What Does a .355 Golf Shaft Tip Mean? Understanding Parallel and Taper Tips

When shopping for iron shafts, you may notice two specifications for the same model: .355 and .370.

So, what exactly makes them different, and what do they represent? Is it stiffness? Weight? Or perhaps different launch characteristics?

Actually, it is none of these.

.355 and .370 refer to the outside diameter of the very tip of the shaft—the part that is inserted into the clubhead's hosel—measured in inches. While this may seem like a very minor difference in size, it is critical to whether or not a shaft can be properly installed into your clubhead.

This brings us to a detail you might have never noticed: Taper Tip versus Parallel Tip shafts.

However, before we delve into the differences between them, let’s first understand why iron shafts are divided into these two tip diameters.

Why Are Iron Shafts Divided into .355 and .370?

When assembling golf clubs, it’s not as simple as just inserting the shaft into the clubhead.

The part where the clubhead connects to the shaft is called the hosel. Since different clubheads are designed with different internal hosel diameters, shafts must be manufactured with a corresponding tip diameter.

For iron shafts, the two most common specifications are:

• • .355: Typically a Taper Tip

  • .370: Typically a Parallel Tip

Beyond the size and shape of the tip, there is another intuitive difference: the original shaft length at the time of manufacture.

Generally, .355 Taper Tip shafts are produced with different original lengths for each specific iron number. For instance, the shafts designed for a 4-iron, 5-iron, and 6-iron come in different lengths from the factory.

In contrast, .370 Parallel Tip shafts are typically produced with the same, uniform length for all irons from 2-iron through PW. A club technician then trims the tip based on the specific iron number according to the manufacturer's trimming chart, and finally adjusts the overall length of the club from the butt end.

In short:

.355 Taper Tip: Different iron numbers → Original shaft lengths are typically different.
.370 Parallel Tip: Different iron numbers → Original shaft lengths are typically the same, distinguished by tip trimming.

Because of this, the difference between .355 and .370 is not just "one is thinner and one is thicker"; it actually represents two different design and assembly logics.

Next, let’s discuss exactly what Taper Tip and Parallel Tip shafts are.

Parallel Tips and Taper Tips

Parallel Tip — Common Specification: .370

A "Parallel Tip" refers to a shaft where a section at the tip maintains a consistent outside diameter. When viewed from the side, this section features a parallel profile.

On irons, the common Parallel Tip specification is a .370 diameter.

A key characteristic of Parallel Tip shafts is that they are generally manufactured at a uniform length and then utilized for different iron numbers through varying trimming methods.

For example, if the same .370 Parallel Tip shaft is being installed into a 4-iron, 7-iron, or PW, a technician will perform a specific amount of "tip trimming" from the tip end based on the manufacturer's trimming instructions, then adjust the shaft from the butt end to reach the desired final club length.

KBS .370 Parallel shafts utilize this method. A word of caution: The trimming method affects the shaft's final performance, so it must be done according to the specified trimming guidelines.

What Is the Difference Between Tip Trimming and Butt Trimming?

Shaft trimming can generally be divided into two main categories:

Tip Trimming
This involves cutting the shaft from the end closest to the clubhead. Because this area is directly related to the bending profile of the shaft, changing the amount of tip trimming can alter the feel of the shaft's stiffness and its reaction.

Generally, increasing tip trimming makes the tip section stiffer; therefore, it cannot be viewed simply as "shortening the shaft."

Butt Trimming
This involves cutting the shaft from the grip end, primarily used to adjust the overall club to the desired finished length.

Therefore, when assembling a Parallel Tip shaft, you cannot simply cut it based on your desired final length; you must first verify the shaft model, iron number, and the manufacturer's trimming chart.

Different shaft series have their own designs and trimming specifications, and values from one model cannot be applied to another. Once too much tip has been trimmed, it cannot be recovered; therefore, we recommend leaving the actual operation to a professional technician.

Taper Tip — Common Specification: .355

Taper Tip shafts are entirely different.

The tip of the shaft does not maintain a constant diameter. Instead, it gradually thickens starting from the .355 measurement at the very tip, creating a subtle tapered structure.

Because of this, .355 Taper Tip shafts must be installed into a corresponding Taper Hosel to ensure a proper fit.

Another key difference from Parallel Tips is that Taper Tips are usually manufactured to specific lengths based on the iron number.

For instance, when purchasing a set of .355 Taper Tip iron shafts, the shafts for the 3-iron, 4-iron, 5-iron, and all the way to the PW come in different raw lengths, rather than taking a single identical shaft and distributing it across different iron numbers via tip trimming.

