Vulcan On-Board Scales are manufactured by Stress-Tek, Inc, which was founded in 1978 in Kent, Washington, near Seattle. Stress-Tek, Inc. originally provided professional consulting services in the fields of transducer design and experimental stress analysis.

Our operations have since expanded to the design and manufacturing of state-of-the-art force measurement devices for the Vulcan On-Board Scales business. Today we provide products to the trucking markets including timber, refuse, aggregate, and general trucking, as well as solutions for the aerospace, marine, medical, heavy machinery and process controls markets.


Our modern facility provides more than 45,000 square feet for our operations, including a 9,000 square foot machine shop. Our in-house machine shop has a full compliment of computer numerical control (CNC) machine tools. This capability allows us vertical integration from concept to product support.

Our quality control program incorporates standards to satisfy exacting customer requirements such as those of the aerospace and medical industries. Each load cell is tested and calibrated individually using certified test equipment, allowing load cells to be interchanged without requiring recalibration.


Our design team has access to the latest engineering tools and techniques allowing us to understand and address customer requirements. We have over 300 load designs and more than fifteen patents, with additional patents pending.

Vulcan On-Board Scales are supported by the best sales and service team in the industry. Our goal is 100% customer satisfaction. Our products are sold by knowledgeable dealers throughout the United States, Canada, and worldwide.