StewMac Shop Rule 4905-M Precision Metric Ruler

1. Introduction

The StewMac Shop Rule 4905-M is a 15-centimeter (6-inch) precision steel rule designed for accurate measurements in instrument work. This durable tool features clear metric increments, a unique center-finder, and vertical end scales to assist with various precise tasks.

Figure 1: Front view of the StewMac Shop Rule 4905-M.

2. Product Features

• Material: Satin chrome steel for durability and clear readability.
• Measurements: Metric increments in 0.5mm, 1mm, and 1cm.
• Centering Rule: Features a zero point at the center, extending left and right to facilitate locating the center of components like a neck or bridge saddle.
• Vertical End Scales: Small vertical rulers with millimeter increments on each end, useful for measuring heights such as saddles, nuts, and pickups.
• Dimensions: 152mm x 19mm (6" x 3/4").

Figure 2: Back view of the ruler, highlighting the centering rule.

Figure 3: Close-up of the vertical end scale for precise height measurements.

3. Operating Instructions

3.1. General Measurement

Align the edge of the rule directly with the starting point of your measurement. The rule features sharp black etchings for clear readings. For marking, the satin chrome steel surface accepts pencil marks effectively.

3.2. Using the Centering Rule

The center-finder feature has a zero mark at its midpoint. To locate the center of an object, align the zero mark with the desired center point. The scales extending left and right from zero will indicate equal distances from the center, aiding in symmetrical placement or marking.

3.3. Using the Vertical End Scales

For measuring heights, such as string action at the 14th fret, nut height, or pickup height, use the small vertical scales located at each end of the rule. Place the end of the rule flush against the surface from which you are measuring, and read the height directly from the vertical scale.

Figure 4: Measuring guitar string action with the StewMac Shop Rule.

3.4. Tips for Accurate Measurement

• Ensure adequate lighting to clearly read the etched markings.
• Position your eye directly above the measurement point to avoid parallax errors.
• For guitar setup, ensure the instrument is in a stable position, ideally on a workbench with appropriate support.

3.5. Related Instructional Videos

4. Maintenance

To ensure the longevity and accuracy of your StewMac Shop Rule, wipe it clean with a soft, dry cloth after each use. Avoid exposure to harsh chemicals or abrasive materials that could damage the satin chrome finish or etched markings. Store in a dry place to prevent corrosion.

5. Safety Information

WARNING: This product contains chemicals known to the State of California to cause cancer and birth defects or other reproductive harm.

Always handle the rule with care to avoid accidental cuts from its sharp edges. Keep out of reach of children.

6. Specifications

7. Warranty and Support

StewMac products are built to last. If any of our products ever break, wear out, or fail to exceed your expectations, simply return it for a replacement. For further assistance or inquiries, please contact StewMac customer support.

Visit the StewMac Store for more information and products.