Alloy Sizes

The simplest example of an optimised size selection is the choice of a round bar that is closer in cross-sectional diameter to the final component (see diagram below). Two through-cost savings are made: there is less machining required on the bar so machining through-costs (operator time and tool wear etc.) is lower, and the scrap though-costs are lower because less scrap is produced.

Machining Cost Savings

The closer the raw material is in diameter to the finished component, the greater the cost=saving and it may even by possible to purchase a bar that is exactly the size required for the finished component. Bars can be produced to very close tolerances in the first place, and if this is possible the total cost of the machining operation will be saved. If you’re using large amounts of the raw material it may even make economic sense to have a very specific diameter and/or tolerance produced at the production mill. A second example of optimised size selection is the choice of bar length. Bars will often be supplied in full, standard, lengths, but this may not be ideal for your application (see diagram right). By choosing a bar length that is an exact multiple of the length of your finished component, it may be possible to make a significant through-cost saving on scrap.

Optimum Shape Selection

It may seem very obvious, but many people overlook the possibility of buying raw materials in shapes that more closely match their requirements. Round bar is very popular and indeed sometimes cheaper to purchase but machining it down to other shapes (e.g. hexagons) is often a false economy. One example that is often overlooked is the use of hollows. Rather than purchasing a round bar only to machine away its centre, a hollow can be purchased in the first place and the machining and scrap through-costs eliminated.

Optimum Grade Selection

Optimising the grade (alloy) of material you purchase is perhaps more difficult than optimising the size and/or shape, but it can have a major impact on through-costs. Production costs can be increased dramatically if an incorrect grade of materials is selected. For example, if a particular grade that is selected is difficult to machine, the machining times and associated costs will be higher. However, that particular grade may have been chosen because it was necessary to achieve the required finished component performance. In optimising grade selection, a balance must be struck. Component performance criteria must be matched against the possible through-cost savings that can be made by improving the efficiency of manufacturing processes.

For more information about through-cost savings, please take a look at our bespoke supply solutions.