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Iron (golf)
Encyclopedia
An iron is a type of club
used in the sport of golf
to propel the ball
towards the hole. They are so-called because historically the clubhead was generally made from iron
. Whilst the vast majority of modern irons are still made from iron, it is almost always its stronger and more durable alloy, steel
.
There are three main components to an iron, the club head, the shaft
and the grip
. The face of the clubhead, used to strike the ball, is scored with grooves designed to impart spin, enabling the skilled player to more easily control the ball.
A standard set of 14 golf clubs will contain many irons, which are customarily differentiated by the angle of loft on the clubface, although they will also vary in clubhead size, shaft length, and hence lie angle. Irons are usually numbered, with the 1 iron having the lowest loft, smallest clubhead and longest shaft, through to the 9 iron and wedges
, which have the greatest loft, largest heads and shortest shafts. These different characteristics allow different irons to be used from a variety of situations, from the teeing ground
, fairway, rough, or from within hazards
, such as bunkers.
from a flat piece of metal, which produced a thin clubhead that resembled a blade
. Modern investment casting
processes enabled manufacturers to easily mass produce clubs with consistent properties. This manufacturing process was first used by PING
, and also made it possible to take weight out of the back of the clubhead and distribute it around the perimeter. These perimeter weighted, or cavity back, irons made it much easier to achieve consistent results even when striking the ball outside the "sweet spot", when compared with traditional bladed, or muscle back, irons.
Although most irons are now produced by investment casting, many high end, particularly muscle back, irons are still produced by forging, as it is believed that the resulting club has an improved "feel". Manufacturers sometimes try to combine the characteristics of both muscle and cavity backed irons, which has resulted in terminology such as cut-muscle, or split-cavity.
There are also many hybrid
clubs, so-called because they combine some of the characteristics of irons and woods
, that closely resemble standard irons. Indeed, many sets of clubs, especially those marketed for beginners, now include hybrids to replace the more traditional 3 and 4 irons.
Perceived advantages of muscle backs are that, when hit correctly, they provide greater distance than cavity backs, and much improved feel, although this is most likely due to the forging process by which they are usually made.
The perimeter weighting increases the size of the sweetspot and the moment of inertia
of the clubhead, which reduces twisting when the ball is struck off-center, allowing such shots to lose less distance and accuracy when compared with a muscle back iron. More weight is often put into the sole of the clubhead, which lowers the center of gravity and increases the launch angle of the ball.
The forgiving nature of cavity backs combined with the ease with which they enable the average golfer to get the ball airborne, make them the most popular design of iron with amateurs.
The shaft length of an iron decreases as the iron's number increases; therefore the iron number is disproportional to its length. This reduced length means that a clubhead of the same mass traveling at the same angular velocity (degrees per second, as swung by a golfer) has lower momentum because the clubhead's speed is slower. To combat this, higher-numbered iron clubheads are heavier than lower-numbered iron heads; there is generally a 4oz increase in mass between one clubhead and the next higher number.
Over the years, groove technology has changed the playability of irons. For the past 80 years, little has changed about grooves. However, a new rule by the USGA and the R&A has changed the way that grooves are to be made starting in 2010. In general, the deeper the groove, the more grass can be dispersed behind the ball at impact. This allows control over the amount of spin, which is crucial to flight characteristics of the shot as well as how well received the ball is on the green. The less that is between the ball and the club at impact, the more spin that will be produced which increases the flight trajectory and allows stopping quicker upon hitting the green. Better players benefit the most from deep, sharp grooves as the more clubhead speed is generated, the more spin the player is able to introduce. By forcing manufacturers to lessen the depth and cut on the grooves, the new rules will penalize shots from longer grass slightly more and put a premium on hitting the fairway.
A stroke in which the ball comes directly off the hosel is known as a "shank", and the ball will usually veer off almost at right angles to the intended target line.
Although graphite shafts, made from composite materials such as carbon fiber
, are now standard in woods, especially drivers, shafts for irons are still most often made from steel, which has lower torque than graphite, allowing less clubhead twisting, which gives better accuracy. Graphite shafts are not uncommon for numbered irons however, as the increased distance conferred by the shaft is advantageous to many players, especially shorter hitters such as ladies and seniors. Wedges virtually always have steel shafts as the accuracy and consistency is of primary importance.
