Work to drawing or sample starts with a manufacturability review: we check draft angles, wall thickness consistency, machining allowance and the locations that will need a core. Those comments go back before the pattern is made — after casting they can no longer be corrected, and reworking the pattern is paid for twice. Material is chosen for the service: СЧ20, ВЧ50, steel 20 or 09Г2С.
The first casting is presented as a sample: measurements to drawing, a dimensional report and, where required, chemical analysis and hardness. The batch is released only after written approval — cheaper than finding the deviation on finished parts. The pattern is made for that specific item and stored at the factory; ownership and storage terms are written into the contract.