This section of the 2nd Swing Fitting site explains and defines golf club specifications, such as loft and lie, bounce angle, and more.

Tapered Shaft Tip

Golf Club Specs: Tapered Shaft Tip

Golf Club Specs: Tapered Shaft Tip

This is a configuration where the outside diameter of a shaft through the insertion area decreases. Unfortunately, tapered shafts cannot be shortened as easily as parallel shafts since they and require adjustable attachments to connect shaft, hosel and clubhead after a cut. Otherwise, the resulting bottom outside diameter would not fit all the way down into the hosel.

A graphic artist’s rendering of a tapered shaft end.

A graphic artist’s rendering of a tapered shaft end.

Parallel Shaft Tip

Golf Club Specs: Parallel Shaft Tip

Golf Club Specs: Parallel Shaft Tip

The configuration of the bottom-end of a shaft is where the outside diameter does not change throughout the insertion area. A benefit of parallel tip shafts in irons is that manufacturing can use blanks to both tip and butt cut to achieve the desired length and flex for each club in a set (This does not produce a set of constant weight shafts.).

Here's a clear-cut diagram example of a taper versus parallel golf club shaft tip.

Here’s a clear-cut diagram example of a taper versus parallel golf club shaft tip.

Shaft Tipping

Golf Club Specs: Shaft Tipping

Golf Club Specs: Shaft Tipping

This is the removal of any particular length from the tip-end of a shaft. Tipping has the effect of making the shaft play stiffer — generally a third to a half flex for every 1/2 inch removed. Tipping can only be accomplished with parallel or unitized or tapered shafts.

These are the shaft tips, near the hosel -- where the ferrule and shaft connect -- and clubhead, where sections of shafts are removed or greater stiffness.

These are the shaft tips, near the hosel — where the ferrule and shaft connect — and clubhead, where sections of shafts are removed or greater stiffness.

Modern materials (graphite, composites, metals)

Golf Club Specs: Modern materials (graphite, composites, metals)

Golf Club Specs: Modern materials (graphite, composites, metals)

Shafts, like clubheads, have increasingly benefited golfers with technological advances. Shafts, once made of wood, are now made primarily in graphite and steel. Stainless steel, in all its various gauges, ridges and ripples, remains the most common kind of shaft for irons and putters, although that’s starting to change.

Graphite-shafted clubs are generally lighter and have better vibration absorption characteristics than steel-shafted clubs. They are made up of layers upon thin layers of fiber material held together by various resins, all of which can be adjusted to conform to a certain degree of stiffness or flexibility for each player.

Steel-shafted clubs generally produce more consistent shot patterns and are generally heavier than graphite shafted clubs. Players desiring a softer feel than traditional steel shafted clubs will enjoy steel-shafted clubs equipped with vibration-filtering inserts.

Layered, fiber and resin composite graphite-shafted clubs are generally lighter and have better vibration absorption.

Layered, fiber and resin composite graphite-shafted clubs are generally lighter and have better vibration absorption.

Kickpoint (a.k.a. bend point, flex point)

Golf Club Specs: Kickpoint (a.k.a. bend point, flex point)

Kickpoint (a.k.a. bend point, flex point)

In general, it is believed that the higher the kickpoint, the lower the ball flight and vice-versus. It’s where the shaft bends the most during impact with the ball.

Golf Club Specs: Kickpoint (a.k.a. bend point and flex point)

The point on the shaft where the greatest amount of bending occurs during a downswing right before impact the ball is called the kickpoint or bend point.

A shaft that bends near the head has a low kickpoint. A shaft that bends near the grip has a high kickpoint.

There is an inverse relationship between kickpoint and ball flight. A shaft with a high kickpoint will produce a low ball flight, and a shaft with a low kickpoint will produce a high ball flight.

However, today there is some debate about how significant kickpoint is in determining ball flight. As clubs and golf science become more and more advanced, other relatively new factors are being taken into consideration — such as droop and shaft differential.

 

swingweight matters

Golf Club Specs: Why Swingweight Matters

swingweight chart

A common swingweight chart. It’s important, but let the experts handle it, really.

Why Swingweight Matters

How swingweight works and putting proper golf club weighting to use.

So I was visiting the Twin Cities friendly neighborhood 2nd Swing store in Minnetonka, Minn., this past Monday. I had reached my breaking point with the current set of irons I was using. I had gotten them late last summer and for some reason was not getting consistent shots.

