Discusses the selection of Armstrongs and Vickers for this study, and the availability of rich archival sources. Provides an overview of the relationship between the British state and armament firms over 1855 to 1955. Records a gradual shift from the government and firms being independent of each other to becoming interdependent. Discusses Katherine Epstein’s assertion in Torpedo that there has been a British Military Industrial Complex since the 19th Century. Considers works from David Edgerton and Edward Packard making a similar case for the inter-war period. Considers the contemporary critiques of the armaments trade, which focused on the independence of armament firm “merchants of death,” rather than identifying collusive relationships with the British state. The chapter then lays out a framework for assessing the independence and power of Armstrongs and Vickers in their relationship with the British Government. Establishes six propositions about the firms’ power and independence that are tested through the book.

Hardness test procedures of various types have been in use for many decades. They are usually quick and easy to carry out, the equipment required is relatively simple and cheap, and there are portable machines that allow in situ measurements to be made on components in service. The volume being tested is relatively small, so it’s possible to map the hardness number across surfaces, exploring local variations, and to obtain values from thin surface layers and coatings. The main problem with hardness is that it’s not a well-defined property. The value obtained during testing of a given sample is different for different types of test, and also for the same test with different conditions. Identical hardness numbers can be obtained from materials exhibiting a wide range of yielding and work hardening characteristics. The reasons for this are well established. There have been many attempts to extract meaningful plasticity parameters, particularly the yield stress, from hardness numbers, but these are mostly based on neglect of work hardening. In practice, materials that exhibit no work hardening at all are rare and indeed quantification of the work hardening behavior of a metal is a central objective of plasticity testing. The status of hardness testing is thus one of being a technique that is convenient and widely used, but the results obtained from it should be regarded as no better than semi-quantitative. There are procedures and protocols in which they are accorded a higher significance than this, but this is an unsound approach.