Spi 13-459-3 Combination Square Blade 24 Inch 4R

Product Description

The SPI 13-459-3 is a 24-inch replacement blade for combination squares, designed for layout, inspection, and measurement work in trades and manufacturing environments. The blade features a 4R graduation pattern with four scales: 1/64, 1/32, 1/16, and 1/8 inch, giving technicians and machinists the resolution they need for precise scribing and transfer measurements. A baked enamel coating protects the graduation markings from wear and chemical exposure common in shop environments. The blade weighs approximately 1 pound and is sold individually.

This blade is suited for use in metalworking shops, fabrication facilities, HVAC sheet metal work, plumbing rough-in layout, and general construction trades where a combination square is part of the standard tool kit. It is a direct replacement blade intended for use with combination square heads that accept a 24-inch blade. Professionals who regularly perform layout work on flat stock, pipe, or structural members will find the four-scale 4R graduation useful for working across different measurement systems without switching tools.

Key Features

• 24-inch blade length for extended layout reach
• 4R graduation with 1/64, 1/32, 1/16, and 1/8 inch scales
• Baked enamel coating protects markings from abrasion and shop fluids
• Sold as a single blade replacement unit
• Approximately 1 pound — lightweight enough for one-hand positioning

Compatibility

Designed as a replacement blade for combination squares that accept a standard 24-inch blade. Confirm head slot width and locking mechanism compatibility with your existing combination square before ordering.

Installation Notes

Blade replacement on a combination square requires loosening the locking screw on the square head and sliding the old blade free from the groove. Insert the new blade and re-engage the locking mechanism before use. No special tools or trade licensing are required, but always verify blade seating and lock engagement before applying measurement force to avoid inaccurate readings or blade slippage.