While I will be the first to admit that it was more likely a fault of my slowly declining golf skills, there was something just not right. I met with store General Manager Scott Johnson, who is my two-ball partner and has a vested interest in seeing me play well. (He also enjoys taking my money from our friendly rounds with a wager or two thrown in.)

We put my irons on the swingweight scale.

The first thing I noticed was that the swingweights were all over the place. Maybe two irons were the same. Not only that, but every iron was overall light in weight. What happened?

Remember the good old days when you got a set of irons and it felt like they literally were made of iron? Heavy, great for making divots, and defending your house from intruders (I’ve even heard they can do damage to vehicles when swung with the right force or anger level.).

But the club was heavy and it felt heavy. These days quite a few of the manufacturers have gone to creating irons and iron sets that are lighter, and they promote that fact by stating how a golfer can generate greater clubhead speed for more distance.

We tested that theory by taking brand-new iron sets off the rack and checking the swingweight. All of the sets were lighter than what I recalled as being as “normal” or “standard.”

Sure, you can probably generate more clubhead speed, and the club seems lighter as you swing it. However, you lose the “feel” of the club. As a golfer, one of the most important parts of the game is feel. If you can’t feel where the clubhead is at the top of your backswing, then it’s a crap shoot how the clubhead will get back to the ball at impact. This simple fact is another reminder why it is so important to work with a 2nd Swing clubfitter.

Get either get your existing clubs or that new set of irons properly weighed, have the loft and lie checked and make sure the proper grip size is installed — for starters.

So how did I resolve my problem? The simple, easy, and least expensive way. I purchased some lead tape and started putting strips on the back the clubhead.

After the first strip, I would take some practice swings to see if I could better feel the clubhead. It actually took two strips for lead tape for each iron for me to most consistently feel the clubhead at the top of my swing. The added benefit was I now able to more consistently release the head into the ball, gain a higher ball flight and let the club do the work.

As a golfer, you do not need to understand the terms of swingweight and what the numbering system means. What you need to know is: “Can I feel the club head at the top of my swing?”

If the answer is no, then it may be one of the reasons your iron set is not performing to your expectations. Me, I’m ready get some of my money back from Scott, and we’re both hoping for a long run in our club match play tourney.

Iron Offset and Face Progression

Golf Club Specs: Iron Offset and Face Progression

Iron Offset and Face Progression

Here’s a very simple and helpful illustration of shaft axis through the clubface, albeit for putters.

Golf Club Specs: Iron Offset and Face Progression

What they are and why the difference matters for your golf irons.

Many of you may have heard the term “offset” when discussing iron design.There is another  part of iron design that goes along with offset and truly measures the actual relationship between the shaft centerline axis (its absolute middle) and the clubface (the actual front line border of the face). It is called “face progression” also known as “leading edge progression” or LEP.

Face progression is the measurement from the shaft centerline axis (C/L) of the hosel (and the shaft) in relation to the front leading edge of the clubface.

Different iron designs may have different size hosels. Some may be thinner (say 0.45 inches in diameter), while others may be beefier (say up to 0.60 inches).

Here's an excellent demonstration of iron offset from the hosel to the leading edge of the clubface.

Here’s an excellent demonstration of iron offset from the hosel to the leading edge of the clubface.

Some may have a tapered shape, while others may be more barrel shaped. All these variables will cause very different readings and visual looks in the offset of the clubs. Let’s say an iron has a hosel diameter of a half inch.

If it is designed with a large amount of offset, then the face progression (LEP) may be very small with most of the shaft centerline axis C/L intersecting the clubface very close to the front of the leading edge. 

The centerline axis (C/L) shown here and how it relates to face progression.

The centerline axis (C/L) shown here and how it relates to face progression.

Different iron designs may have different size hosels. Some may be thinner (say 0.45 inches in diameter), while others may be beefier (perhaps up to 0.6 inches). Some may have a tapered shape, while others may be more barrel shaped. All these variables will cause very different readings and visual looks in the offset of the clubs.

Let’s say an iron has a hosel diameter of a half inch. If it is designed with a large amount of offset, then the face progression (LEP), or leading edge progression, may be very small with most of the shaft centerline axis or C/L (These are new terms to most of us worth repeating.) intersecting the clubface very close to the front of the leading edge.

