We sell numerous sizes of large diameter rods that are machined out into tube. This process is not just time consuming but also expensive. Some customers have to machine out more than 50% of the plastic they paid for in every operation. If you are strictly limited by your application as to the material you can use, then you may not have any other options. But if the application allows for material flexibility there are two great ways to make this process more cost effective.
The simple answer is to buy a tube in a wall thickness you can machine to size. One huge advantage of buying tube is the annealing process offers a better stock shape to machine from. Tube is essentially annealed on both the OD and ID. Another is the obvious savings in scrap and machine time. Tube can be hard to find. Let me first clarify that I am distinguishing tube from pipe. A pipe material that is meant to handle fluids is readily available in many standard products for the job. Tube is usually a stock shape to machine some hand of widget to complex geometry for a special purpose or made to print item. The reason tube stock shapes can be hard to find is because of the limits of manufacturing technology, volume and variety of sizes.
For low to medium volume machining where the aforementioned material flexibility exists, consider using some basic materials like cast nylon or acetal tube. Both materials can work in a wide variety of applications and offer cost savings in machine and material scrap rates. Plastics International stocks a wide variety of both materials and can cut and ship a length out same day if you can use one of our many stock sizes. We can also custom order special wall thicknesses and outside diameters to fit you specific needs. Keep this in mind the next time you are machine a rod or disc, ask if tube is available in a material you can use for your application.