Donut

FUTEK Donut load cells, also known as through-hole or washer load cells, are annular force sensors with a central bore through which a fastener, shaft, rod, or cable can pass. This unique geometry allows force measurement to occur directly in line with the mechanical assembly without requiring the force path to be redirected or interrupted. The sensor sits between mating surfaces and measures the compressive force transmitted through the bolt or clamping element, making it the preferred solution for bolt-load monitoring, fastener preload verification, clamp force measurement, and in-situ force sensing in existing mechanical joints.

FUTEK’s Donut load cells use a precision-machined ring element with bonded foil strain gauges and a Wheatstone bridge circuit. The annular geometry distributes load uniformly around the measurement element, providing excellent repeatability and minimal sensitivity to load point variation as long as the load is applied concentrically. Low-profile designs minimize the added stack height in the mechanical assembly, and stainless steel versions with sealing offer protection in harsh environments.

Capacities range from small clamping forces up to very high preload values for structural bolt monitoring in industrial and infrastructure applications. Sensors are available in multiple bore sizes to accommodate standard fastener sizes from small machine screws through large structural bolts. Electrical output in standard mV/V is compatible with any strain-gauge data acquisition system; integrated amplifier options provide direct analog or digital output.

NewRoad provides FUTEK Donut load cells in Israel for bolt-load monitoring in structural, mechanical, and manufacturing applications, fastener certification testing, press force monitoring, and any application where force must be measured in-line with an existing mechanical element.