Functionality CNC Alloy Machining Services

• 1
  What matters before you send an RFQ
• 2
  Which supplier format fits your part
• 3
  How alloy choice changes the machining plan
• 4
  Tolerance, finish, and part size limits
• 5
  Lead time, MOQ, and what drives both
• 6
  Certifications and inspection you should request
• 7
  Pitfalls that show up after the PO
• 8
  How to prepare a functionality CNC alloy machining RFQ

Alloy is the first variable we look at when a drawing arrives. Aluminum 6061-T6 and 6082 machine fast and hold tight tolerances with little fuss. 7075 is stronger but more prone to chipping at the edge, so we slow the feed and take lighter passes. Magnesium AZ31B and AZ91D cut even faster, but the chips are a fire risk and need dedicated handling.

Stainless and steel behave differently again. 303 machines cleanly, while 304 and 316 work-harden if the tool rubs instead of cuts. That is why we set a minimum chip load rather than letting the tool dwell. 17-4PH in the H900 condition is hard on inserts, so we plan for more frequent tool changes and a rougher-then-finish sequence.

Titanium and nickel alloys are the slow end of the range. Ti-6Al-4V and Inconel generate heat at the cutting edge, so coolant delivery and toolpath strategy matter more than spindle speed. A part that takes 40 minutes in 6061 might take several hours in Inconel. That difference should appear in the quote, not as a surprise later.

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  Aluminum6061-T6, 2024, 5052, 5083, 6063, 6082, 7075, ADC12.
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  Stainless303, 304, 316, 316L, 420, 430, 431, 440C, 17-4PH.
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  Steel1018, 1045, 4130, 4140, 4340, A36, tool steel.
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  Titanium and special alloysTA1, TA2, TC4 (Ti-6Al-4V), Inconel, magnesium AZ31B / AZ91D.

A tolerance callout is only useful when it matches the feature. We hold ±0.005 mm (±0.0002 in) on critical diameters, bores, and mating faces. General walls, pockets, and non-mating surfaces do not need that number, and forcing it everywhere raises cost without improving the part. Mark the tight features on the drawing and leave the rest at a sensible block tolerance.

Surface finish follows the same logic. Ra 1.6–3.2 μm is a normal as-machined surface. Ra 0.8–1.6 μm is a fine finish that usually needs a separate finishing pass or a smaller step-over. Ra 0.2–0.8 μm is reserved for sealing faces and sliding surfaces, and it is worth specifying only where a seal or bearing actually runs.

Part size decides which machine the job lands on. Our largest travel is 4,000 × 400 × 150 mm, which suits long frames and rails. Medium work runs on 750 × 1,150 × 550 mm and 600 × 600 × 600 mm machines. Compact parts, including medical and electronic housings, run on 500 × 500 × 450 mm and 500 × 310 × 200 mm machines. A Ø400 mm rotary table handles round and indexable work.

The practical question is whether the part fits in one setup. Every extra setup adds a datum shift. If a feature can be reached with a 5-axis move instead of a second op, the tolerance stack gets shorter and the schedule gets tighter.

We quote and return DFM analysis within 12 hours. Production can start within 24 hours of a released order, and parts typically ship in 3–5 days. Those numbers assume the drawing is released, the material is in stock, and no finishing step is holding the batch. Historical late-delivery probability is below 2%.

There is no minimum order quantity. One prototype and a 10,000+ part run go through the same quoting process. The difference is in the process plan: a prototype may be machined from billet, while a production run may move to die casting with CNC finishing if the geometry and volume justify it.

Material availability is the most common lead-time variable. 6061-T6 and 303 stainless are usually on the floor. Inconel, Ti-6Al-4V, and beryllium copper often need to be ordered, which adds days before the first chip. If your schedule is tight, tell us the alloy early so we can confirm stock before the PO is cut.

Finishing adds a second schedule. Anodizing, electroless nickel, and powder coating run in batches. A small batch can wait for a tank load. If the finish is cosmetic, send a sample or a color target with the RFQ.

Certification requirements depend on where the part ends up. General industrial work needs ISO 9001:2015. Automotive and EV programs usually require IATF 16949:2016. Medical device components fall under ISO 13485:2016. If your drawings and models are sensitive, ISO 27001:2022 covers information security.

Inspection is the part buyers forget to specify. We inspect 100% of parts before shipment, with a raw material check, in-process monitoring, and a final inspection. Inspection reports are available on request. If a feature is critical, say so on the drawing and we will record the actual measurement rather than a pass or fail.

First article inspection is worth asking for on any new alloy or new geometry. It catches tool wear, fixture deflection, and datum errors before the run is complete. On tight-tolerance work, in-process probing keeps the machine honest between tool changes.

For regulated programs, ask what the supplier will hand over: material certs, inspection reports, and a process flow. A shop that cannot produce those documents quickly is a schedule risk, not just a paperwork risk.

The most expensive mistake is a quote that ignores the process plan. If a supplier prices a 5-axis part as a 3-axis job, the first article will miss. Ask what machine the part will run on and how many setups are planned.

The second is a tolerance callout that nobody checked against capability. A ±0.005 mm bore in a deep pocket is a different problem from the same tolerance on a short diameter. Suppliers should tell you when a callout is unrealistic instead of accepting it and missing later.

The third is finishing quoted outside the shop. When anodizing or plating is subcontracted, the schedule depends on a third party. Ask whether finishing is in-house and how it affects the ship date.

The fourth is missing documentation. Regulated industries need material certs, inspection records, and traceability. Confirm what is included before the order starts, not after the parts are boxed.