[2] The west coast beaches of the North Island of New Zealand between Kaipara Harbour and Whanganui contain ironsand deposits rich in the mineral titanomagnetite.

A prize offered by the Taranaki Provincial Government was never claimed, mostly due to problems encountered by people attempting to process the iron sand, such as a viscous slag of titanium carbides and nitrides that forms and blocks equipment when heat is applied to the sand.

[6] Glenbrook was chosen as the site due to the area's proximity to the Waikato North Head ironsand mine and Huntly Power Station.

[4] Commercial operations began in 1968, with imported feed coil being used to produce steel for domestic and Pacific Island markets.

The steel company ran at a loss during the 1970s, until 1981 when a more optimised, commercially viable method for extracting iron was implemented, leading to an expansion of the Glenbrook facilities.

In 1992, BHP took up a controlling interest with an 81% shareholding by acquiring the shares of Fisher & Paykel and Steel & Tube.

[6] On 21 May 2023, Prime Minister Chris Hipkins announced that the New Zealand Government would provide funding of up to $140 million for an initiative to halve the consumption of coal at the Glenbrook plant and reduce carbon emissions.

The project involves installation of an electric arc furnace to replace coal as the heat source for recycling scrap metal.