StewMac 18″ Precision Straightedge (3850) – Stainless Steel Machined Guitar Tool for Fretboard, Neck, & Setup Checks – Pro Luthier Alignment Tool

The StewMac Precision Straightedges are the gold standard for guitar neck and fret evaluation, ensuring accuracy for truss rod adjustments, fret leveling, and neck relief checks. Designed for professional luthiers and repair technicians, these straightedges provide unparalleled precision and durability.Crafted from ultra-high-grade stainless steel, each straightedge features a satin finish for improved visibility and the ability to mark measurements with a pencil. The narrow beveled edge allows for precise gap inspection, making it easy to detect uneven frets and neck imperfections. Guaranteed to ±.0015" per foot accuracy, these tools are trusted for professional guitar setups.Available in four sizes to accommodate different instruments and applications:#3849 - 12" x 1.5" x 0.079" (304mm x 38.1mm x 2mm) – Ideal for mandolins, ukuleles, and short-scale instruments#3850 - 18" x 1.5" x 0.079" (457mm x 38.1mm x 2mm) – Great for guitars and part of the Basic Setup Kit#3799 - 24" x 1.6" x 0.118" (609mm x 40.6mm x 3mm) – Designed for acoustic and electric guitars, compatible with the Neck Set Gauge#3800 - 36" x 1.6" x 0.118" (914mm x 40.6mm x 3mm) – Perfect for bass guitars and long-scale instrumentsEach straightedge undergoes a rigorous 13-step manufacturing process and is individually inspected to ensure maximum precision. Unlike aluminum alternatives, these tools resist bending and denting, ensuring reliable performance for years to come.Perfect for luthiers, DIY musicians, and even precision woodworking, the StewMac Precision Straightedges deliver professional results in every setup.

• PRECISION MACHINED ACCURACY: 18″ stainless flat reference surface engineered for maximum accuracy with neck relief and fret evaluations with tolerances of ±.0015" per foot
• VERSATILE DESIGN: Thick stainless steel with narrow beveled edge helps you quickly assess bow, twist, and fret level deviations during setups, refrets, and neck work
• CLEAR, EASY ALIGNMENT: Smooth, precision-ground edge provides a reliable baseline against which you can measure
• EXPERT WORKSHOP TOOL: Durable steel resists bending while satin finish allows for easy pencil markings. Ideal for guitars, basses, and other stringed instruments
• LIFETIME PROMISE & EXPERT SUPPORT: All StewMac tools are backed by our Lifetime Promise for lifelong durability and our expert tech support is there when you need it most