Precision Squares | McMaster-Carr

	System of Measurement System of Measurement

Inch

Metric

	Blade Length Blade Length

	Blade Width Blade Width

	Blade Thickness Blade Thickness

	Material Material

Steel

Iron

	Angle Measured Angle Measured

30°

45°

90°

	DFARS (Defense Acquisition Regulations Supplement) DFARS (Defense Acquisition Regulations Supplement)

DFARS Specialty Metals
COTS-Exempt

	Graduation Marks Graduation Marks

	Manufacturer Model Number Manufacturer Model Number

	Length Length

	Component Component

Blade

Square Head with Built-in
Level

Square Head

Center Head

Nonreversible Protractor
Head with Built-in Level

Reversible Protractor Head

Reversible Protractor Head
with Built-in Level

	Specifications Met Specifications Met

Fed. Spec. GGG-S-656-E

Fed. Spec. GGG-R-791H

	Square Head Material Square Head Material

Iron

Steel

	Numeric Increments Numeric Increments

1/10"

8/64"

10 mm

	Graduation Location Graduation Location

Back

Front

	Blade Color Blade Color

	Silver
	Gold

	Head Length Head Length

	Width Width

5/8"

3/4"

	Thickness Thickness

1/16"

5/64"

3/32"

	Protractor Head Material Protractor Head Material

Cast Iron

Hardened Cast Iron

	For Maximum Blade Length For Maximum Blade Length

24"

48"

	Center Head Material Center Head Material

117 Products

Squares

High-Accuracy Squares

Ensure reliable, repeatable angles.

High-Accuracy Square Sets

Ensure reliable, repeatable angles.

Starrett High-Accuracy Squares

These squares meet Fed. Spec. GGG-S-656-E, which establishes uniform standards for square accuracy to ensure reliable, repeatable angles.

Squares with Adjustable Blade

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

Combination Squares

Starrett High-Accuracy Combination Squares

Replace your try square, miter square, depth gauge, height gauge, center-point finder, and level. The blade on these squares meets Fed. Spec. GGG-R-791H, which establishes uniform standards for accuracy, graduations, and size.

Starrett High-Accuracy Combination Square Blades

Use these blades with Starrett High-Accuracy Combination Square Heads. They meet Fed. Spec. GGG-R-791H, which establishes uniform standards for accuracy, graduations, and size.

Starrett High-Accuracy Combination Square Heads

Attach to Starrett High-Accuracy Combination Square Blades with the included lockbolts.

High-Accuracy Combination Square Heads

Attach to High-Accuracy Combination Square Blades with the included lockbolts.

High-Accuracy Combination Squares

Use these squares in place of your try square, miter square, depth gauge, height gauge, center-point finder, and level.

High-Accuracy Combination Square Blades

Blades are for use with High-Accuracy Combination Square Heads.

Scratch-Resistant High-Accuracy Combination Squares

A titanium coating protects the blade against scratches and wear.