Starrett 51559 Combination Square Set 24 Inch 4 Piece

Product Description

The STARRETT 51559 is a 4-piece combination square set built for layout, inspection, and measurement work on the job site or in the shop. The set includes a 24-inch steel blade paired with three interchangeable cast iron heads: a square head, a center head, and a protractor head. The blade is graduated in 4R style, providing four graduation scales: 1/64 inch, 1/32 inch, 1/16 inch, and 1/8 inch on a single blade. This range of graduations supports both rough layout and fine measurement tasks. Licensed tradespeople and skilled machinists working in plumbing, HVAC, electrical, or general fabrication will find this set serviceable across a wide range of layout applications.

This combination square set is suited for residential and commercial trade work where precise layout and transfer measurements are required. The square head is used for 90-degree and 45-degree layout and depth measurement. The center head locates the center of round stock. The protractor head allows angle measurement and layout. The 24-inch blade length accommodates larger workpieces common in mechanical, fabrication, and sheet metal work environments.

Key Features

• 4-piece set includes square head, center head, and protractor head with one 24-inch steel blade
• 4R graduation style with four scales: 1/64, 1/32, 1/16, and 1/8 inch
• Steel blade construction for durability and dimensional stability
• Cast iron head construction for rigidity and wear resistance
• Interchangeable heads allow one blade to serve multiple measurement functions
• 24-inch blade length suits larger layout tasks in fabrication and sheet metal work

Compatibility

Designed as a standard combination square set compatible with general layout and inspection tasks across trade and fabrication applications. No specific system or model compatibility was stated in the product data.

Installation Notes

Combination square sets require no installation. Handle the cast iron heads with care to prevent chipping, which can affect squareness accuracy. Store the blade separately from abrasive surfaces to maintain graduation legibility. Periodically verify the square head against a known reference surface to confirm accuracy over time.