A gripping story

Adjustable Spanner

One day in the late 1880s, Johan Petter Johansson could not find a single pipe wrench in his engineering workshop in Enköping. His employees were all working on remote jobs and had taken the workshop’s entire set of fixed pipe wrenches along with them. That quandary would eventually lead to one of the world’s most practical inventions: the adjustable spanner (wrench).

Johansson solved the problem of his missing pipe wrenches by fabricating a wrench with jaws that could be adjusted to fit the dimensions of a pipe. In 1888 he obtained a patent on his invention, called the plumber’s wrench. It quickly became a commercial success. He then turned his attention to fixed spanners for nuts and bolts.

For centuries, blacksmiths had forged long-handled tools for gripping and turning various types of threaded metal parts. One early use was for assembling knights’ suits of armour, but perhaps their most important purpose was to tighten wagon wheels to prevent them from coming loose. Initially, nuts and spanners were made individually, but production started to become fairly standardised in the 19th century. People could purchase sets of spanners in common sizes.

Inventors also started experimenting with various types of adjustable spanners. In 1842, an English engineer named Richard Clyburn created a version with two moveable jaws that could be adjusted by means of a screw. It is unclear whether Johansson knew about Clyburn’s invention. In any case, Johansson obtained a Swedish patent his original design by making one of the jaws fixed and one moveable by means of a screw device. In 1892 he obtained a patent on this adjustable spanner, which is essentially the same model still in use all over the world. In Denmark, it is commonly called a svensknøgle (meaning ‘Swedish key’), while the Russian and Hebrew nicknames for the tool translate as ‘little Swede’.

One of the very first adjustable spanners made by J.P. Johansson, patented in 1892.

Today Bahco, the company founded by Johan Petter Johansson, has sold more than 100 million adjustable spanners. Johansson handed the business over to his sons in 1916 so he could devote more time to his inventions. He obtained more than 110 patents, but the adjustable spanner was his most significant innovation.

Johansson also has fans who celebrate him for his sugar tongs. They came about after his wife complained when he came in straight from the workshop and used his dirty fingers to pick up a sugar lump from the bowl for his coffee. Even if the sugar tongs did not have the same impact as the adjustable plumber’s wrench and the adjustable spanner, it is yet another example of a Swedish inventor’s ability to draw inspiration from the practical problems of everyday life rather than dream of revolutionary creations.

Aviation pioneer Katherine Sai-Fun

Choung uses an adjustable spanner to tighten a nut in Los Angeles in 1933.