball farther. The term “game improvement clubs” became the most popular name for cavity-back designs.
Blades, however, retained certain advantages. A well-hit blade shot provided more feedback to good players, allowing them to better gauge how well they were striking the ball. Blades also allowed a player to shape shots better than cavity-back designs, which became more popular in part because the ball naturally went straighter. Blades gained the nickname “player’s clubs,” because the best players preferred the extra control and feedback. In addition, blades often had more graceful lines than the sometimes chunky cavity backs.
The Lines Are Blurring
These differences, however, are no longer as clear as they once were. Forged blades are now made with shallow cavities to improve accuracy, and cavity backs are being made that provide increased feel and maneuverability. In fact, when manufacturers such as Mizuno unveil new club designs, it can be difficult to see any major difference between their player’s clubs and their game-improvement designs. The once-clear divide between blades and cavity backs is vanishing as the two join and form new easier-to-hit irons.