Introduction: Why the Pipette Tip Core Is a Medical-Grade Discipline

The pipette tip core (吸液头型芯) forms the conical bore of every disposable tip used in diagnostics and liquid handling. A few microns of deviation changes the dispense volume; a rough surface traps residue and fails cleaning validation. For mould makers, this is where precision and cleanliness stop being marketing words and become quantified requirements.

This article walks through how a medical-grade tip core is actually made — from tolerance budgeting to mirror polishing.

1. Tolerance Budgeting: Where the Microns Go

A multi-cavity tip mould demands that every cavity dispenses within spec. The core controls the bore diameter and taper, so its concentricity and straightness must be held to roughly ±0.002 mm, while the cavity insert sets the outer wall. SHENGQI budgets these at the DFM stage using mold-flow and tolerance-stack analysis rather than adjusting after trial.

2. Material and Heat Treatment

For medical tips, cores are typically SKD61 or S136 (mirror-grade stainless). S136 is preferred where corrosion resistance and a Ra≤0.05 µm mirror finish are required. Vacuum heat treatment avoids surface decarburization, and a stress-relief tempering cycle stabilizes the geometry before final grinding.

3. Medical-Grade Polishing and Verification

Polishing follows a stepped sequence (rough grind → fine grind → diamond paste) to reach a contamination-free, low-adhesion surface. Each core is verified on ZEISS / HEXAGON CMMs (±0.0015–0.0022 mm) and roughness testers. With ISO 13485 certification, the process is documented for traceability — important for audits in diagnostic and pharmaceutical supply chains.

4. Why This Matters for Buyers

A well-made tip core reduces rejected tips, balances fill across cavities and shortens validation. SHENGQI PRECISION has supplied medical mould components for 21+ years and serves customers such as Mindray and Weigao. Two bases (Dongguan + Huangshi, 40,000 m²), 330+ machines and ISO 9001 / 13485 / 14001 backing support stable, compliant delivery.

Need high-precision medical pipette tip cores? Contact SHENGQI PRECISION — Jason Wong, +86 13652919880, jasonwong@shengqi.com, www.dgshengqi.com.