Precision Grinding Machinist (NC/CNC)

Purpose of the Role

The Grinding Machinist is responsible for the final precision sizing of mold chases, and inserts. This role is the final gatekeeper of quality, ensuring that mating surfaces are perfectly flat, square, and finished to sub-micron tolerances to prevent flash in the molding process.

Key Responsibilities

• NC/CNC Operation: Set up and operate Mitsui (High-precision CNC surface grinders) and AMADA (surface grinders) to achieve critical dimensions.

• Surface & Profile Grinding: Execute precision surface grinding, step grinding, and complex profile grinding on hardened tool steels.

• Workholding & Alignment: Utilize magnetic chucks, sine plates, and precision vices to ensure workpieces are perfectly leveled and squared within 0.002mm.

• Wheel Dress Management: Select appropriate grinding wheels (CBN, Diamond, Aluminum Oxide) and perform precision dressing/truing for specific surface finish requirements.

• Heat Management: Monitor coolant flow and feed rates to prevent thermal distortion or surface burning of expensive mold components.

Job Requirements & Qualifications

Technical Expertise

• Machine Proficiency: 3-5 years of hands-on experience with Mitsui (e.g., MSG series) and AMADA (e.g., Techster or Meister series) NC/CNC grinding machines.

• Industry Background: Direct experience in Mold Chase fabrication or high-precision Plastic Injection Mold components.

• Tolerance Mastery: Proven ability to hold tolerances of 0.002mm on dimensions, flatness, parallelism, and squareness.

• Blueprint Reading: Expert ability to interpret mold assembly drawings and identify critical-to-function dimensions.

• Measurement: Proficient with high-accuracy tools like digital height gauges, micron-indicators, and optical comparators.

Preferred Skills

• Experience with CNC Grinding for complex mold and inserts.

• Knowledge of various Hardened HRC 55-60 tool steels (ASP 23, Elmax) and their grinding characteristics.

• Knowledge of various grinding wheel grade matching final finishing specs.