Activities Sports & Athletics Callaway X-18 Irons: Features, Specs and Buying Used Share PINTEREST Email Print Callaway Golf Sports & Athletics Golf Gear Basics History Golf Courses Famous Golfers Golf Tournaments Baseball Basketball Bicycling Billiards Bodybuilding Bowling Boxing Car Racing Cheerleading Cricket Extreme Sports Football Gymnastics Ice Hockey Martial Arts Professional Wrestling Skateboarding Skating Paintball Soccer Swimming & Diving Table Tennis Tennis Track & Field Volleyball Other Activities Learn More By Brent Kelley Brent Kelley is an award-winning sports journalist and golf expert with over 30 years in print and online journalism. our editorial process Brent Kelley Updated April 13, 2019 Callaway Golf introduced two new sets of irons in late 2004, which began turning up in golfers' hands in early 2005: The X-18 and X-18 Pro Series irons. The X-18 irons replaced the previous generation X-16 irons in the Callaway lineup and were themselves later superseded by the X-20 irons. Buying Callaway X-18 Irons Used The X-18 irons can still be found used in golf shops that deal in used clubs, and also online. Callaway Golf itself often has X-18 sets and individual irons listed on Amazo. Check this link to see what's available now: The manufacturer also lists available X-18s on CallawayPreOwned.com. And you can check trade-in value and resale value of X-18s with the PGA Value Guide. Now, here's a look back at what was being said about the Callaway X-18 irons when they first debuted, in the form of our original article from that time: X-18 the Next Step in Callaway Irons Dec. 21, 2004 - The X-18 and X-18 Pro Series irons are the newest irons in Callaway's X-Series line. "With each iron containing years of knowledge built into a new, sleek package, both X-18 models incorporate the player-trusted and Tour-tested performance features" Callaway is known for, the company said in a news releasing announcing the new product. The X-18 and X-18 Pro Series irons are the successors to their X-16 counterparts. Among the X-18 features: Extreme Notch Weighting: A proprietary - and visible - feature that raises each iron's Moment of Inertia (MOI) for increased stability and better results on off-center hits.S2H2: S2H2 stands for "Short Straight Hollow Hosel," and it's been a staple of Callaway irons for more than 15 years. The S2H2 systems allow weight to be moved lower and to the perimeter area of the clubhead. This increases forgiveness and aids the golfer in getting the ball airborne.Tru-Bore: An integral element of the S2H2 design is Tru-Bore Technology, which extends the shaft tip completely through the clubhead to the sole for greater feel and superior control.Variable Face Thickness: VFT, or Variable Face Thickness, is a face design technology through which Callaway is able to raise or lower the center of gravity for optimum trajectory with each iron in the set. The result is a higher launch angle in the long irons and better trajectory height control in the short irons and wedges. The X-18 Irons also feature a standard progressive offset throughout the set. Standard X-18 Irons are available in 2-iron through 9-iron plus Pitch (46 degrees), Approach (51 degrees), Sand (56 degrees) and Lob (60 degrees) wedges. The standard steel shaft is the Constant Weight Uniflex by True Temper, and graphite shaft options include System 55i (light flex), System 75i (regular flex), System 85i (stiff flex), and Gems(TM) 45i (ladies flex). X-18 Pro Series Irons come in the same set and wedge configuration and feature True Temper Dynamic Gold steel shafts standard (in R300, S300, and X100 flexes). The standard graphite shaft is the RCH Pro Series M-75i and comes in regular, stiff and X-stiff flexes. X-18 Irons have an MSRP of $110 per club for steel-shafted models and $140 per club for graphite-shafted models. The irons will begin shipping to retailers on Jan. 1, 2005.