Material and stock size
Material grade, stock form, minimum purchase quantity and waste affect raw-material cost. Difficult-to-machine alloys can also reduce cutting speed and tool life.
Geometry and setups
Features that require multiple orientations, deep cavities, long tool reach or special workholding add programming, setup and machining time. Consolidating setups may improve consistency but can require different equipment.
Tolerance and measurement
Tighter requirements should be limited to functional features. They may require slower processes, environmental control, additional inspection and a defined measurement method.
Volume and repeatability
Prototype pricing carries programming and setup cost across fewer pieces. At higher volumes, fixtures, process optimization and material purchasing can change the most economical route.