Mechanical Engineer III

Therm-X, California; Hayward (CA); On-site; USD 90,000 - 120,000; Full time

Job summary

Therm-x in California seeks a Mechanical Engineer III to own mechanical design and 3D modeling for new assemblies, prototypes, and production. This hands-on role involves building and testing parts with machinists and technicians, iterating quickly when test data diverges from the model, and partnering with manufacturing, purchasing, and outside suppliers.

The ideal candidate will excel in SolidWorks, Inventor, or Solid Edge, read drawings and GD&T, and contribute to design reviews and

Qualifications

• Design experience for high-thermal/high-precision assemblies.
• Strong 3D modeling and GD&T interpretation.
• Ability to build and test prototypes in collaboration with shop floor.

Responsibilities

• Review customer requirements, BOMs, and drawings.
• Develop mechanical designs and 3D models for new assemblies.
• Prepare manufacturing drawings with GD&T.
• Author OMS and BOMs, plus work instructions.
• Estimate fabrication time and contribute to cost.
• Prototype build/test with machinists and NPI technicians.
• Lead design reviews and mentor junior engineers.

Skills

3D modeling

GD&T

SolidWorks

Prototype testing

Shop floor

Cross-functional

Mentoring

Tools

SolidWorks

Inventor

Solid Edge

FEA tools

Job description

Therm-x of California is the leading manufacturer for Advanced Temperature and Control Systems for Hi-Technology industries. We have been in business for over 30 years and have a diverse customer base. We offer competitive pay, and a comprehensive benefits package.

The Mechanical Engineer III is part of Therm-x's NPI Engineering team — the group that takes new heater, sensor, source, filter, junction, and cathode designs from customer concept through working prototype and into production. The role owns mechanical design and 3D modeling for assemblies with demanding thermal and mechanical performance requirements, builds and tests the first prototypes alongside our machinists and technicians, and partners with manufacturing, purchasing, and outside suppliers so that what is designed is what we can build.

This is a hands-on role. The strongest engineers on this team spend real time in the shop, learn how the parts they design are actually machined, brazed, and assembled, and iterate fast when test data does not match the model. We are looking for engineers who want to design, build, test, and improve.

Responsibilities and Duties:

• Review customer requirements: BOMs, 2D & 3D drawings, specifications, and acceptance criteria.
• Develop mechanical designs and 3D models (SolidWorks, Inventor, or Solid Edge) for new assemblies and product variants.
• Prepare manufacturing drawings, including pre-braze / pre-weld details, GD&T callouts, and finished-part drawings.
• Author OMS (Operational Method Sheets): manufacturing process flow, BOM, and work instructions.
• Estimate part fabrication and assembly time; contribute to materials and labor costing.
• Build and test prototypes hands‑on, working directly with the prototype machinist, NPI technicians, and the production shop.
• Run prototype testing (thermal cycling, thermal uniformity, dimensional, and functional) and document findings.
• Produce First Article Inspection (FAI) reports and own ECR/ECO redlines through the change cycle.
• Track project timeline, cost, and risks; keep the project on budget and on schedule; elevate early when it is not.
• Spend time on the shop floor. Solicit input from machinists, operators, and quality, and carry that feedback into the next design revision.
• Level III & SR
  • Lead full mechanical design for new product families, including stress and thermal analysis.
  • Own supplier interfaces for machined and brazed parts; negotiate cost and delivery to meet customer requirements.
  • Run formal design reviews and contribute to customer proposals and technical content.
  • Mentor Level I and II engineers; review their drawings and FAIs before release.
  • Build and maintain reusable design libraries, templates, and analysis methods so the team gets faster over time.

Desired Skills;

• Strong 3D modeling — SolidWorks, Autodesk Inventor, or Solid Edge — including assemblies, configurations, and drawings with GD&T.
• Ability to read and interpret assembly drawings, blueprints, and basic electrical schematics.
• Thermal application experience — heater systems, temperature sensing, or thermal management. Familiarity with brazing, welding, and ceramics is a strong plus.
• Strong written communication: clear drawings, FAIs, and technical memos.
• Project management discipline: schedule, cost, and risk tracked weekly.
• Hands‑on by default. Comfortable in safety glasses on a CNC mill, lathe, or assembly bench.
• Collaborative with machinists, operators, purchasing, and customers. Treats shop-floor feedback as a primary input, not an interruption.
• Curious and learns fast. Therm-x's product mix is broad, and the strongest engineers build a deep mental model of how our products work in our customers' tools.
  • Thermal and structural FEA — COMSOL preferred for thermal; ANSYS or Inventor Stress acceptable for mechanical.
  • Electrical drafting capabilities — AutoCAD Electrical (ACADE) or equivalent is a plus.
  • Working knowledge of SPC, lean manufacturing, Six Sigma, and 8D problem-solving.
  • Ability to lead design reviews and mentor junior engineers.

Physical Demands:

While performing the duties of this Job, the employee is regularly required to stand; walk; si; use hands to finger, handle, or feel; reach with hands and arms; climb or balance; stoop, kneel, crouch, or crawl; talk or hear and taste or smell. The employee must occasionally lift and/or move up to 30 pounds.