The higher the number of the iron, the shorter its shaft will be, allowing the player a more controlled and consistent swing. The resulting reduction in clubhead velocity is overcome by an increase in clubhead mass.
By the rules of golf
, all iron grips must have a circular cross-section. They may taper from thick to thin along their length (and virtually all do), but are not allowed to have any waisting (a thinner section of the grip surrounded by thicker sections above and below it) or bulges (thicker sections of the grip surrounded by thinner sections). Minor variations in surface texture (such as the natural variation of a "wrap"-style grip) are not counted unless significant.
did make a 0 iron for John Daly
. Often called a butter knife because of its looks, the 1 iron is commonly regarded as the hardest club in the bag to hit, and is now virtually obsolete. Lee Trevino
is famously quoted, after he had almost been struck by lightning at the 1975 Western Open
, that if he were out on the course and it began to storm again he would take out his 1 iron and point it to the sky, "because not even God can hit a 1 iron."
The 2 to 9 irons traditionally made up a standard set of irons, although with technological advances, changes to specifications and preferences of the average golfer, the 2 iron is now generally omitted, and a pitching wedge
included. A modern matched set of irons will often also have a sand wedge. The 2 iron's place in the bag is often taken by a third wedge
. Increasingly, with the introduction of hybrid clubs that are easier to hit than the longer irons, the 3 and 4 irons are also omitted.
Due to the average golfer's desire to hit the ball farther, the loft on modern irons is much less than that on irons from even the late 20th century. For example a modern 9 iron has comparable loft to a 7 iron from the 1990s. Manufacturers have been able to reduce loft without compromising usability, by moving weight into the sole of the clubhead, thereby lowering the center of gravity
and enabling the ball to be launched on a higher trajectory than would otherwise be the case.
Wedges are used mostly for approach shots to the putting green, getting the ball out of tough situations, and to escape from hazards. They are designed to produce a high, short trajectory with a high degree of spin, all of which cuts down on the distance the ball will roll after landing. Most golfers will generally have at least two wedges, traditionally a pitching wedge and a sand wedge, with a lob wedge or a gap wedge commonly being added to provide additional options. Wedges are usually identified by their loft (56°, 62°, etc.) or letter denoting their function (PW, GW, SW, LW, etc.).
Given the choices available to the modern golfer, the traditional pair of pitching wedge and sand iron is starting to become less common as players opt for a selection wedges with an array of different lofts and bounce angles. For example, a player may pick two gap wedges, one with low bounce but greater loft than a pitching wedge, and the other with similar bounce but less loft than a sand wedge, then add a lob wedge and forgo both of the traditional wedges.
The following table provides a guide to the typical specifications of irons through to the mid 1990s.
Golf club (equipment)
A golf club is used to hit a golf ball in a game of golf. Each club is composed of a shaft with a grip and a clubhead. Woods are mainly used for long-distance fairway or tee shots; irons, the most versatile class, are used for a variety of shots; Hybrids that combine design elements of woods and...
used in the sport of golf
Golf
Golf is a precision club and ball sport, in which competing players use many types of clubs to hit balls into a series of holes on a golf course using the fewest number of strokes....
to propel the ball
Golf ball
A golf ball is a ball designed to be used in the game of golf.Under the Rules of Golf, a golf ball weighs no more than 1.620 oz , has a diameter not less than 1.680 in , and performs within specified velocity, distance, and symmetry limits...
towards the hole. They are so-called because historically the clubhead was generally made from iron
Iron
Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...
. Whilst the vast majority of modern irons are still made from iron, it is almost always its stronger and more durable alloy, steel
Steel
Steel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, and tungsten...
.
There are three main components to an iron, the club head, the shaft
Shaft (golf)
The shaft of a golf club is the long, tapered tube - generally made of steel or carbon fiber composite - which connects the golfer’s hands to the club head...
and the grip
Handle (grip)
A handle is a part of, or attachment to, an object that can be moved or used by hand. The design of each type of handle involves substantial ergonomic issues, even where these are dealt with intuitively or by following tradition...
