Irons: why a 7-iron is not always a 7-iron.

One set, published as an example

The governing bodies do not define standard lofts and set no limit on loft, so every iron set is the maker's own design. PING's published specifications for its G440 irons show how a modern set is spaced. PING says these are design figures that may vary within manufacturing tolerances.

PING also offers 52 and 56 degree wedges to continue the set.

Strong and weak lofts

The same G440 irons are offered in two other loft schemes: a stronger "Power Spec" and a weaker "Retro Spec". The 7-iron, for example, is 27.5 degrees in Power Spec and 31 degrees in Retro Spec, against 29 degrees standard. So a 7-iron from one maker, or even one option within a model, can carry several degrees more or less loft than another. GolfMagic reports wedge designer Bob Vokey's view that pitching wedge lofts have moved from about 51 degrees to about 45 to 47, while sand wedges stayed near 56, which in his view is why the gap wedge exists.

Why lofts have changed is debated in the trade press, but the sources we found for both sides were only available to us as search summaries, so we have not set out the argument here. The practical point is simple: compare irons by their published lofts and by the distances you actually hit them, not by the number on the sole.

Lie angle and colour codes

Lie angle describes how upright the club sits, and fitters aim for a lie at which the sole meets the ground evenly. PING sorts lie angle by a colour code, and publishes its standard lie angles for the Black code at standard length; the 7-iron above is 62 degrees on that basis.

Lie can also be checked dynamically. CaddieHQ describes putting impact tape on the sole, hitting shots, and then bending the club flatter or more upright until the sole meets the ground evenly. A US patent on a trial fitting club describes the lie-board method, where the golfer hits off a hard board and the mark on the sole shows whether the lie is right. AmateurGolf.com says iron fittings typically begin with a 7-iron to set carry distance and flight. See club fitting.

What the Equipment Rules say about iron heads

• Shape. At address, the heel-to-toe length must be greater than the face-to-back length. The head must be generally plain, rigid and functional, with only one striking face.
• Face hardness. At least 75 on the Shore D scale.
• Face roughness. In the impact area, no rougher than decorative sandblasting (180 micro-inches) or fine milling (a crest-to-trough depth of 0.001 inch).
• Length. Between 18 and 48 inches, measured with the sole against a 60-degree plane.

Grooves

For new club models made on or after 1 January 2010, Part 2 limits groove width to 0.035 inch, depth to 0.020 inch, and requires spacing of at least three times the width and at least 0.075 inch. It also caps groove cross-sectional area relative to groove pitch for clubs other than driving clubs, and, on clubs of 25 degrees of loft or more, requires a plain cross-section with an edge radius of 0.010 to 0.020 inch. Grooves must be straight and parallel, with no sharp edges or raised lips.

These 2010 specifications do not currently apply to every golfer. On 25 January 2024 the R&A said that, after review, they would stay in effect only through Model Local Rule G-2, which is recommended only for competitions of highly skilled players. G-2 applies only when a Committee adopts it. Any future decision to apply the 2010 specifications to all golfers would not take effect until at least four years after it is announced. The full history is on the conforming equipment page.

Clubs whose face markings are purposely altered, for example by re-grooving, are held to the 2010 specifications too.

Nothing on this page says a particular iron set conforms. If you play in a competition that uses Model Local Rule G-2, check the R&A's equipment database for your model.