If a club is designed with a smaller amount of offset (and it still has the half-inch hosel diameter), then the LEP will be greater (See diagram above.).

And a larger portion of the front leading edge of the clubface will hang out ahead of the shaft centerline axis or C/L (See diagram below.).

So, what does all this engineering and physics mean to the average golfer?

  • A club designed with greater offset will help position the player’s hands ahead of the ball at address and aid the golfer in hitting down on the ball at impact.
  • It also helps the golfer in squaring up the face and limiting those nasty slices.
  • You can close the face, too, a wee bit to help draw the ball.
  • A better golfer who already is skilled enough to hit a controlled draw may prefer a club with less offset — and more LEP — to help him work the controlled fade shot and lessen the chance of hitting a hook.

Generally, a set of irons will be designed with progressive offset. This means that the longer irons will have more offset than the shorter clubs.

Say a 3-iron has 0.30 inch offset. The 4-iron may have 0.275 inch, the 5-iron 0.250 inch, going down to the pitching wedge with perhaps only 0.10 inch offset. This is because a golfer generally prefers (and requires) less offset as the club gets shorter and has more loft.

The result is that a player will not require as much help hitting a straight shot with a pitching wedge versus a 3-iron. Also, as the loft increases, the backspin will keep the sidespin from over slicing the ball.

So, the next time you are testing out a set of irons, line them all up together to see if they have the progressive offset and face progression that you think will help your game the most. Be sure that you are happy with the set-up and the look of each iron in the set as it transitions from long iron to short.

Good looking short irons (your scoring clubs) are very important so that you can  attack the pin with confidence after that great drive up the middle.

shaft torque

Golf Club Specs: Torque

golf club torque

Golf Club Specs: Torque

Here’s one for the folks who fiddle with their clubs in the garage, the home-schooled golf engineers. One of the facts about golf shafts that you should understand is that of “torque.” This, however, is a slight misnomer since what the shaft manufacturers are really telling you is the shaft’s  torque reading.

That’s because torque is the force that is applied to the shaft causing the shaft to twist along its longitudinal axis. But for the sake of simplicity, I’ll refer to the torque reading as torque. Torque, basically, is the measurement of force used to twist or to stop something from twisting, like a golf clubhead or shaft. 

You know, like trying to wrench free a rusted bolt. 

Let me give you an example of golf shaft torque: Hold your driver firmly by the grip (butt-end) and then grab the club head (tip-end) and twist the club face open, but do not let the grip end move. You’ll see a slight rotational movement of the face. This is a result of the applied torque that you are putting on the shaft.

A rather simple example that will clearly show the effect of torque on a tubular object (which a golf shaft is) would be to use a straw. Next time you buy a milkshake get an extra straw. Hold the straw horizontally with your fingertips on both ends. Now gently rotate your fingertips in opposite directions. You have applied torque to the straw. You’ll see the length of the straw’s body twist.

In years past, the torque of a golf shaft was measured by clamping the butt-end securely in a fixture so it would not move. The tip-end would have a perpendicular 1-foot-long lever attached to it and a 1-pound weight would be hung at the end of the lever. The weight would create a force to twist the shaft “1-foot pound.”

The amount of twist seen in the shaft would be measured in degrees. Now days there are computer controlled machines that calculate the torque very quickly. A golf shaft (say for a driver) with lower torque will have a reading of 3 degrees, whereas one with more torque would be 5 degrees. 

golf club shaft torque machine

The higher the number, the more twist or torque a shaft has. When you swing a driver at full speed, you are exerting many forces on the shaft. Longitudinal bend (flex) and torque are just two of them.

The shaft’s body is not only bending from the force, it also is twisting. The shaft’s tip section would rotate or torque even more if a golf ball was not hit on the exact center of gravity (sweet spot) on the clubface.shaft torque

So, why do we care about a shaft’s torque? For many years when golfers used steel shafts in their drivers, the torque readings were around 2.5 degrees. This was the accepted amount of twist for a shaft and was preferred by the better players. When graphite composite shafts first came on the market their torque was generally higher than steel shafts and better players did not consider them as accurate since the shots tended to spray off-line due to the higher degree of rotation.

As design and manufacturing methods improved, graphite shafts were soon able to hit all sorts of different torque readings including very low readings of below 2 degrees. As it turned out, only a very strong swinger of the club could handle the stiff, harsh feel of these very low-torque shafts.

