In 1660, English scientist Robert Hooke created Hooke's Law. Hooke realized that object deformation, even small deformations or directly proportional to the force or load causing the deformation. In other words, the deformation of steel is linear.
Because the deformation of steel is linear, and because steel has a memory, the physical characteristics of steel were perfect to be the basis of a beam wrench.
Walter P. Chrysler was watching his assembly line workers torque heads on to the aluminum blocks. It was 1924.
To fully understand the genius of Walter P. Chrysler, consider the facts. In 1924, aluminum was still relatively new. It wasn't really fully extracted and processed until 1886. Aluminum engine blocks are common today. But back in 1924, aluminum was cutting edge technology and was used for racing engines.
The problem was that the engines were blowing up. Despite being a phenomenal engineer, Chrysler couldn't diagnose the root cause until he watched two workers tightening the head bolts. One worker was big, strapping fellow while the other one was small in stature. Each worker did their best to tighten the bolts to their definition of tight. Their size and ability to use leverage made their definitions dramatically different. Chrysler remembered Hooke's Law, and used it to develop a wrench that would measure how tight a bolt was being torqued. It was the flat beam torque wrench.
That was the start of the torque tool and error proofing industry. Chrysler wanted to build cars, not tools. He licensed Paul Sturtevant to manufacture and sell the torque wrench. The rest, as they say, is history.