A deep hole is normally considered to be one where its depth is 10x greater than its diameter. Shorter holes can normally be achieved with a regular drill bit, but this is not suitable for longer holes due to the unavailability of tooling, and retaining concentricity and accuracy of the hole.
The fundamental process may also be known as gun drilling, drilling or boring, with the subtle differences relating to the specific design of the tooling. Coolant is delivered to the end of the tool to prevent the tool from overheating, but also to remove the swarf. As the length of the hole can extend to several metres, removing swarf all the way back to the beginning of the hole is a key challenge.
Langley Alloys operates its own deep hole borer, capable of creating a hole up to 8” (200mm) in a solid bar >2m in length. This process can be done in less than one hour, including high-strength alloys such as super duplex stainless steels and nickel alloys, saving considerable time for customers. By undertaking first stage machining, Langley Alloys can reduce the overall lead time compared with using subcontractors, as well as reducing cost by removing the additional transportation costs between locations.