Rule Straightedges | McMaster-Carr

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768 Products

Horizontal Rulers

Corrosion-Resistant Stainless Steel Rulers

Made to last, our most corrosion-resistant rulers are stainless steel and have wear-resistant etched markings.

Certified Corrosion-Resistant Stainless Steel Rulers

A calibration certificate traceable to NIST is included with these stainless steel rulers.

Certified Lightweight Aluminum Rulers

Ensure accurate measurements with these certified rulers.

Lightweight Aluminum Rulers

Made of aluminum, these rulers are an economical alternative to stainless steel rulers.

Easy-to-Read High-Contrast Rulers

Numbers and graduations etched in light colors are easy to see on a black background.

Easy-to-Read Rulers with Bold Markings

Rulers have large numbers and deeply etched graduations.

Transparent Rulers

Keep your workpiece in view as you measure with these see-through rulers.

Wood Yardsticks

Made of wood with a clear protective coating, this ruler is an economical choice for measuring objects up to three feet long.

Wood Rulers

A clear protective coating and brass endcaps add durability to these hard-maple rulers.

Nonslip Rulers

A cork back prevents slipping and protects delicate surfaces.

Starrett High-Accuracy Rulers

Also known as machinists’ rules, these rulers ensure reliable, repeatable measurements.

Starrett Certified High-Accuracy Rulers

Ensure reliable, repeatable measurements with these rulers.

High-Accuracy Rulers

An economical alternative to Starrett High-Accuracy Rulers, these provide reliable, repeatable measurements.

Certified High-Accuracy Rulers

These rulers include a certificate of calibration traceable to NIST with test measurements that confirm accuracy.

Starrett High-Accuracy Rulers with Hook

A reversible, removable hook grabs the edge of an object for easy alignment.

Scratch-Resistant High-Accuracy Rulers

Protect your ruler from scratches and wear with a TiN (titanium nitride) coating.

Magnetic High-Accuracy Rulers

High-powered magnets hold these rulers in place.

Adhesive-Back Rulers

Permanently mount these rulers to a machine or workbench.

Half-Measure Adhesive-Back Rulers

Use to find diameters and centers.

Pocket Rulers

Rulers are narrow, flexible and just 6" long to measure in tight, slightly curved spaces.

Folding Rulers

Fold these rulers for convenient storage and transport.

Long-Length Rulers

Create a ruler up to 192" long by adding continuous segments.

Cut-Protection Rulers

A safety guard or finger groove prevents your fingers from getting in the way as you cut with these rulers.

Vertical Rulers

Adhesive-Back Vertical Rulers

Permanently mount these rulers on machines, tanks, and walls to measure heights and depths.

Adhesive-Back Vertical Rulers for Floors

These extra-thick rulers have a polycarbonate coating that resists wear from traffic and chemicals.

Half-Measure Adhesive-Back Vertical Rulers

The graduations on these rulers are half the actual length of the object you are measuring.

Vertical Rulers

Measurements are printed from top to bottom for measuring heights and depths.

Long-Length Vertical Rulers

Use to measure heights and tank levels.

Vertical Rulers with Hook

A hook grabs the edge of an object for easy alignment.

Center-Finding Rulers

Zero marks the center when these rulers are positioned so the same number touches each side of an object.

Pocket Center-Finding Rulers

Slip these rulers into your pocket, so they’re always on hand to find center readings. All are narrow and about 6" long to measure in tight spaces.

Circumference Rulers

Determine the circumference of a circle without calculations.

Printers' Pica Rulers

Rulers are marked with picas for working with type.

Flexible Magnetic-Back Tape Measures

Flexible Magnetic-Back Tape Measure Sets

Attach to curved or flat steel surfaces.

Flexible Magnetic-Back Tape Measures

Attach to curved or flat steel surfaces.

Tank-Level Rulers

Built to resist corrosion and last in harsh environments, these vertical rulers are iron with a porcelain-enamel finish. Mount them to walls and tanks.

Tank-Level Folding Rulers

Fold these vertical rulers for convenient storage and transport.

Long-Length Tank-Level Rulers

Connect continuous segments to create a ruler up to 10 ft. long.