. The face of the clubhead, used to strike the ball, is scored with grooves designed to impart spin, enabling the skilled player to more easily control the ball.
A standard set of 14 golf clubs will contain many irons, which are customarily differentiated by the angle of loft on the clubface, although they will also vary in clubhead size, shaft length, and hence lie angle. Irons are usually numbered, with the 1 iron having the lowest loft, smallest clubhead and longest shaft, through to the 9 iron and wedges
Wedge (golf)
In the sport of golf, a wedge is a subset of the iron family of golf clubs designed for special use situations. Wedges are designed with modified soles designed to aid in shots through the rough or sand. Wedges have the greatest loft of all of the golf clubs, enabling the ability to produce spin...
, which have the greatest loft, largest heads and shortest shafts. These different characteristics allow different irons to be used from a variety of situations, from the teeing ground
Teeing ground
In golf, the teeing ground is the area at the beginning of a hole from which the player's first stroke is taken. When referring to the area, the terms "tee", "tee box", and "teeing ground" are often used interchangeably....
, fairway, rough, or from within hazards
Hazard (golf)
A hazard is an area of a golf course in the sport of golf which provides a difficult obstacle. which may be of three types: water hazards such as lakes and rivers; man-made hazards such as bunkers; and natural hazards such as dense vegetation. Special rules apply to playing balls that fall in a...
, such as bunkers.
Design and manufacture
Historically all irons were forgedForging
Forging is a manufacturing process involving the shaping of metal using localized compressive forces. Forging is often classified according to the temperature at which it is performed: '"cold," "warm," or "hot" forging. Forged parts can range in weight from less than a kilogram to 580 metric tons...
from a flat piece of metal, which produced a thin clubhead that resembled a blade
Blade
A blade is that portion of a tool, weapon, or machine with a cutting edge and/or a pointed tip that is designed to cut and/or puncture, stab, slash, chop, slice, thrust, or scrape animate or inanimate surfaces or materials...
. Modern investment casting
Investment casting
Investment casting is an industrial process based on and also called lost-wax casting, one of the oldest known metal-forming techniques. From 5,000 years ago, when beeswax formed the pattern, to today’s high-technology waxes, refractory materials and specialist alloys, the castings allow the...
processes enabled manufacturers to easily mass produce clubs with consistent properties. This manufacturing process was first used by PING
Ping (golf)
PING is an American brand of high-quality golf equipment, as well as one of the largest of the remaining American manufacturers of golf clubs, based in Phoenix, Arizona, founded by Karsten Solheim, who was an engineer at the General Electric company. In 1959, he started making his own putters in...
, and also made it possible to take weight out of the back of the clubhead and distribute it around the perimeter. These perimeter weighted, or cavity back, irons made it much easier to achieve consistent results even when striking the ball outside the "sweet spot", when compared with traditional bladed, or muscle back, irons.
Although most irons are now produced by investment casting, many high end, particularly muscle back, irons are still produced by forging, as it is believed that the resulting club has an improved "feel". Manufacturers sometimes try to combine the characteristics of both muscle and cavity backed irons, which has resulted in terminology such as cut-muscle, or split-cavity.
There are also many hybrid
Hybrid (golf)
A hybrid is a type of club used in the sport of golf with a design which differs from that of irons and woods. The name "hybrid" comes from genetics to denote a mixture of two different species with desirable characteristics of both, and the term here has been generalized, combining the advantages...
clubs, so-called because they combine some of the characteristics of irons and woods
Wood (golf)
A wood is a type of club used in the sport of golf. Woods are used to hit the ball farther than any other type of golf club....
, that closely resemble standard irons. Indeed, many sets of clubs, especially those marketed for beginners, now include hybrids to replace the more traditional 3 and 4 irons.
Muscle back
A muscle back is the more traditional design and consists of a solid head with little or none of the weight being distributed around the perimeter of the head. As such they require a great deal of skill in order to hit the ball consistently because the "sweetspot" is fairly small. In addition, any shot that is struck "off-center" may be severely compromised in terms of distance and direction.Perceived advantages of muscle backs are that, when hit correctly, they provide greater distance than cavity backs, and much improved feel, although this is most likely due to the forging process by which they are usually made.
