Starrett 51546 Combination Square Set 24 Inch 4 Piece

Product Description

The STARRETT 51546 is a 4-piece combination square set built around a 24-inch steel blade with 4R graduation. The 4R graduation system provides four scales — 1/16, 1/32, 1/64, and 1/8 inch — giving layout and measurement flexibility across precision trade work. The set includes three interchangeable heads: a square head, a center head, and a protractor head, all constructed from forged steel for durability under job-site conditions. The blade is steel with clear, accurate markings suited for repeated scribing and transfer work. This set is used by pipefitters, millwrights, machinists, electricians, and general trade contractors who need reliable layout tools.

The STARRETT 51546 combination square set is appropriate for residential and commercial construction, mechanical rooms, fabrication shops, and service environments where precise layout, angle measurement, and center-finding are routine tasks. The 24-inch blade length suits structural layout as well as equipment alignment. The protractor head allows direct angle setting without a separate tool, and the center head locates center points on round stock quickly. Each head locks firmly to the blade for consistent measurements across a job.

Key Features

• 4-piece set includes square head, center head, and protractor head plus 24-inch steel blade
• 4R graduation provides 1/16, 1/32, 1/64, and 1/8 inch scales on a single blade
• Steel blade — 24 inches in length — suitable for structural and equipment layout
• Forged steel heads for strength and resistance to job-site wear
• Protractor head enables direct angle measurement without a secondary tool
• Center head locates center on cylindrical or round stock

Compatibility

Designed as a standard 4R-graduation combination square set compatible with typical trade layout and measurement applications requiring a 24-inch blade.

Installation Notes

No power source or shutoff is required for layout tools of this type. Verify blade lock tightness before scribing to prevent slippage that could affect measurement accuracy. Store the set with heads removed from the blade when not in use to preserve graduation markings and head seating surfaces. Inspect the blade for burrs or bends before use, as blade distortion will affect reading accuracy.