55-Gallon Drum-Level Rulers

Measure volume in gallons or liters without calculations.

Adhesive-Back Tank-Level Rulers

Permanently mount these vertical rulers to walls and tanks.

Squares

Squares with Graduations on Both Blades

Also known as carpenters’ and framing squares, these have graduations on both blades for horizontal and vertical measurements.

Squares

Also known as try squares, these are square inside and out for checking and marking angles.

Easy-to-Read Squares with
Graduations on Both Blades

Large numbers and dark graduations on both blades make it easy to read horizontal and vertical measurements.

Squares with Adjustable Blade

Measure and mark material exactly where you need to with a sliding blade.

Combination Squares

Replace your try square, miter square, depth gauge, marking gauge, 90° level, ruler, and scriber with one tool.

Heavy Duty Combination Squares

Built for welding and other heavy duty fabricating jobs, these squares have an extra-wide head and a large thumbwheel, so they’re easy to adjust and hold while wearing gloves. They combine the functionality of a try square, miter square, depth gauge, marking gauge, 90° level, and ruler in one tool.

Diameter Identifiers

Measure the outside diameter of small round- and hex-shaped objects such as rods, drill bits, bolts, and tubing with this pocket-size tool.

Straightedges and Drafting Rules

Rolling Parallel Rules

A rule, compass, protractor, and template all in one tool.

Architects’ and Engineers’ Scales

Take measurements off of scaled architectural or engineering drawings with these specialized scales.

T-Squares

Draw and cut straight lines in drafting, graphics, and construction applications.

Pocket Architects’ and Engineers’ Scales

Small enough to fit into your pocket, the blade is narrow and only 6" long. These scales are often used for taking measurements off scaled architectural or engineering drawings.

Magnifying Bars

These plastic bars have a magnified center; their edges are marked with graduations.

Levels with Rulers

Align and measure at the same time with these levels that have rulers.

Horizontal Rulers

Corrosion-Resistant Stainless Steel Rulers

Certified Corrosion-Resistant Stainless Steel Rulers

Certified Lightweight Aluminum Rulers

Lightweight Aluminum Rulers

Easy-to-Read High-Contrast Rulers

Easy-to-Read Rulers with Bold Markings

Transparent Rulers

Wood Yardsticks

Wood Rulers

Nonslip Rulers

Starrett High-Accuracy Rulers

Starrett Certified High-Accuracy Rulers

High-Accuracy Rulers

Certified High-Accuracy Rulers

Starrett High-Accuracy Rulers with Hook

Scratch-Resistant High-Accuracy Rulers

Magnetic High-Accuracy Rulers

Adhesive-Back Rulers

Half-Measure Adhesive-Back Rulers

Pocket Rulers

Folding Rulers

Long-Length Rulers

Cut-Protection Rulers

Vertical Rulers

Adhesive-Back Vertical Rulers

Adhesive-Back Vertical Rulers for Floors

Half-Measure Adhesive-Back Vertical Rulers

Vertical Rulers

Long-Length Vertical Rulers

Vertical Rulers with Hook

Center-Finding Rulers

Center-Finding Rulers

Pocket Center-Finding Rulers

Circumference Rulers

Circumference Rulers

Printers' Pica Rulers

Printers' Pica Rulers

Flexible Magnetic-Back Tape Measures

Flexible Magnetic-Back Tape Measure Sets

Flexible Magnetic-Back Tape Measures

Tank-Level Rulers

Tank-Level Rulers

Tank-Level Folding Rulers

Long-Length Tank-Level Rulers

55-Gallon Drum-Level Rulers

Adhesive-Back Tank-Level Rulers

Squares

Squares with Graduations on Both Blades

Squares

Easy-to-Read Squares withGraduations on Both Blades

Squares with Adjustable Blade

Combination Squares

Heavy Duty Combination Squares

Diameter Identifiers

Diameter Identifiers

Straightedges and Drafting Rules

Rolling Parallel Rules

Architects’ and Engineers’ Scales

T-Squares

Pocket Architects’ and Engineers’ Scales

Magnifying Bars

Magnifying Bars

Levels with Rulers

Levels with Rulers

Easy-to-Read Squares with
Graduations on Both Blades