Cavity back
Cavity back, or perimeter weighted, irons are usually made by investment casting. They are so called because of the cavity created by the redistribution of the weight from the middle to the perimeter of the clubhead when compared with a traditional muscle back.The perimeter weighting increases the size of the sweetspot and the moment of inertia
Moment of inertia
In classical mechanics, moment of inertia, also called mass moment of inertia, rotational inertia, polar moment of inertia of mass, or the angular mass, is a measure of an object's resistance to changes to its rotation. It is the inertia of a rotating body with respect to its rotation...
of the clubhead, which reduces twisting when the ball is struck off-center, allowing such shots to lose less distance and accuracy when compared with a muscle back iron. More weight is often put into the sole of the clubhead, which lowers the center of gravity and increases the launch angle of the ball.
The forgiving nature of cavity backs combined with the ease with which they enable the average golfer to get the ball airborne, make them the most popular design of iron with amateurs.
Clubhead
Investment casting, while allowing for a greater range of design options, produces a very stiff and inflexible head that can be difficult to adjust for a player's desired lie and loft. Forged irons, while they allow for easier and a greater range of adjustments are limited in the designs they may be achieved.The shaft length of an iron decreases as the iron's number increases; therefore the iron number is disproportional to its length. This reduced length means that a clubhead of the same mass traveling at the same angular velocity (degrees per second, as swung by a golfer) has lower momentum because the clubhead's speed is slower. To combat this, higher-numbered iron clubheads are heavier than lower-numbered iron heads; there is generally a 4oz increase in mass between one clubhead and the next higher number.
Over the years, groove technology has changed the playability of irons. For the past 80 years, little has changed about grooves. However, a new rule by the USGA and the R&A has changed the way that grooves are to be made starting in 2010. In general, the deeper the groove, the more grass can be dispersed behind the ball at impact. This allows control over the amount of spin, which is crucial to flight characteristics of the shot as well as how well received the ball is on the green. The less that is between the ball and the club at impact, the more spin that will be produced which increases the flight trajectory and allows stopping quicker upon hitting the green. Better players benefit the most from deep, sharp grooves as the more clubhead speed is generated, the more spin the player is able to introduce. By forcing manufacturers to lessen the depth and cut on the grooves, the new rules will penalize shots from longer grass slightly more and put a premium on hitting the fairway.
Hosel
For irons, the hosel is very noticeable, forming a barrel shape on the inside face of the club and the "heel" of the sole of the club. Many modern irons have a more offset hosel, integrated into the clubhead at a lower point and further from the hitting area of the club. This, combined with the perimeter weighting of modern irons, gives a club with the lowest possible center of gravity and the highest possible usable club face.A stroke in which the ball comes directly off the hosel is known as a "shank", and the ball will usually veer off almost at right angles to the intended target line.
Shaft
The shaft is the true engine of the iron. A shaft that is perfectly suited to the individual golfer increases distance and improves accuracy, while a poorly suited shaft can lead to inconsistent, wayward shots and reduced distance.Although graphite shafts, made from composite materials such as carbon fiber
Carbon fiber
Carbon fiber, alternatively graphite fiber, carbon graphite or CF, is a material consisting of fibers about 5–10 μm in diameter and composed mostly of carbon atoms. The carbon atoms are bonded together in crystals that are more or less aligned parallel to the long axis of the fiber...
, are now standard in woods, especially drivers, shafts for irons are still most often made from steel, which has lower torque than graphite, allowing less clubhead twisting, which gives better accuracy. Graphite shafts are not uncommon for numbered irons however, as the increased distance conferred by the shaft is advantageous to many players, especially shorter hitters such as ladies and seniors. Wedges virtually always have steel shafts as the accuracy and consistency is of primary importance.
The higher the number of the iron, the shorter its shaft will be, allowing the player a more controlled and consistent swing. The resulting reduction in clubhead velocity is overcome by an increase in clubhead mass.
