Spi 13-278-7 Combination Square Set 18 in 4 Piece

Product Description

The SPI 13-278-7 is a 4-piece combination square set built for layout, measurement, and inspection work across mechanical, fabrication, and trade applications. The set includes a square head, center head, and protractor head, all paired with a hardened steel blade measuring 18 inches in length. Graduations follow the 16R standard, providing readings in 1/100, 1/32, 1/50, and 1/64 inch increments. The cast iron heads deliver the mass and rigidity needed for accurate, repeatable readings on the bench or in the field. Licensed tradespeople, machinists, and installation technicians rely on this class of tool for precise angle transfer and scribe work.

This combination square set is suited for sheet metal layout, mechanical assembly, HVAC equipment installation, and general fabrication tasks where multiple head configurations are needed in a single kit. The protractor head handles angle measurement and transfer, the square head covers 90-degree and 45-degree references, and the center head locates center points on cylindrical stock. The 16R graduation style makes it compatible with standard machinist and trade layout workflows used in both residential and light commercial environments.

Key Features

• 4-piece set includes square head, center head, and protractor head with one 18-inch blade
• Hardened steel blade resists wear and maintains graduation accuracy over repeated use
• Cast iron heads provide stability and resistance to racking during measurement
• 16R graduation style: 1/100, 1/32, 1/50, and 1/64 inch increments on a single blade
• Protractor head enables direct angle measurement and transfer without a separate tool
• Center head locates centerlines on round and square stock quickly

Compatibility

Designed as a general-purpose combination square set compatible with standard 18-inch blade layout and inspection workflows across mechanical, fabrication, and trade installation applications.

Installation Notes

This tool is used by tradespeople and machinists for layout and inspection rather than permanent installation. Before use, verify the blade lock mechanism seats fully and the head is flush with the reference surface to ensure accurate readings. Store the set in its case when not in use to protect graduation markings on the blade from damage. No power isolation is required for use of this tool, but follow standard shop safety practices when working near energized equipment or rotating machinery.