Taking the KBS .355 Taper Shaft as an example, adjustments are usually made by trimming only from the butt end to the desired final club length, without the need for tip trimming by iron number as is required for .370 Parallel shafts.

In short, you can think of the two as follows:

.370 Parallel Tip: Different iron numbers are configured via tip trimming, followed by butt adjustment for final length.

.355 Taper Tip: Shaft specifications for different iron numbers are already pre-divided; final length is primarily adjusted from the butt end.

Is There a Difference in Performance Between .355 and .370?

At this point, a common question arises:

Since the structure and assembly methods are different, does playing .355 versus .370 result in different performance?

It is important to clarify a common misunderstanding here.

Solely based on the tip diameter of .355 and .370, one cannot directly determine which is stiffer, softer, or which produces a higher or lower launch.

The primary difference is the diameter at the hosel, meant to accommodate different hosel sizes; the performance difference does not arise from the .355 or .370 specifications themselves.

What truly influences a shaft's performance includes:

• Weight

• Flex

E.I. curve

• Length

• Structural design

• Trimming and assembly methods

Because .370 Parallel Tips require tip trimming, technicians must pay special attention to the manufacturer's trimming guidelines. If the prescribed trimming method is altered, the shaft's final performance will naturally change.

Therefore, when choosing between .355 and .370, your first consideration should not be your desired launch, but rather which specification your clubheads actually use.

Why Are Iron Shafts Most Commonly Found in .355 and .370?

Strictly speaking, iron shafts are not the only ones with variations in tip size.

Every club shaft must correspond to the hosel design of its clubhead, so drivers, fairway woods, hybrids, and irons each have their own common tip diameters.

For example, the tip specs for wood shafts are different from those of irons, and hybrids may use different diameters depending on the product and design.

However, for iron shafts, the .355 Taper Tip and .370 Parallel Tip specifications have coexisted for a long time. Since many shaft products are offered in different versions, it is easy for golfers to encounter these two numbers when buying or replacing shafts.

In other words, .355 and .370 are not parameters used to compare shaft performance, but rather an assembly specification between the clubhead and the shaft.

How Do I Know If My Clubhead Is .355 or .370?

Some club brands publish hosel or tip diameter information in their product technical specifications, so you can first verify this using official manufacturer data.

However, if you have clubs that you have used for a while, especially if you have had them re-shafted or modified, you cannot definitively confirm their current status based solely on brand, model, or visual inspection.

Given that the difference between .355 and .370 is extremely small, it is not suitable for judgment by the naked eye.

Therefore, before replacing your shafts, the safest method is to let a professional technician verify the actual size of your clubhead hosel and existing shafts before choosing the correct specification for assembly.

.355 and .370 are not performance differences, but vital details for club assembly.

The next time you see .355 or .370 on a KBS shaft specification, don't mistake them for another type of flex or performance parameter. Their primary function is to ensure that shafts of different designs correctly fit their corresponding clubheads.

The different structures of Parallel Tip and Taper Tip have also led to the development of different trimming and assembly methods.

For the average golfer, there is no need to memorize every trimming value. The most important thing is to confirm the specification used by your clubheads before purchasing or replacing shafts, and then leave the assembly to a professional technician following the manufacturer’s guidelines.

After all, even a tiny difference in size can be the key to whether or not a shaft can be properly assembled into a complete club.

Conclusion

When replacing iron shafts, do not rush to order based solely on weight and stiffness. It is far more important to first confirm the tip specification of your clubheads.

Since the difference between .355 and .370 is not easily detectable to the naked eye, if you are unsure, it is recommended to have a professional technician measure them and handle the trimming and assembly according to manufacturer standards.

If you are considering a KBS shaft upgrade, you can bring your existing clubs to our store, where technicians can help confirm your clubhead specs and assembly methods. If you also wish to re-evaluate your current setup, we can further identify the perfect match for you through fitting.

Seemingly only a 0.015-inch difference, it hides quite a few nuances in club design and assembly. Next time you see .355 or .370, you’ll know it’s not just a number on a spec sheet, but critical information that determines whether a shaft can be correctly installed.

Further Reading

Beyond Parallel and Taper tips, did you know that the "steps" on your shaft also secretly affect your shot performance?

— "Why Do Iron Shafts Have Steps? The Secret Behind Feel Is Right Here!"

Have you heard of "torque"? Understand the little secret that only insiders know in 3 minutes!

— "What Is Golf Shaft Torque? How Is It Different from Flex? Understanding the Difference Between Torque and Flex"