CNC Mill Programmer & Machinist

Woodbridge, ON (On-site) · Full-time · Machining · Experience: 5+ years

You will program, set up, and run our CNC milling machines to produce precision components that meet tight tolerances and customer specifications. Each job runs from the engineering drawing or 3D model through Mastercam programming, setup, first-article inspection, and finished parts.

Setup is a big part of this role. Most of our jobs are one-offs and short runs, so you will set up each job yourself, machine a first piece to prove out the program, check it against the drawing, and fine-tune the program and offsets before running the rest.

Our work is a steady mix of prototypes, one-offs, tooling, and short production runs in aluminum, stainless steel, and tool steels. You will work closely with the owner-engineer and the design team on workholding, sequence, and machinability, and you will be trusted to decide how a part should be made.

What you will do

CNC mill programming

Develop and edit CNC milling programs in Mastercam, with direct G-code editing at the machine.
Translate engineering drawings and 3D models into efficient toolpaths.
Optimize machining strategies for precision, efficiency, and repeatability.

Setup and operation

Set up CNC mills with the right tooling, fixturing, and work offsets.
Prove out every new program: dry-run it, machine a first piece, inspect it against the drawing, and adjust the program or offsets before running the rest of the job.
Handle frequent changeovers between one-off, prototype, and short-run jobs, keeping setups efficient and repeatable.
Run production jobs while monitoring tool wear, chip load, and part quality.
Adjust machine parameters and tool offsets as required.

Quality assurance

Measure and inspect parts with calipers, micrometers, gauges, and height indicators.
Make sure finished components conform to drawing tolerances and surface finish standards.
Document measurements and maintain inspection records for traceability.

Maintenance and troubleshooting

Perform routine maintenance on CNC milling machines.
Troubleshoot issues such as tool breakage, chatter, and dimensional inconsistencies.
Recommend process or tooling improvements that reduce setup time or improve output.
Keep a clean and organized work area in line with shop standards.

Grinding, as needed

Operate manual or surface grinders for precision finishing where required.
Set up grinding tools and verify results against tolerances and visual standards.

What you bring

5+ years of experience programming and operating CNC milling machines.
Proficiency in Mastercam and G-code editing.
Ability to interpret detailed engineering drawings and GD&T.
Solid understanding of material behaviour and machining principles, including speeds and feeds and tool selection.
Experience machining aluminum, stainless steel, and tool steels.
Familiarity with ISO tolerancing and standard inspection practices.

Nice to have

Surface grinding experience.
Experience in a job shop, tool and die, or other high-mix, low-volume environment.
Familiarity with ISO 9001 or AS9100 quality systems.
Russian or Ukrainian language skills.

About MAS Precision Parts

MAS Precision Parts has machined custom, tight-tolerance parts in Woodbridge, Ontario since 1989. We are a small job shop serving automotive, aerospace, food processing, and construction customers, with work that runs from one-off prototypes and repairs through tooling and short production runs. The floor covers CNC milling and turning, manual machining, Wire EDM, and surface and jig grinding, so the work is varied and you see parts through from drawing to delivery.

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