16 Gauge vs 17 Gauge Tennis Strings: Thickness Guide

When shopping for tennis strings, choosing the model is only half the battle. Once you select a string (like Luxilon ALU Power or Solinco Hyper-G), you must choose the gauge—the thickness of the string. Choosing between a 16 gauge vs 17 gauge string highlights how cross-sectional area changes baseline playability.

String gauges are numbered counter-intuitively: the higher the gauge number, the thinner the string. A standard 15 gauge string is thick, while an 18 gauge string is ultra-thin. Within the performance market, the choice almost always comes down to 16 Gauge (1.30mm) vs. 17 Gauge (1.25mm).

To compare how string thickness affects baseline spin, control, and durability under identical playtest conditions, I strung a 100-square-inch frame with Luxilon ALU Power 16 and another with Luxilon ALU Power 17, both pulled to 52 lbs. In this guide, I will break down the science of string gauge metrics.

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1. The Gauge to Millimeter Reference Guide

Before analyzing performance, look at how standard tennis string gauges translate to millimeters:

• 15 Gauge (1.35mm): Very thick; maximizes durability for extreme string breakers.
• 16 Gauge (1.30mm): Standard thickness; the default starting point for most adult players.
• 16L Gauge (1.28mm): A hybrid "light" size, bridging the gap between 16 and 17.
• 17 Gauge (1.25mm): Thinner profile; maximizes spin potential, pocketing, and comfort.
• 18 Gauge (1.15mm - 1.20mm): Ultra-thin; maximum feel and elastic power, but breaks quickly.

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2. On-Court Playtest Comparison

Trading groundstrokes from the baseline, the two gauges behave differently:

Spin Potential and Launch Angle

The 17 Gauge (Luxilon ALU Power 17) offers superior topspin. Because the string is thinner, it has a smaller surface area, allowing it to penetrate deeper into the felt of the ball during impact. This "bite" generates more ball rotation.

Additionally, the thinner profile reduces the friction at string crossings, allowing for faster main-string snapback. My topspin forehands cleared the net with a safe margin before diving sharply inside the baseline.

The 16 Gauge (Luxilon ALU Power 16) has a flatter, more linear launch angle. Because the strings are thicker, they slide less, resulting in a firm string bed. It is ideal for players who hit flat groundstrokes and want a predictable, solid response without excessive launch height.

Durability and Shearing

This is where the 16 gauge shines. If you are a chronic string breaker who snaps polyester strings in under 6 hours of play, the 16 gauge is a necessary choice. The extra mass resists the friction rubbing that causes strings to notch and shear. The 17 gauge notches faster, meaning hard topspin hitters can snap them in half the time.

Comfort and Feel

The 17 Gauge is more comfortable. The thinner string is more flexible, deflecting deeper on impact and absorbing more high-frequency vibration. If you manage wrist or elbow strain but want to play with polyester, the 17 gauge is much friendlier on your joints.

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3. Mechanical Physics of String Thickness

To understand why these minor millimeter differences change your shots, we must examine the physics of the string bed:

Stress Per Unit Area

When a tennis ball collides with the string bed, it exerts a massive force: [\text{Stress} = \frac{\text{Force}}{\text{Area}}] Because a 17 gauge string has a smaller cross-sectional area, it experiences higher stress per unit area under identical impact forces. This causes the string to stretch further, yielding more flex (comfort) and elastic energy return (power). Conversely, a 16 gauge string has more carbon mass to distribute the force, resulting in a stiffer response.

Tension Decay and Elastic Limit

• 16 Gauge Tension Stability: The higher material mass of a 16 gauge string means it operates well within its elastic limit. It retains its tension and structural integrity longer, offering a longer playability window.
• 17 Gauge Tension Decay: Because the thinner string is stretched closer to its elastic limit on every hit, it loses tension faster. You will experience a "mushy" or dead string bed response sooner than with a 16 gauge setup.

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4. Pairing Gauges with Your Racket's String Pattern

Choosing the right gauge requires coordinating with your racket's string pattern density:

Open String Patterns (16x19 or 16x18)

In an open string pattern, the strings are spaced far apart, allowing for significant sliding and friction.

• Recommended Gauge: 16 Gauge (1.30mm).
• Why it fits: The open pattern already generates massive spin. Pairing it with a thicker 16 gauge string helps control the launch angle, provides stability, and prevents early string breakage.

Closed String Patterns (18x20 or 16x20)

In a closed string pattern, the strings are packed tightly together, creating a stiff, control-oriented string bed.

• Recommended Gauge: 17 Gauge (1.25mm) or 18 Gauge (1.20mm).
• Why it fits: The tight pattern naturally limits string movement and spin. Using a thinner gauge opens up the sweet spot, increases ball bite, and adds needed comfort to an otherwise stiff setup.

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5. Detailed Stroke Performance Analysis

Let's break down how each gauge performs across specific tennis strokes:

Groundstrokes: Flat Drives vs. Topspin Loops

• 16 Gauge: Exceptional for flat hitters who strike the ball horizontally. The firm string bed provides a consistent, predictable launch angle.
• 17 Gauge: Premier choice for topspin baseline loops. The ball-biting properties produce heavy, high-bouncing topspin that forces opponents back.

Slices: Control vs. Bite

• 16 Gauge: Offers a very consistent bed response, making it easy to hit flat, low-skidding defensive slices.
• 17 Gauge: Bites the ball exceptionally well on slice backhands, allowing you to carve under the ball for extreme backspin.

Net Volleys: Redirection vs. Touch

• 16 Gauge: Extremely stable when blocking back fast passing shots. The frame resists twisting, letting you punch volleys deep.
• 17 Gauge: Delivers superior touch and pocketing feedback, making drop volleys and delicate angles easy to carve out.

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6. Summary Verdict: Which Gauge Fits You?

• Choose a 16 Gauge String (1.30mm) if you are a hard hitter, break strings frequently, hit a flat ball, and prioritize durability and constant tension retention.
• Choose a 17 Gauge String (1.25mm) if you hit with topspin, want a softer, more cushioned impact feel, and want better touch on volleys and drop shots.