The decision as to what process to use for producing cut parts is not always straightforward and can vary depending on material, quantity required and flexibility of supply.
Routing or milling is generally used for thicker more rigid materials as these are harder to cut using other methods. Sheet materials such as SRBP, SRBF and GRP are all usually routed or milled. However, it is important to remember that internal corners will always have a slight radius due to the nature of the process.
It is possible to stamp these materials out as well, although they require quite expensive tooling in order to do so and therefore it only becomes cost effective when large quantities are involved.
Stamping is generally the cheapest way of producing large quantities of a part, however because of the cost of tooling, it is not effective for smaller quantities and is also inflexible if changes are required. When this happens, a new tool is usually required and therefore adds to overall cost. Stamping also has dimensional limitations as tools and machine heads have size restraints.
Cutting, using flatbed two axis cutting machines, is both cost effective and flexible for the customer. Both small and large quantities can be produced effectively and there are no tooling costs, so changes can be quickly implemented. Almost any size item can be produced with very good accuracy. Various cutting heads can be used from simple blades to laser or sonic cutters depending on the material being processed.
To summarise, routing is generally the best for rigid materials, stamping for small parts in large volumes and cutting for everything in between.