Grip
The grip covers the top of the shaft enabling the golfer to hold the club comfortably. Modern grips are generally made from rubber, sometimes inlaid with cord, but some players still prefer a traditional leather wrap. Even though materials advances have resulted in more durable, longer-lasting soft grips, they still require frequent replacement as they wear, dry out or harden.By the rules of golf
Rules of golf
The rules of golf are a standard set of regulations and procedures by which the sport of golf should be played. They are jointly written and administered by the R&A the governing body of golf worldwide except in the United States and Mexico, which are the responsibility of the United States Golf...
, all iron grips must have a circular cross-section. They may taper from thick to thin along their length (and virtually all do), but are not allowed to have any waisting (a thinner section of the grip surrounded by thicker sections above and below it) or bulges (thicker sections of the grip surrounded by thinner sections). Minor variations in surface texture (such as the natural variation of a "wrap"-style grip) are not counted unless significant.
Numbered irons
The 1 iron, or driving iron, is the lowest lofted and longest iron, although WilsonWilson Staff
Wilson Staff is the golf division of Wilson Sporting Goods. The company designs and manufactures a full range of golf equipment, accessories and apparel using the Wilson Staff, Wilson, Profile, and Hope brands....
did make a 0 iron for John Daly
John Daly (golfer)
John Patrick Daly is an American professional golfer on the PGA Tour.Daly is known primarily for his driving distance off the tee , his non-country club appearance and attitude, and his rough-and-tumble personal life. Daly remains one of the most popular and intriguing figures on the PGA Tour...
. Often called a butter knife because of its looks, the 1 iron is commonly regarded as the hardest club in the bag to hit, and is now virtually obsolete. Lee Trevino
Lee Trevino
Lee Buck Trevino is an American professional golfer. He is an icon for Mexican Americans, and is often referred to as "The Merry Mex" and "Supermex". He won six major championships over the course of his career.-Early life:...
is famously quoted, after he had almost been struck by lightning at the 1975 Western Open
Western Open
The Western Open, a professional golf tournament, was first played in 1899. At the time of its 2006 playing, the Western Open was the 3rd oldest active PGA Tour tournament, after the British Open and U.S. Open...
, that if he were out on the course and it began to storm again he would take out his 1 iron and point it to the sky, "because not even God can hit a 1 iron."
The 2 to 9 irons traditionally made up a standard set of irons, although with technological advances, changes to specifications and preferences of the average golfer, the 2 iron is now generally omitted, and a pitching wedge
Pitching wedge
A pitching wedge is a wedge used to hit a shot with higher and shorter trajectory than a 9-iron and a lower and longer trajectory than a gap wedge.-Design/history:...
included. A modern matched set of irons will often also have a sand wedge. The 2 iron's place in the bag is often taken by a third wedge
Wedge (golf)
In the sport of golf, a wedge is a subset of the iron family of golf clubs designed for special use situations. Wedges are designed with modified soles designed to aid in shots through the rough or sand. Wedges have the greatest loft of all of the golf clubs, enabling the ability to produce spin...
. Increasingly, with the introduction of hybrid clubs that are easier to hit than the longer irons, the 3 and 4 irons are also omitted.
Due to the average golfer's desire to hit the ball farther, the loft on modern irons is much less than that on irons from even the late 20th century. For example a modern 9 iron has comparable loft to a 7 iron from the 1990s. Manufacturers have been able to reduce loft without compromising usability, by moving weight into the sole of the clubhead, thereby lowering the center of gravity
Center of gravity
In physics, a center of gravity of a material body is a point that may be used for a summary description of gravitational interactions. In a uniform gravitational field, the center of mass serves as the center of gravity...
and enabling the ball to be launched on a higher trajectory than would otherwise be the case.
Wedges
Wedges are a subclass of irons which are designed for an array of specialist situations. Although similar in design and construction to other irons, they can generally be differentiated by having higher loft than the numbered irons, and a much wider sole, which provides more "bounce", enabling the club to easily cut through long grass, turf and sand without digging in. It is this wide sole that gives the wedge its name, alluding to the profile of its clubhead.Wedges are used mostly for approach shots to the putting green, getting the ball out of tough situations, and to escape from hazards. They are designed to produce a high, short trajectory with a high degree of spin, all of which cuts down on the distance the ball will roll after landing. Most golfers will generally have at least two wedges, traditionally a pitching wedge and a sand wedge, with a lob wedge or a gap wedge commonly being added to provide additional options. Wedges are usually identified by their loft (56°, 62°, etc.) or letter denoting their function (PW, GW, SW, LW, etc.).
