JANUARY 2021 – NEW OWNERSHIP

We are excited to announce Joseph and Amanda Otterstrom as the new owners of Terra Diamond and GDM Equipment.

Terra Diamond, LLC merges Terra Diamond Industrial and GDM Technologies into one company. With this merger, we have combined the strengths and legacies of each company to continue providing unparalleled quality and service.

Joseph & Amanda Otterstrom with their children.

Joseph has been with Terra Diamond since 2015 and has over 19 years’ experience in manufacturing. He will continue the tradition of leadership to get the product to our customers the way they need it, on time, with an uncompromised level of service.

Our Story

Terra Diamond and GDM were each founded to create the products cutting and coring companies needed. As the years have passed, innovation and quality craftsmanship shine through, keeping both Terra Diamond and GDM at the forefront of the competition.


Al Shuman with his first saw.

In 1963, Al Schuman started GDM Equipment after designing the first track-mounted wall saw. Using straight-forward design and quality materials, GDM became known for reliable, user-friendly equipment without compromise.

Pat O’Day testing saw blades - 1975Pat O’Day testing saw blades – 1975

Terra Diamond began in 1978 with Pat O’Day, who set out to build a company that specializes in the manufacturing of diamond blades, bits, and grinding products of the highest quality. This legacy of quality continues today.

For over half a century, we have built high-quality diamond tools and equipment that we are proud to say are MADE IN THE USA.

With decades of manufacturing experience, we build the tools needed to get the job done, so our customers can depend on us to build what they need, when they need it.

We remain dedicated to producing high-quality tools and equipment. We innovate, improve, and streamline our products to meet customer needs.

WHEN YOU NEED US, WE’LL BE THERE.