Even PGA Tour players preferred the 2.5- to 3-degree range. Slower swingers actually preferred a little higher torque, since that design usually produced a higher launch angle and better feel at a slower speed.

Remember, a 240-yard drive that is a few degrees off-line will not be as big a problem as one hit a few degrees off-line at 300 yards.

Swingweight

Golf Club Specs: Swingweight

Swingweight

Golf Club Specs: Swingweight

Club length and its relation to swingweight and then distance or power striking.

Many times a golfer will hear that the longer a club’s shaft is the farther he will hit the ball.

This makes sense when you consider that the club acts like a lever, and we all know that you can more easily move weight with a longer-length lever. However, the problem occurs when the golfer keeps trying longer and longer shafts for better and better and results.

At some point, he notices he could not hit a fairway if his life depended on it.

Eventually, he’ll figure out that he must back down to a length that allows some distance gain, but still keeps the ball in play. The other fact to consider is that if the golfer continues to use the same clubhead as he experiments with ever longer shafts, the swing weight is going up until it weighs out heavier than his sand wedge (which, obviously, is very heavy).

Why is this?

The club’s feel and swingweight (Let’s use a driver as an example.) was fine at standard length, but now at two inches longer, the thing weighs a ton. To understand what happened, we must first understand what “swingweight” actually is.

Many years ago, golfers put together their “matched” set of clubs by not much more than the heft and feel of each one in their hands as they waggled the stick. This might have worked for the extremely skilled player blessed with wonderful feel, but for most folks it produced anything but a matched set of clubs.

It later was determined that even the great Bobby Jones — who had put together set by feel and won multiple tournaments — had clubs that measured a wide range of swingweights when put on a modern-day swingweight scale. 

Eventually, golf enthusiasts decided something must be better than just hefting a club in a hand. So in the 1930s, Spalding Sports, with Mr. Jones’ help, created a “waggle-o-meter.” This quantified the feel and heft of clubs.

A club builder named Kenneth Smith created the basis for the modern-day swingweight scale that uses a type of fulcrum that balances on a pivot point. Smith put the grip end and a portion of the club shaft on one side of the fulcrum. The grip end is stopped at a predetermined length, usually around 14 inches.

The remaining length of the club, along with the clubhead, hangs off the other end of the fulcrum. And a sliding weight on a scale measures how much the remaining end weighs. Then a series of readings called swingweight points will identify how heavy or light a club will feel in the golfer’s hands.

Swingweight scales are widely available online to be used in combination with charts (See the one above.) or especially through golf club fitters, such as 2nd Swing Golf’s experts.

A light-feeling club will measure C7 or C8, and a standard-feeling club will read D1 or D2. Finally, a heavy-feeling club would be E1 or E2. 

When you only increase the length of a club (such as that driver again), but keep the same clubhead and weight, you will see that a longer portion of the club’s length will hang out over the fulcrum, which we already discussed. The longer the length over the fulcrum, the heavier the swingweight reading will be. That indicates a heavier feel.

Unless you begin to remove some actual weight from the clubhead, the reading will continue to climb as you increase the length. You can appreciate this when you heft the longer club and see that it is becoming unwieldy. Conversely, if you cut a club’s length shorter, you must add some weight to the clubhead to keep the swingweight or heft equal to what you had prior to the cut.

So, before you go adding or subtracting length to your clubs, consider the swingweight changes and how this will effect the feel of your club.

Toe-View-SW-showing-sole-bounce1

Golf Club Specs: Bounce

bounce

The lower the bounce angles the higher the likelihood a club will dig into the earth, such as a pitching wedge versus a 5-iron (high bounce). It’s an inverted concept.

Golf Club Specs: Bounce

What is Bounce?

The meaning of bounce in golf.

Bounce: The angle that is formed between the leading edge of the golf club and the trailing edge of the sole.

Clubs with high bounce angles tend not to dig into the turf, while clubs with low bounce angles do have a tendency to dig. While bounce angles for irons (1-9) are designed for optimal performance for the average golfer, different bounce angles in wedges are especially beneficial depending on the conditions of the course being played.

Let’s say that you like to use your sand wedge for most shots in the fairway, rough and around the greens. You may want your wedge to have a little less bounce so that you can play a variety of shots from these different areas.