Engineer I, Mechanical

MP Materials Corp.•Mountain Pass, CA

3d•$120,000 - $150,000•Onsite

About The Position

MP Materials (NYSE: MP) is rebuilding American industrial capability for a new era of autonomy, robotics, and electrification. We are the only U.S. company with a fully integrated rare earth supply chain—from mining and refining to advanced metal and magnet manufacturing. Our products include both the critical materials used to make permanent magnets and the finished magnets themselves—enabling next-generation technologies in robotics, automation, aerospace, transportation, defense, and energy systems. These materials are the foundation of physical AI—the convergence of computation, movement, and control. We hire ambitious, mission-driven people who want to tackle complex challenges and shape the future of strategic industries. Our culture is rooted in teamwork, resiliency, and integrity, with a deep commitment to operational excellence and national purpose. MP is rapidly evolving from a materials producer into a leading U.S. manufacturer—and our people are driving that transformation. We are seeking a highly skilled and experienced Senior Mechanical Engineer to join our team. As a Senior Mechanical Engineer, you will play a critical role in supporting the design, operation, maintenance, and continuous improvement of mechanical systems and equipment across our industrial facilities. You will be responsible for providing technical expertise, troubleshooting complex equipment issues, and driving initiatives that improve safety, reliability, efficiency, and overall plant performance. The ideal candidate will have a strong background in mechanical engineering, heavy industrial equipment, project management, and operational support. This position requires collaboration with operations, maintenance, engineering, and contractor teams to develop practical solutions that enhance equipment performance and support business objectives.

Requirements

Bachelor's degree in engineering, preferably in mechanical or industrial engineering.
Strong knowledge of mechanical equipment design, maintenance, and operation, including rotating equipment, piping systems, hydraulic systems, conveyors, pumps, tanks, and structural systems.
Proficiency in engineering design principles, engineering calculations, and interpretation of mechanical drawings and specifications.
Knowledge of applicable engineering codes and standards, including ASME, ANSI, API, AISC, and other relevant industry standards.
Knowledge of industry standards and regulations related to asset reliability, safety, and compliance.
Excellent communication and interpersonal skills, with the ability to effectively collaborate with cross-functional teams and present findings to stakeholders.

Responsibilities

Provide mechanical engineering support for plant operations, maintenance, and capital projects to ensure safe, reliable, and efficient operation of mechanical equipment and systems.
Lead the design, specification, evaluation, and implementation of mechanical equipment, including pumps, piping systems, conveyors, crushers, rotating equipment, tanks, pressure systems, structural components, and process equipment.
Develop engineering scopes of work, technical specifications, equipment standards, and bid packages for maintenance and capital improvement projects.
Troubleshoot and resolve complex mechanical equipment failures and operational issues through engineering analysis, field investigations, and root cause analysis.
Collaborate with operations and maintenance teams to identify opportunities for equipment improvements, process optimization, energy reduction, and cost savings.
Review and approve engineering drawings, calculations, equipment designs, vendor submittments, and construction packages to ensure compliance with company standards and applicable codes.
Provide technical leadership for equipment upgrades, plant expansions, modernization efforts, and continuous improvement initiatives.
Support preventative maintenance and equipment inspection programs by providing engineering recommendations for equipment life extension, repair strategies, and replacement planning.
Conduct field assessments and engineering studies related to equipment performance, system capacity, vibration, wear, corrosion, structural integrity, and operational efficiency.
Ensure compliance with applicable safety regulations, environmental requirements, engineering standards, and company policies.
Participate in risk assessments, management of change (MOC) processes, incident investigations, and hazard reviews to improve operational safety and reduce risk.
Develop technical reports, engineering calculations, project justifications, and presentations for plant leadership and stakeholders.