Gibraltar 826816-G Shoulder Tooling Ball 1/2 in Press-fit

Product Description

The GIBRALTAR 826816-G is a shoulder-style inspection tooling ball designed for precision fixturing and gauging applications in machining and metrology environments. It features a 0.5-inch ball diameter and a 0.25-inch shank diameter with a press-fit attachment type, allowing secure, repeatable installation into fixture plates and jig bodies. The ball is heat-treated steel, providing hardness and wear resistance suited to repeated use in high-contact inspection setups. Ball-to-shank concentricity is held to 0.0002 inches, ensuring accurate reference-point repeatability. The shoulder design establishes a positive stop during installation, controlling ball center height to a consistent 0.4 inches from the shoulder bottom.

This tooling ball is used in tool rooms, CMM fixturing, and production inspection setups where a precise, repeatable datum point is required. The press-fit shank installs into standard 0.25-inch reamed holes in steel or aluminum fixture plates. The shoulder-stop feature eliminates the need for separate spacers to set ball centerline height. Machinists, toolmakers, and quality technicians working in jig-and-fixture or dimensional inspection environments are the primary installers. It ships in a quantity of one per package.

Key Features

• 0.5-inch ball diameter with 0.0002-inch ball-to-shank concentricity for high-accuracy reference points
• Shoulder design provides a positive installation stop, setting ball center 0.4 inches from shoulder bottom
• Press-fit 0.25-inch shank with shank tolerance of +0.0003 / -0.0000 inches for consistent fit in reamed holes
• Heat-treated steel construction for hardness and long service life in contact-wear environments
• Ball center to shank bottom dimension of 15/16 inch (0.9375 inches) for predictable fixture geometry
• No tapped shank or breakaway feature — fixed, permanent-installation design

Compatibility

Designed for press-fit installation into standard 0.25-inch reamed holes in fixture plates, jig bodies, and CMM tooling systems requiring a shoulder-style inspection datum ball.

Installation Notes

Installation is performed by toolmakers or metrology technicians using a press or arbor press to seat the shank into a precision-reamed 0.25-inch hole. Ensure the receiving hole is reamed to the appropriate tolerance to accept the press-fit shank without damage to the ball or bore. The shoulder must seat flush against the fixture surface to achieve the specified ball centerline height. Do not drive the ball using the sphere itself, as this may deform the ball or affect concentricity.