StewMac Shop Rule

StewMac Shop Rule, 6" Rule
6" Rule Item # 4905 In stock, ready to ship!
StewMac Shop Rule, 15cm Rule
15cm Rule Item # 4905-M In stock, ready to ship!
StewMac Shop Rule, 12" Rule
12" Rule Item # 6244 In stock, ready to ship!
StewMac Shop Rule, 30cm Rule
30cm Rule Item # 6244-M In stock, ready to ship!
StewMac Shop Rule, 18" Rule
18" Rule Item # 6245 In stock, ready to ship!
StewMac Shop Rule, 45cm Rule
45cm Rule Item # 6245-M In stock, ready to ship!
StewMac Shop Rule, 24" Rule
24" Rule Item # 6246 In stock, ready to ship!
StewMac Shop Rule, 60cm Rule
60cm Rule Item # 6246-M In stock, ready to ship!
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StewMac Shop Rule

The most-used rule in every shop—now in every size you need! With accurate markings, center-finder, and vertical end scales, these easy-to-read precision steel tools will never leave your bench.

For years customers have loved our 6" Shop Rule. From simple setups to complex fine adjustments, we're constantly finding new ways to use this handy rule. From your many requests we now offer the same accuracy in 12", 18", and 24" sizes—and metric versions too.

Accuracy you can count on
Each rule is satin chrome steel with sharp black etchings that is easy to see even in poor light. It easily accepts pencil marks, too. The inch marks are in 16ths, 32nds and 64ths—for fast readings and extreme precision. The metric marks are in centimeters, millimeters, and 0.5 millimeters.

Centering rule
Each rule also includes a centering rule on the reverse. With zero at the center, this rule extends left and right to locate the center of a neck, bridge saddle, or body quickly and accurately.

Vertical end rules
For even more utility, each end is also a vertical rule. The precise scale (1/32" or 1mm increments) is ideal for measuring the height of saddles, nut, and pickups.

The right size for any job
The multiple sizes make these perfect for the everyday jobs in your shop. From setting up action, setting pickup height, measuring scale length, laying out plans, there is a size that is just right for your job.

Here's just a few ways we use them in our shops:
6" rule or 15cm rule: precise small jobs like setting action, nut and bridge height, and adjusting pole pieces.

12" rule or 30cm rule: measuring braces, bodies, laying out plans, and measuring necks on ukuleles and mandolins.

18" rule or 45cm rule: laying out an entire guitar fretboard. From marking centerlines, fret locations and inlays, this is the right rule for the job.

24" rule or 60cm rule: ideal for all building tasks, from measuring scale length, finding the neck angle, determining bridge locations, and laying out neck blanks.


  • Rigid chrome plated steel
  • Satin finish for easy reading and marking
  • Extreme precision: markings in 16ths, 32nds and 64ths or cm, mm, and 0.5 mm.
  • Multiple scales on each rule: vertical, horizontal, and centering


  • The 6" or 15cm rule is 0.75" x 0.040" thick (19mm x 1mm)
  • All other rules are 1.125" tall x 0.040" thick (28.6mm x 1mm)
  • Available in four standard and metric lengths: 6", 12", 18", 24" and 15cm, 30cm, 45cm, 60cm

Want even more versatility? Our Flexible Shop Rules have the same precise measurement features, but can bend and contour to your work. They make it easy to measure in and outside guitars and for laying out pickups on archtops, planning linings and purflings, and so much more.

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