Definition of 'Cavity Back' Iron in Golf

"Cavity back" — as in "cavity back iron" — is a golf term that refers to a design feature in irons that produces increased perimeter weighting, thereby making irons that have cavity backs more forgiving on mishit shots. To put it another way, a cavity back is intended to make the iron easier to hit for a wider range of golfing abilities.

Picture the clubhead of an iron, made of metal. A cavity back iron is one in which the back of the clubhead has been hollowed out, or scooped out (creating a cavity, hence the name), as in the photo on this page. An iron clubhead where that hollowing out is not done — where the back of the clubhead is left full — is called a muscleback.

The Purpose of a Cavity Back in Irons

Creating such a cavity in the back of an iron head removes weight from behind the center of the clubface, meaning more of the clubhead's mass is around the perimeter, or edges, of the clubhead. (That's what "perimeter weighting," another common golf equipment term, refers to.)

This adjustment to the club's physical appearance and weighting characteristics also adjusts the physics of impact between clubface and golf ball. The intended result is an iron that is easier to hit for a wider range of golfers (larger sweet spot, higher moment of inertia, more forgiveness).

Cavity back irons don't eliminate mishits. But their design is intended to minimize the severity of mishits. Golfers playing irons with cavity backs might still slice and hook, for example, but — relative to shots struck with non-cavity back irons — those hooks and slices will be somewhat lessened by the cavity back irons.

More Facts About Cavity Backs

Cavity back irons can be manufactured through the forging process, and some are, but most are made through the casting process. (The difference between forged and cast irons is probably less than you've been led to believe, however.)

Cavity back irons fall into the category of "game improvement clubs" and are preferred by mid- and high-handicap golfers. But many low-handicappers and even touring pros use cavity backs, too, for their forgiving properties. Cavity back irons are far, far more common in modern golf than muscleback irons.

The term is frequently spelled as one word — cavityback — and either spelling is acceptable.