Starrett 50578 Adjustable Parallel 3/8 to 1/2 Inch Steel

Product Description

The STARRETT 50578 is a steel adjustable parallel designed for precision layout, inspection, and machining work. It spans a measurement range of 3/8 inch to 1/2 inch, making it suited for setting up close-tolerance work in milling, grinding, and inspection applications. The parallel measures 1-3/4 inches in length and 9/32 inch in thickness, providing a compact and stable reference surface. At 0.125 pounds, it is lightweight enough for repeated handling in production environments. Machinists, toolmakers, and precision measurement technicians are the primary users of this type of tooling.

Adjustable parallels like the 50578 are used in machine shops and tool rooms where workpieces must be supported or referenced at specific heights during setup. They are commonly placed under workpieces on surface plates, in vises, or on machine tables to achieve accurate, repeatable positioning. The 3/8 to 1/2 inch range targets smaller workpieces and fine-tolerance setups where fixed parallels do not provide enough flexibility. This part is suited for both job shop and production environments where setup time and measurement accuracy are critical.

Key Features

• Adjustable range from 3/8 inch to 1/2 inch (approximately 9.525 mm to 12.70 mm)
• Steel construction for durability and dimensional stability
• Compact size: 1-3/4 inches long by 9/32 inch thick
• Lightweight at 0.125 pounds for easy single-hand use during setup
• Suitable for use on surface plates, in vises, and on milling or grinding machine tables

Compatibility

Designed as an OEM-style adjustable parallel for general precision machining and inspection setups requiring a measurement range of 3/8 to 1/2 inch.

Installation Notes

Adjustable parallels are set and used by machinists and toolmakers during workpiece setup; no permanent installation is required. Keep contact surfaces clean and free of chips or debris before use to maintain accurate referencing. Handle with care to avoid nicks or burrs on the working surfaces, which would affect measurement accuracy. Store in a dry environment to prevent corrosion of the steel surfaces.