III. Irons

1. What is an iron?

Irons were originally made using iron, but are now generally made from steel, titanium or a high tech alloy. Irons are smaller than woods and are considered finesse clubs, meant to be used when accuracy is more important than distance.


2. What does the number on the club mean?

For the most part, the number represents the loft of a club. The lower the number, the longer the shaft and the lower the loft of the club, relative to the other clubs in the set. The lower loft and longer length will result in greater distance, but with a concurrent loss of accuracy. This also equates to lower numbered clubs being more difficult to hit properly.


3. What makes a set of clubs?

A set of golf clubs is restricted to no more than 14 clubs, according to the Rules of Golf. What constitutes this set depends on your preferences. In general, a basic, full set of clubs might include the following clubs:
Irons:
3, 4, 5, 6, 7, 8, 9, PW, SW

Woods:
1, 3, 5, 7

and a putter.

This is just a guideline, the clubs you carry should be determined by the type of course you are playing, the weather conditions and your own playing ability. Also keep in mind that there is no minimum requirement. Many players, especially beginners, carry only 7 to 10 clubs.


4. Investment Casting

Investment casting is a highly accurate and precise method of casting or pouring liquid metal. It is a significant improvement over older casting methods. A master die, usually of aluminum, is milled. Wax is then injected into the die and once it has solidified, the die is removed. The positive wax pattern is then dipped into a ceramic 'slurry', which hardens around the wax to create a negative mold. The wax is then melted away and the empty ceramic negative is filled with molten metal, typically stainless steel or titanium. After the metal has cooled, the ceramic negative is broken away, exposing the newly cast clubhead. The new clubhead is finished and polished and then is ready to be assembled into a golf club. For more information on the investment casting process, please visit these websites:

 http://www.rugergolf.com/process.htm http://www.3dsystems.com/ products/ solidobject/thermojet/TJ_Printer_US_InvCast_4_011.pdf


5. Forged

Forging is a process of pressing or hammering the metal into the desired shape. Forging is very similar to what the village blacksmith used to do except today a large machine called a "press" is used instead of a hammer. Dies are "sunk" or cut, by milling the desired impression into hardened steel. The die is then installed into the press and is used to actually squeeze the "blank" into the desired shape. The manufacturer is then presented with a raw forging, which is a close approximation of the clubhead desired. The clubhead must then be finished by milling, grinding and drilling. Forged clubheads are commonly made from soft carbon steel and may rust if not plated. Some forged wedges are deliberately not plated so as to encourage rusting. The rust reduces reflected glare, but does not affect spin.


6. Blade

A blade is an iron head that has no cavity and typically is forged from soft carbon steel, but there have been some models investment cast in 304 stainless steel. Blades are the iron of choice for many pros and top amateurs because they allow better players to more effectively work the ball. This means that better players typically report that it is easier to draw, fade or otherwise deliberately cause direction changing spin when using blade-type irons. The drawback is that blades have a smaller "sweetspot " and so are less forgiving when mis-hit.


7. Cavity Back/Perimeter Weighted

A cavity back iron, also known as perimeter weighted, has generally been associated with investment casting. The design of the clubhead distributes the weight around the perimeter of the head, supposedly producing a large ' sweetspot '. This makes the off-center shots more forgiving, flying longer and straighter, than an off-center shot with a blade-type iron. The drawback is that it is considered more difficult to reliably work the ball with cavity back irons.


8. Notes

When investment cast heads were first introduced, several companies claimed that the feel of the head was lost. These same companies also claimed it was more difficult to work the ball with the cast heads. Keep in mind that most golfers tend to believe that a blade-type iron (usually forged) produces more feel than the cavity back models (usually investment cast). They also say that it is easier to shape the shot using the blades over the perimeter weighted clubs. Before making a decision, you should try a few blades and cavity back irons and see for yourself.

Also be aware that in the past few years "forged cavity back" club heads have hit the market.  The theory is to provide the feel of a forged club with the forgiveness of cast cavity backs. These are fairly new, but the reports from golfers who have these type of clubs have generally been favorable. However, forged cavity back irons typically cost the same as forged blade irons.

Another recent trend in irons is the use of exotic and multiple metals. The most common of these metals are tungsten and copper, for their high density. These materials are typically used to lower the center of gravity (COG) of the clubhead, promoting a higher ball flight. This is particularly helpful to higher handicap players who have trouble getting the ball airborne.


9. Quick Comparison

Investment cast cavity back
  • Peripheral weighting
  • More forgiving
  • Stainless steel
  • Harder to work


Forged blade

  • Central weighting
  • Better feel
  • Carbon steel & chrome
  • Easier to work
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