Starrett® 13 squares are very popular with machinists, toolmakers and patternmakers. The sliding blades are adjustable making it practical for a wide variety of uses. The faces of the head are ground square.

Starrett® Drill Grinding Blade, Series: 13 Series, 3 in Blade Length, Steel Blade, 1 Piece, Graduations: 64ths

• Sliding blades are adjustable
• Faces of the head are ground square
• Practical for a wide variety of uses
• Both ends have quick-reading 64ths grads and the graduation is located to measure perpendicularly to the axis of the drill
• By reading the graduations, the center point can be easily and accurately located
• For 6 in squares
• Beveled to 59 deg for drill grinding on one end and 41 deg the cutting angle of countersinks for machine screws at the other

• https://externalassets.unilogcorp.com/ASSETS/DOCUMENTS/ITEMS/EN/Starrett_13D_Full_Engineering_Drawing.pdf https://externalassets.unilogcorp.com/ASSETS/DOCUMENTS/ITEMS/EN/Starrett_13D_Full_Engineering_Drawing.pdf