StewMac 2-in-1 Precision Straightedge 12-18 in - Professional Tool

In this review of the StewMac 2-in-1 Precision Straightedge 12-18 in the bottom line is simple: this is a workshop-grade tool for luthiers and techs who need repeatable, measurable straightness over the scale length of guitars and larger instruments. The review finds the straightedge'sdual-sided precision and guaranteed tolerances provide the single biggest reason to buy - it removes guesswork from neck and fretwork setups while remaining lightweight and comfortable to handle.

Key Features

• Dual-sided functionality: Two precision-milled sides give you two working edges in one tool so you can switch depending on the clearance or surface you need to check.
• Accurate tolerances: Precisely milled edges maintain tolerances of.0015in per ft to deliver reliable, repeatable straightness checks for professional setups.
• 6063 aluminum construction: Industrial-grade aluminum keeps the straightedge light to hold while providing a stable reference that resists warping in shop conditions.
• Black anodized finish: The finish reduces surface wear and gives a durable working face that stands up to regular contact with frets and fingerboards.
• Ergonomic design: The slim profile and balanced weight make the tool easy to maneuver along necks, bridges, and fingerboards without hand fatigue.
• Versatile length: The 12-18 in range covers most guitar and bass scale lengths, making it useful for a wide range of larger fretted instruments.

Who It's For

The straightedge is aimed at professional luthiers, repair techs, and serious hobbyists who routinely set up guitars, basses and other larger fretted instruments and need a dependable reference tool. It is especially useful when doing fret leveling, neck relief checks, and bridge alignment where small deviations matter.

Those who should look elsewhere include casual players who only need occasional checks and prefer a lower-cost plastic gauge, or specialists who require an ultra-long reference for full-body instruments beyond the 18 in range; for everyday hobby bench use the StewMac offers precision that may be more than needed.

Pros & Cons

Pros

• High accuracy with.0015in per ft tolerances gives confidence for professional setups.
• Dual-sided milling provides flexibility for different tasks without changing tools.
• Lightweight 6063 aluminum construction is comfortable to use and resistant to shop wear.
• Black anodized finish extends the life of the working edges under regular use.

Cons

• Length is limited to 12-18 in, so it may not cover very long instruments or full-body straight references.
• Precision tool requires careful handling to maintain accuracy; it is overkill for casual, infrequent checks.

Specifications

Brand	StewMac
Model	2-in-1 Precision Straightedge, 12-18 in
Material	6063 aluminum
Finish	Black anodized
Accuracy	.0015in per ft
Functionality	Dual-sided precision-milled edges
Intended use	Guitars, basses and larger fretted instruments

Our Verdict

The StewMac 2-in-1 Precision Straightedge 12-18 in is a practical, durable reference for luthiers and repair techs who need accurate, repeatable straightness checks across guitar and bass scale lengths. Itsdual-sided precision, light weight and hard-wearing finish make it good value for professionals; casual users may find the precision greater than required.

Frequently Asked Questions

Is this straightedge accurate enough for professional fretwork?
Yes. The edges are precision milled to.0015in per ft, which is suitable for professional fret leveling and neck relief checks.

Will the finish protect the edges during regular shop use?
The black anodized finish reduces wear on the surface and helps the tool hold up under routine contact with frets and fingerboards.

Is the length suitable for all instruments?
The 12-18 in length covers most guitars and basses, but it may be short for very long instruments or full-body straight references.