A Japanese manufacturer of dental equipment had been purchasing generic, off-the-shelf gears from catalog suppliers, then machining each piece in-house to meet their precise drawing specifications. After learning about powder metallurgy's ability to produce custom parts directly to print, they partnered with Yeh Sheng to redesign their supply chain.
Off-the-shelf gears were only "close" to the required dimensions. Every piece needed secondary CNC machining to achieve the tight tolerances required for dental handpiece mechanisms.
Each gear required individual setup, fixturing, and CNC machining time — a costly process especially for the small batch quantities typical in dental equipment manufacturing.
Different batches of off-the-shelf gears had slight variations in material and dimensions, leading to unpredictable results after machining. This made quality control difficult for a medical-grade product.
Managing inventory of raw gears, scheduling CNC machining time, and coordinating inspection created unnecessary overhead for a component that should simply arrive ready to assemble.
Yeh Sheng's engineering team designed a dedicated PM die based on the customer's exact gear drawings, accounting for sintering shrinkage to achieve the final dimensions directly from the press.
Gears are pressed and sintered to near-final dimensions with tolerances of ±0.02mm. Only minimal secondary operations like tapping remain — eliminating the bulk of CNC machining previously required.
Yeh Sheng specializes in small-batch, high-variety production — a perfect match for dental equipment manufacturers who need multiple gear variants in quantities of hundreds, not thousands.
Every gear is produced from the same controlled powder formulation with SPC-monitored weight and dimensional consistency — critical for medical device traceability requirements.
By switching from "buy generic + machine to fit" to "custom PM from drawing," the customer simplified their supply chain from a multi-step process to a streamlined solution. Parts now arrive near-net shape with only minimal finishing (e.g., tapping) needed — dramatically reducing machining time, rework, and quality variability.