StewMac String Action Gauge And Ruler, Inches - Precise Guitar Setup

In this review of the StewMac String Action Gauge, the bottom line is simple: this pocket-sized stainless steel ruler is for players and techs who want fast, repeatable setup measurements without guessing. Built by StewMac with a lifetime promise, the gauge makes it easy to check string height at frets, nut slot depth, saddle adjustments and pickup polepiece height with professional accuracy, so those who care about playability and intonation will appreciate having it on hand.

Key Features

• Built to last: The stainless steel construction and StewMac Lifetime Promise mean the gauge is made for years of shop use without losing accuracy.
• Fast, accurate measurements: Precision-etched markings let the user quickly measure string height, nut slot depth, saddle depth and pickup polepiece height for reliable setup work.
• Progressive string height scale: The slide-across-fret scale provides quicker action readings than a standard ruler, so checking multiple frets is faster.
• Multi-purpose ruler: Beyond guitar setup, the gauge doubles as a more accurate depth guide for router work and other small shop tasks.
• Conversion chart included: A fractional/decimal/metric reference chart on the back makes fast conversions easy during setup adjustments.

Who It's For

The gauge is aimed at guitarists, luthiers and techs who perform regular setups and adjustments and want a compact, precise tool that fits in a pocket or tool roll. Its clear, etched markings and progressive action scale are useful when dialing in action, nut slots and saddle height on both acoustic and electric guitars and basses.

Players who never work on their instrument or who prefer electronic measuring tools may find this manual gauge less useful; also, users who need metric-only markings should note this model is imperial-focused but includes a conversion chart on the reverse for quick reference.

Pros & Cons

Pros

• High-quality stainless steel build backed by a lifetime promise for durable shop use.
• Fast, repeatable readings with a progressive string height scale that speeds setup checks.
• Multi-use functionality for router depth and other small measurements beyond instrument work.
• Helpful conversion chart for quick fractional, decimal and metric reference during adjustments.

Cons

• Some users find the etched lines harder to read in low light, so good lighting helps accuracy.

Specifications

Brand	StewMac
Material	Stainless steel
Scale	Imperial (in) progressive string height scale
Primary uses	String height, nut slot depth, saddle depth, pickup polepiece height
Extras	Fractional/decimal/metric conversion chart on back
Durability promise	Lifetime Promise

Our Verdict

The StewMac String Action Gauge is a compact, dependable tool for anyone who sets up guitars or basses regularly; its stainless steel build, progressive scale and conversion chart make common measurements faster and more reliable, so it represents good value for serious players and techs despite a slightly higher price than a basic ruler.

Frequently Asked Questions

Is this gauge metric?
The gauge is imperial (in) but includes a fractional/decimal/metric conversion chart on the back for quick reference.

Can it measure nut slot depth and saddle depth?
Yes, the etched scale and progressive string height markings are designed to check nut slots, saddle depths and string action accurately.

Will the markings wear off?
The precision-etched markings are durable on stainless steel and intended to remain readable through normal shop use, backed by StewMac's Lifetime Promise.