Holman played a part in World War II making the Polish designed 20mm Polsten gun, similar to the Oerlikon but simpler to build and use.

In 1910, the company took first and third prizes in a World Rock Drilling Contest, sponsored by the South African Chamber of Commerce.

Like the Rover jet car of the same era, the excessive fuel consumption made the project non-viable.

1954 or thereabouts Holman Bros took over the Climax Rock Drill and Engineering Works formerly Stephens Iron foundry.

1959-Holman introduced the Rotair, Britain's first single stage oil flooded rotary screw compressor.

1961 Trade names included Holbit rock drill steels, Dustuctor – a dust containment system, Goodyear Pumps which used an Archemedies screw principle with a meshing disc which was capable of pumping strawberry jam without crushing the strawberries, Tractair – a compressor mounted on the PTO of a tractor, Rotair, Maxam – Maxam Power ltd who produced pneumatic control components.

By May 2003 "Portable Compressor manufacturer CompAir, which employs 184 people in West Cornwall, announced earlier this month that increasing international competition meant it was intending to close its Camborne operation by September.

The manufacturing operation was transferred to the Simmern works in Germany formerly owned by Mannesman Demag before its purchase by CompAir.

The CompAir Group has now (2012) been bought by Gardner Denver along with a number of other British compressor related companies.