Starrett 56397 Combination Square Set 12 in 3 Piece

Product Description

The STARRETT 56397 is a 3-piece combination square set built for layout, inspection, and measurement work in the field or shop. The set includes a 12-inch steel blade paired with a square head and a forged steel center square head, giving technicians and tradespeople the tools to check squareness, find centers, and mark precise lines in a single kit. The blade features 4R graduation, providing four scales: 1/16, 1/32, 1/64, and 1/8 inch, covering the range of precision required for most mechanical, plumbing, and HVAC fabrication tasks. The forged steel construction on the center head adds durability under repeated job-site use.

This combination square set is suited for residential and light commercial trade work where accurate layout and measurement are required. Typical applications include marking cut lines on sheet metal ductwork, checking squareness on equipment mounting surfaces, finding center points on pipe or conduit, and general layout on structural components. The compact 12-inch blade length fits standard workbench and field use without the bulk of larger measuring instruments. HVAC sheet metal fabricators, plumbers, electricians, and general mechanical contractors are the primary installers and users of this tool.

Key Features

• 3-piece set includes 12-inch steel blade, square head, and forged steel center square head
• 4R graduation system: 1/16, 1/32, 1/64, and 1/8 inch scales on a single blade
• Forged steel center square head for durability and accurate center-finding
• Steel blade construction resists flex and wear through repeated use
• Metric-equivalent graduations of 0.02, 0.03, 0.06, and 0.13 inch increments for cross-reference work

Compatibility

Designed as a standard 12-inch combination square set suitable for general trade measurement and layout tasks across HVAC, plumbing, electrical, and mechanical applications.

Installation Notes

This is a hand tool requiring no installation. Keep the blade and head locking mechanism clean and free of metal shavings or debris to maintain accurate blade positioning. Periodically check the square head for true 90-degree reference against a known flat surface. Store in a dry environment to prevent blade corrosion and protect graduation markings.