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Swing Bench Fit Spokane, WA · Ledger open since 2009
Home · Shaft Reference

What the Numbers on a Shaft Actually Mean

Weight, flex letter and torque are printed on every shaft, and none of the three tell the whole story on their own. Here is how we read them on the bench.

Weight

The Variable That Moves the Most

Grams, measured before anything else on the bench.

Shaft weight is the single number we trust the most, because it is measured directly on a scale rather than inferred from a letter code. Two shafts stamped "regular" from two different makers can differ by fifteen grams or more, which changes total club weight and swingweight far more than the flex letter suggests it should.

As a rough rule, a heavier shaft slows a fast, aggressive transition down into something more repeatable, while a lighter shaft helps a slower, smoother swing generate speed it would not build on its own. Neither direction is universally correct; it depends on tempo, not on handicap.

Flex

A Letter Code, Not a Standard

Regular, stiff and firm mean different things depending on who stamped the shaft.

Flex letters are not regulated across manufacturers, which is why a stiff shaft from one line can measure softer on a deflection board than a regular shaft from another. On the frequency rig we check actual cycles per minute rather than trusting the label, and compare that reading against swing speed and tempo from the launch monitor before recommending anything.

A shaft that feels right off the rack and a shaft that measures right on the rig are not always the same shaft. When they disagree, the rig wins the argument.

Torque

The Number Everyone Skips

Lower torque resists twisting through impact. It is not automatically better.

Torque describes how much a shaft twists around its own axis during the downswing, measured in degrees. A low-torque shaft resists that twist and tends to feel firmer and more direct, which suits a player with a fast, aggressive hand release. A higher-torque shaft flexes more through the twist, which can help a slower, less active release square the face without extra manual effort.

Low torque is not simply the premium option. Fitting a low-torque shaft to a slow, passive release is a common mistake we correct on the bench, usually surfacing as a consistent push or slice the golfer assumed was a swing flaw rather than a component mismatch.

Reference Table

Weight Class at a Glance

Rough starting points only. A fitting session replaces every row here with a number specific to your own swing.

Iron shaft weight classes and general fit
ClassWeight (steel eq.)Typical swingTorque range
Light90–100gSlower tempo, seeking added speed3.5–5.0°
Mid105–115gModerate tempo, most common fitting outcome2.8–3.6°
Heavy120–125gFast, aggressive transition2.2–2.9°
Tour-weight130g+Very fast, seeking maximum control1.8–2.4°

Full current inventory by weight class is on the component wall page.

Read It on the Rig

Skip the Chart, Get Your Own Numbers

A shaft fitting session runs the frequency rig and launch monitor together and writes the result on a ledger card, not a generic recommendation.