In round figures, GM-H used 300 Australian suppliers of components, materials, parts and services in 1948 on the first model Holden. 10 years and half a million Holdens later, this number had grown to over 4,000 such was the demand for Australia’s Own! By the end of the 1970s, the number of outside suppliers reached an amazing 5,000 at its peak during the time the HZ model series was in production.

These outside suppliers were located all across Australia and not just in areas close to GM-H plants. Raw materials like iron, metallurgical coke and steel comprise some of the less obvious. Items such as paint, interior trim materials, glass, body hardware and fasteners, and electrical components are to name just a few readily visible examples of what was purchased by GM-H for Holden manufacture and production.

Outside supply was the subject of a tendering process, and as such the situation arose where minor detail differences over time and location in the production of a Holden were to become a way of life. Working from both engineering and material specifications, these outside suppliers would manufacture the required components and parts as used on the various Holden models through the decades.

The production of any given Holden model was never a case of every car having every single component identical in every way. For one thing, Holdens were supplied with varying makes of tyres fitted to them – the one common denominator in this instance being the size and performance specification of the tyre.

Parts and component assemblies of engines, transmissions, rear axles, steering systems and so on were all part of a huge operation in having the end products come together as and when required in a gigantic “as forecast” production system.

Other visible items included, but were not limited to, body fasteners, generators (and alternators), brake components, windscreen wiper motors, seat belt assemblies, wheels, hoses, fluid couplings, and so on. It is easy to see how the number of outside suppliers grew to 5,000 by the time the HZ was in production.