Our castings are produced using the latest-generation Indutherm vacuum casting systems, equipped with vibration technology for flawless metal flow.

We pair this equipment with premium Italian alloys, creating exceptional metal density and eliminating micro-porosity — one of the most common problems in lower-grade production.

Every cast part is inspected under a microscope before moving to finishing and stone setting.

Dimensional accuracy, stone alignment, and structural performance are verified using high-precision SISMA equipment, trusted globally for jewelry measurement and laser applications.

Our quality checks include: exact tolerance verification for each model, prong geometry and stability control, seat depth and symmetry review, tension and security of every setting.

Each piece undergoes multi-stage polishing to achieve a mirror-like finish. Premium rhodium plating provides: long-lasting shine, enhanced resistance to wear, stable color tone, durability in fresh water, salt water, and active use.

We prioritize classic, structurally sound designs, avoiding unnecessarily complex settings that can compromise strength or long-term reliability. This approach ensures: optimal stone safety, long-term repairability, structural balance, aesthetic longevity.

Every AJO model is engineered to be both beautiful and durable for decades of use.

Step inside Four 9s Cluster, our U.S. jewelry production hub.