Valued Business Partners:

We are excited to announce effective December 30, 2020, SEI Technologies has acquired Williamson Machine Co., Inc. This merger will bring additional markets, customers, and capacity to our portfolio as we look to strengthen our position during this global pandemic.

Williamson Machine, located in Hickory, NC, was incorporated in 1981. Don Williamson and his team provide manufacturing and services to a wide range of customers including wire and cable manufacturing, automotive tooling, rubber and thermoplastic hose manufacturing and many more. Williamson provides a similar range of capabilities to SEI including CNC Milling and Turning, Wire EDM, small hole EDM, Surface Grinding, Heat Treating, Tig/Mig Welding, and other support operations.

As a result of the merger, Williamson Machine will begin operating under the name SEI Technologies as our dba (doing business as). We will be reaching out to all current customers for introductions and to provide new contact information and discuss confidentiality agreements, support, etc. Don and his staff have agreed to remain and provide support through the transition as we integrate the business in Q1 of 2021.

SEI Technologies currently operates out of locations in Hickory, NC and Harrisburg, NC, as well as a support office in Gold Canyon, AZ.

The SEI Hickory location is AS9100 rev D certified and performs new part manufacturing, overhaul, and repair services for a variety of markets including racing, automotive, aerospace and defense, the US military, and our allies around the world. Capabilities include 5-axis CNC machining, EDM, grinding, TIG welding, vacuum brazing, heat treatment, abrasive blasting, glass bead, fluorescent penetrate inspection and more.

The SEI Harrisburg location is a precision machining and tool & die operation, specializing in extrusion dies, stamping dies, specialty tooling with quick turn-around of all machining services including complex parts and reverse engineering services. Precision machining capabilities include wire, sink, and fasthole EDM, CNC milling, drilling, turning, ID-OD grinding, surface grinding, heat treating and more.

We appreciate your support during our many years of service and look forward to offering a broader range of services to our customers. Should you have any questions or wish to update your records please contact Angel Johnson at or 828-855-1652 and we will be happy to help.


Rick M. Harris
SEI Technologies