The Challenge Steel windmill was first made in 1906 and was for several years the "top-of-the-line" windmill manufactured by the Challenge Company of Batavia, Illinois, USA. It disappeared from the company's product line around 1918 but some farm implement directories listed it into the mid 1920's. The Challenge Steel was available in 6, 8, 10 12, 14 & 16ft diameter windwheel sizes.
The Challenge Steel was an open internal-geared steel windmill, sometimes also referred to as a planetary-geared windmill. The windwheel had sections of curved galvanised steel blades attached by riveted steel brackets to steel rims, which were in turn bolted to steel arms. The arms were then bolted to the cast hub and wheel brace spider at the front end of the main shaft. The vane was made of the same galvanised steel sheet material as the blades and was strengthened by a heavy wire reinforcement around its edge.
An identifying feature of the Challenge Steel was the side vane which assisted with the governing of the mill, and the internal gearing.
The Challenge Steel, like the Dandy, could be supplied with either graphite bearings or babbitt bearings. The bearings were reversable and interchangeable, so that when the lower halves of the bearings became worn, they could be interchanged with the upper halves to extend their life.
The Morawa Museum example is displayed on a short tower in the Museum yard. The agent in WA was George Wills & Co. in Perth.