- The pitching wedgePitching wedgeA pitching wedge is a wedge used to hit a shot with higher and shorter trajectory than a 9-iron and a lower and longer trajectory than a gap wedge.-Design/history:...
is the most similar in design and function to other short irons, sometimes even designated as a "10-iron", and is usually included in a set of matched irons. - The gap wedgeGap wedgeA gap wedge, also known as an approach wedge, is a wedge used to hit a shot with higher and shorter trajectory than a pitching wedge and lower and longer trajectory than a sand wedge...
was created to fill the gap between the pitching and sand wedges. With modern pitching wedges having much less loft than previous generations, and because sand wedges had generally remained the same, another wedge was needed to fill this gap that had opened up between clubs. The gap wedge has a loft similar to that of an old pitching wedge, around 52°, and can also be found labelled as an "Approach", "Dual", "Utility", or "Attack" wedge. - The sand wedgeSand wedgeAn open faced club, sand wedge, or sand iron, is a wedge primarily designed for use out of sand bunkers. It has the widest sole of any wedge, which provides the greatest amount of bounce, allowing the club head to glide through sand and avoid digging in.-History:Gene Sarazen began to win...
, or sand iron, is primarily designed for use out of sand bunkers. It has the widest sole of the wedges that provides the greatest amount of "bounce", which allows the clubhead to glide through sand and avoid digging in. - The lob wedgeLob wedgeA lob wedge, also known as a lofted wedge or a L-Wedge is a wedge used in the sport of golf, known for being one of the shortest-hitting clubs and providing the most loft on a shot. Lob wedges are used to produce shots with a very high arc, and are most often used for shots over hazards and other...
has a high degree of loft designed to produce shots with a very high arc, and are most often used for shots over hazards and other obstructions. - The ultra lob wedge is a highly specialized, extremely high-lofted lob wedge, that is designed for situations where an almost vertical launch is required. They are generally only made by speciality companies, and are not in common usage.
Given the choices available to the modern golfer, the traditional pair of pitching wedge and sand iron is starting to become less common as players opt for a selection wedges with an array of different lofts and bounce angles. For example, a player may pick two gap wedges, one with low bounce but greater loft than a pitching wedge, and the other with similar bounce but less loft than a sand wedge, then add a lob wedge and forgo both of the traditional wedges.
Specifications
The following table provides a guide to the typical specifications of modern irons.| Iron | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | PW | AW | SW | LW | ULW |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| LoftStandard loft angles vary slightly between models of club. | 11° | 14° | 17° | 20° | 23° | 26° | 29° | 33° | 37° | 41° | 45° | 50° | 55° | 60° | 64° |
| LieDifferent golfers require lie angles that may be as much as +/- 3 degrees than the standard ones listed. | 59° | 59.5° | 60° | 60.5° | 61° | 61.5° | 62° | 62.5° | 63° | 64° | 65° | 65° | 65° | 65° | 65° |
| Length (in)Standard lengths. Golfers may have different shaft lengths to suit their game. | 40.5 | 40 | 39.5 | 39 | 38.5 | 38 | 37.5 | 37 | 36.5 | 36 | 35.5 | 35.5 | 35.25 | 35 | 35 |
The following table provides a guide to the typical specifications of irons through to the mid 1990s.
| Iron | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | PW | SW |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Loft | 14° | 17° | 20° | 24° | 28° | 32° | 36° | 40° | 44° | 48° | 52° | 56° |
| Lie | 54° | 55° | 56° | 57° | 58° | 59° | 60° | 61° | 62° | 63° | 63° | 63° |
| Length (in) | 39.5 | 39 | 38.5 | 38 | 37.5 | 37 | 36.5 | 36 | 35.5 | 35 | 35 | 35 |