The Omega BT40 Test Arbor is a precision master mandrel designed for BT40 tooling, delivering a stable reference for tool holder alignment and fixture setup. It’s ideal for engineers, machinists, and workshop technicians who need reliable runout checks and repeatable setups in milling and turning environments.

Built to the BT MAS403 standard and compatible with JIS 6339, this 40 mm diameter test arbor features a long 300 mm gauge length for versatile use across multiple setups. The tapered nose and precision end ensure secure seating in BT40 holders, while a machined flat face with a central alignment hole provides a consistent reference reference point for checks and calibrations.

• Precise, repeatable reference: Delivers consistent measurements and alignment across setups, reducing guesswork and setup time.
• BT40, JIS 6339 compatibility: Seamlessly integrates with standard BT40 spindles and tooling, helping you avoid fitment issues and delays.
• Rugged, long‑lasting construction: Designed for daily shop use with durable machining quality, maintaining accuracy and reducing wear over time.

Using the BT40 Test Arbor helps you shorten setup cycles, verify spindle runout quickly, and keep fixtures aligned for repeatable, high-quality results. It’s a reliable reference that supports faster production, fewer reworks, and better consistency in every job.