In 1979, McDonald Machine was founded in Belmont, California near the heart of the Silicon Valley. This was during the onset of the technology revolution, where there was a high demand for tight tolerance, unconventional parts and assemblies. Based on the positive response we received from the different industries we machine for, we decided to incorporate in 1982 and relocated to Sonora, California.


By relocating, MMi was able to recruit, develop, and retain our talented and innovative employees from the surrounding communities. The foothills have given MMi the advantage of a lower cost of living and a better quality of life. The change allowed room for growth, coming from an 8,000 square foot building to our current 32,000 square foot, state-of-the-art manufacturing facility.


MMi aims to be your supplier of choice for high value added services. We are recognized as a leading provider of precision machined parts and components in assemblies and sub-assemblies. We are the partner of choice for outsourcing needs. 


Our success is based on our technical competence and quality performance. We prioritize R&D initiatives in order to keep us at the forefront of the manufacturing industry. Our customers will always have access to the most advanced technology available so that we are able to produce quality parts that meet your timeline and standards. 


We provide world class companies with machining services that make a positive contribution to their success by harnessing the enthusiasm and drive of our dedicated team.

Our Team


Shad Flores

Director of Sales and Marketing

With over 23 years of employment at MMi, Shad has excelled at several leadership positions within MMI over the years. As Director of Sales and Marketing He leads our company’s culture to reduce costs and align MMi's goals with our customers’ expectations. He provides tremendous industry experience to create solutions for our customers growing needs. His loyalty and commitment reflect our core values as a company in staying “committed to excellence.”

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Steve Woodward

Steve Woodward is responsible for the strategic leadership of the manufacturing team at MMi. Prior to joining MMI in 2008, Steve held a variety of Production Planning positions in the land development and home building industry where he oversaw and coordinated large teams through numerous multi-million-dollar projects on sensitive timelines. Steve holds a BS in Mechanical Engineering from Cal Poly, SLO.

Will McDonald

Vice President, Engineering

Will McDonald is responsible for the technical aspects of MMi's in-house and outside processes. He is passionate about keeping up with technical innovation and continually improving MMi’s capabilities and operations.  Prior to joining MMi, Will was a design engineer for a surgical robotics company. There, he designed/released numerous products to market, and holds patents pertaining to various surgical instruments. Will holds a BS in Mechanical engineering from Cal Poly, SLO.

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Mark Sommarstrom

Production Manager

Mark Sommarstrom is responsible for planning the shop-wide production schedule and communicating the delivery plan to our customers. With the use of MMi’s ERP system, and utilizing a very talented workforce, he constantly strives to meet and exceed customer demands. Mark has worked at MMi for 12 years holding a variety of past positions.  Mark's understanding of each customer's priorities is key to ensuring MMi’s services meet expectations.

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Alex Anderson

Production Manager

With over 20 years of experience in the precision machining industry Alex has been a go-to expert in Mills, Turning, and Swiss style lathes. Alex provides day to day strategy over each of our shop floor departments and responsible for processing parts through the shop according to the requirements and schedule. He manages agendas, anticipates roadblocks and helps sensitive projects get through the shop in a timely manner.

Joshua Milbourn

QC Manager

Joshua Milbourn has been involved in machining/Metal Manufacturing for over 30 years. He has been the Quality Manager at MMi since 2014 and was instrumental in MMi achieving ISO certification. Joshua is a key player in making sure MMi's standards are the highest possible and that MMi provides every customer with unyielding quality and reliability. 

Shelly Foley


Shelly Foley has been the Finance Manager at MMi since 2015, where she oversees all financial aspects and Human Resources at MMi. Shelly has worked in finance and accounting for almost 20 years, running her own accounting and bookkeeping business. She has a degree in Finance from Cal State Stanislaus .