From Golf Magazine (December, 2011)
Titleist’s latest multimaterial AP1 and AP2 irons are designed to look small and play big. The reengineered clubheads have a higher moment of inertia (MOI), or resistance to twisting, than their predecessors. The by-product is greater forgiveness, more consistent ball speeds across the face (for improved distance control) and tighter dispersion on off-center hits. Both models also have “low inertia” around the shaft axis (as determined by blade length and center-of-gravity position). This simply means that it’s easier to square up the clubface at impact.
The AP2 712 irons (“712” stands for the 2012 model year) are made of forged 1025 carbon steel and offer a high degree of “workability,” a quality that better players covet. These third-generation sticks also feature more weight concentrated in the heel and toe than the current AP2 710, which equates to a 7 percent higher MOI. In fact, these game-enhancing irons are nearly as forgiving as the original game-improvement AP1. The secret: using a thin stainless steel “cradle” along the back of the club in combination with tungsten slugs in the heel and toe that total 50 grams. (The current AP2 has a “tungsten-nickel box” that extends the entire length of the blade.)
The larger AP1 712, made of cast stainless steel, provides more forgiveness but less “maneuverability” than the AP2. In this case, discretionary mass is shifted from the topline (1 gram), center back (5 grams) and stainless steel sole plate (28 grams) to a heavy tungsten toe weight. The result? Long irons have a 4 to 7 percent higher MOI than the AP1 710, while short irons have the same inertia as before.
AP2: $1,099, steel; AP1: $799, steel or $999, graphite