Gear Cases

Our Gearbox Cases start out as 60kg blocks of billet 7075-T6 aluminum alloy.


Whilst it’s an expensive material, this is one of the strongest aluminum alloys available and is the industry standard for many aerospace and military applications. 7075-T6 alloy is as strong as many steels with tensile strength of 78,000 PSI.

The strength and rigidity of a gearbox casing is crucial for gear performance, so we elected not to compromise performance by choosing a less costly material. We wanted the maximum strength and precision possible in our gearbox casings and the best way to do that is to program CNC four and five axis milling machines to carve the exact shape that we need out of the billet.

Not only does this provide the maximum strength and rigidity possible, but the robotic repeatability in the machining process allows us to reduce some of our tolerances down to just 5 microns.

The CNC mill creates a finish that you simply cant get by casting…there’s no rough sand cast marks, no ridges and valleys, no pin holes, just mirror smooth presentation. Once the perfect case comes off the mill, our HGT Precision brand is proudly etched into the casing and then polished to close the pores and slow down the oxidation process keeping the “shiny as new” look for years to come.