Gibraltar 826821-G Shoulder Tooling Ball 0.5 in Press-fit

Product Description

The GIBRALTAR 826821-G is a shoulder-style inspection tooling ball used in precision fixturing and part-location applications on machine tools and coordinate measuring setups. The ball measures 0.5 inches in diameter with a 0.25-inch press-fit shank, and the ball center sits 0.5 inches above the shoulder bottom and 1.375 inches above the shank bottom. Manufactured from heat-treated steel, the part holds a ball-and-shank concentricity of 0.0002 inches, making it suitable for high-accuracy inspection and datum referencing work. A licensed machinist or tooling specialist typically installs and qualifies this component.

This tooling ball is intended for use in inspection fixtures, jigs, and precision workholding setups found in machine shops, aerospace fabrication cells, and general manufacturing environments. The shoulder design provides a positive, repeatable seating surface against a fixture body, allowing consistent ball-center positioning across multiple setups. The press-fit shank attachment keeps the ball firmly secured without threading. No specific equipment brand or model compatibility is stated by the manufacturer for this part.

Key Features

• Heat-treated steel construction for durability and dimensional stability
• 0.5-inch ball diameter with 0.0002-inch ball-and-shank concentricity tolerance
• 0.25-inch press-fit shank with a shank tolerance of +0.0003 / -0.0000 inches
• Shoulder design provides a positive seating datum against the fixture face
• Ball center to shoulder bottom: 0.5 inches; ball center to shank bottom: 1.375 inches
• Non-tapped, non-breakaway configuration for straightforward fixed-location use

Compatibility

Designed as an OEM-style precision tooling component for use in standard inspection fixture bores accepting a 0.25-inch press-fit shank; no specific equipment model compatibility is stated in the product data.

Installation Notes

Installation is typically performed by a tooling technician or machinist. The receiving bore must be machined to the correct press-fit tolerance before installation; do not force the shank into an undersized hole without verifying bore diameter. A press or arbor press is the recommended tool for seating the shank — avoid striking the ball directly. Verify ball-center height against fixture datums after installation before qualifying the fixture for production or inspection use.