Why Large Machining is Different

One of the most common stories we hear at Bronte is from customers who have sent out large machining to a jobbing machine shop who have struggled with the parts. What makes large machining so different and what factors come into consideration?

Set Up

Before we talk about the actual machining, it’s important to bear in mind the impact that large sized components have on setup. Most often a combination of forks, cranes and hoists are required and this has an impact on health and safety, and time spent loading the machines.

Not Just Capacity

One of the most obvious factors when it comes to machining anything large in size is having the right machines to actually perform the work. Not only do the machines need to be able to accommodate large and potentially heavy components, but they must remain highly rigid when doing so. Having the machine and being able to run large parts are of course different skills. Large part machining required skilled staff and is not as transferrable as you might expect. The various factors which affect machining accuracy are magnified to such a point they have to be taken more seriously than at conventional sizes.


Two of the key factors that influence the machining performance are temperature and stress. With larger sized components, thermal stress can play a much bigger part in the machining and keeping parts at room temperature is important. Another important factor is material stress. As you remove material, the part may deform due to the residual stresses found in welding or casting. When roughing out the workpiece there is a delicate balance between remaining light enough to leave enough material for finishing, yet deep enough to unlock the stress related distortions.

Where you have large sized and irregular components, castings or fabrications which require CNC machining, why not try Bronte Precision. Over the last 5 years we have gone from being a jobbing machine shop to focusing on this niche and have the machines/staff and layout to accommodate this work. Send through your RFQ for a no obligation quotation to Oliver: