Starrett 56407 Combination Square Set 24 in 3 Pc

Product Description

The STARRETT 56407 is a 3-piece combination square set built for precise layout and inspection work across a range of trade and fabrication applications. The set includes a 24-inch steel blade graduated in 16R style, meaning the blade carries four graduation scales: 1/100, 1/32, 1/50, and 1/64 inch. Two heads are included: a square head and a forged steel center square head. The square head allows standard 45- and 90-degree reference, while the center square head is used to locate the center of round stock. This set is appropriate for machinists, pipefitters, ironworkers, and layout technicians who need reliable, readable measurement tools on the job.

This combination square set suits precision layout tasks in industrial, fabrication shop, and trade environments. The 24-inch blade length accommodates larger workpieces where a standard 12-inch square falls short. The 16R blade graduation is a widely used scale pattern that supports both fractional and decimal inch measurement, making it adaptable across blueprint styles. The forged steel center square head is especially useful when locating shaft centers or marking out circular cross-sections before drilling or turning operations.

Key Features

• 24-inch steel blade with 16R graduation pattern (1/100, 1/32, 1/50, and 1/64 inch scales)
• Includes both a square head and a forged steel center square head
• Forged steel center square head for durable, accurate center-finding on round stock
• Steel blade resists flex and maintains straight edge integrity over repeated use
• 3-piece configuration covers both 90/45-degree layout and center-finding in a single set

Compatibility

Designed as a standard combination square set compatible with typical layout and inspection workflows requiring a 24-inch blade with 16R graduation; heads are compatible with the included blade per the set configuration.

Installation Notes

Combination squares require no installation but should be handled and stored carefully to preserve blade straightness and head lock integrity. Periodically verify the square head is reading true 90 degrees against a known reference surface, as lock nuts can loosen with heavy use. Keep the blade clean and lightly oiled to prevent surface rust, which can obscure graduation markings. This tool is not a cutting guide — do not use it as a straightedge against a power saw blade without appropriate fixturing.