Starrett CB12-4R Satin Chrome Combination Square Replacement Blade Graduation - 12-Inch 4R

The Starrett CB12-4R is a precision replacement blade designed for use with Starrett combination squares, combination sets, and bevel protractors. Crafted from hardened and tempered steel with a photo-engraved satin chrome finish, this 12-inch blade delivers glare-free readability and long-lasting durability in demanding shop environments.

The 4R graduation provides four scales on a single blade — 8ths, 16ths, quick-reading 32nds, and 64ths of an inch — giving machinists, toolmakers, woodworkers, and metalworkers the fine measurement resolution they need for accurate layout and inspection work.

Key Features:

• Blade Length: 12 inches
• Graduation Type: 4R — 8ths, 16ths, quick-reading 32nds, and 64ths
• Blade Material: Hardened and tempered steel
• Blade Finish: Satin chrome (reduces glare for easy reading)
• Blade Dimensions: Approximately 1" wide x 3/32" (0.094") thick
• Photo-engraved graduations for precise, permanent markings
• Compatible with any 4" head combination square, combination set, or bevel protractor
• Interchangeable with 12", 18", 24", 36", 48", 300mm, and 600mm Starrett blades
• Note: Not compatible with Starrett models 33J and 8 combination squares
• Made in the USA

This blade is an ideal replacement or spare for any Starrett combination set and is sold individually (blade only — head not included). The Starrett CB12-4R meets the accuracy and performance standards expected of Starrett precision measuring tools, making it a reliable choice for industrial, professional, and shop use.