It might be a hard pill to swallow, but many CNC machine shops can produce better quality components at a lower price than a typical in-house operations. Injection mold making, tool-and-die and aerospace companies can benefit greatly from the capabilities of a high quality CNC machining operation.
Instead of going through the expense and time to develop your own CNC milling, EDM, WEDM, grinding or drilling department, it is often more cost efficient to request the services of a machine shop. These shops are set up to produce parts in mass quantities or some specialize in one-off manufacturing. This has become an integral part of the mold making process.
Once established with a machine shop it will be easy to have a good, working relationship. With the immediate needs of industry it is vital to connect with a machine shop that can move parts in a timely fashion.

Expectations are naturally going to be high when it comes to getting the correct part; after all, that is what you are paying them to do. Even the most slight deviation can throw off the production schedule, and short delivery dates are often the deciding factor in winning jobs.
Take a visit to the outsourcing shop
Stories abound of shops with pretty receptionists and foyers, but atrocious machine shops. It is one thing to talk on the phone, check out websites, and read brochures, but quite another to physically visit the potential supplier.
Qualities of a good CNC machine shop
Ability to create precise, high quality parts | Ability to create parts in a timely fashion | Ability to make parts with short notice |
Ability to deliver parts without delays | Ability to create cost efficient parts | Ability to show certification in up-to-date machining |
Outsourcing the outsourcing
Some machine shops will use resources by engaging other machine shops to subcontract a job. Be certain that the same expectations for quality are communicated to both machine shops.The machine shops used for sub-contract work should be willing to accept a visit as well for purposes of verification.
Certifications should be current and proof should be readily available. This is important because the parts that are being produced will need to meet the standards of any company that backs up the end product. If inferior parts are produced then product quality will reflect this.
Certification that is common with quality is ISO 9001:2000. ISO is the International Organization for Standardization. When a company is certified with ISO they are required to comply with certain standards. The code of ethics must be followed.

It is also quite common in China for your outsourced mold to be outsourced to numerous sub-contractors. You may, in fact, never really know just who made what and it is somewhat out of your control. In this case, make sure your primary source is responsible for the results!
It is advisable to follow the Soviet cold war policy of “trust and verify” when dealing with any type of outsourcing. More than one company has been burned by fake components that had all the correct etchings and labels, but were really just cheap knock-off imitations of the real thing.