Starrett 56373 Combination Square Set 18 in 3 Pc

Product Description

The STARRETT 56373 is a 3-piece combination square set built for layout, inspection, and measurement work in the trades and light fabrication. The set includes an 18-inch steel blade graduated in 16R style, meaning the blade carries four graduation scales: 1/32, 1/64, 1/100, and 1/50 inch. Two heads are included: a standard square head and a center square head, both cast iron. This combination gives the technician or tradesperson a single kit capable of scribing 45- and 90-degree angles, finding the center of round stock, and verifying flat and square surfaces across a wide range of layout tasks.

This set is suited for use by HVAC sheet metal fabricators, pipefitters, electricians, and general maintenance technicians who perform layout and fit-up work on the job or at a shop bench. The 18-inch blade length accommodates wider stock and longer layout runs than a standard 12-inch set. The cast iron heads provide mass and stability during scribing. The 16R graduation style is a common shop standard, compatible with typical machinist and trade workflows where both fractional and decimal inch readings are required at the blade.

Key Features

• 18-inch steel blade with 16R graduation in 1/32, 1/64, 1/100, and 1/50 inch scales
• Cast iron square head for 90-degree and 45-degree layout and depth measurement
• Cast iron center square head for locating centers on cylindrical or round stock
• 3-piece set covers standard squaring, angle, and center-finding tasks in one kit
• Steel blade construction resists flex during extended layout use

Compatibility

Designed as a standard 18-inch combination square set suitable for general trade layout and inspection work where 16R-graduated blades and cast iron heads are required.

Installation Notes

Combination squares are hand-layout tools and require no installation in the traditional sense. Secure the head firmly on the blade before use to prevent slippage during scribing. Keep the blade and head contact surfaces clean and free of burrs or debris to maintain accurate 90-degree registration. Store the set protected from impact to preserve blade graduation legibility and head squareness over time.