Materials
Materials Vietnamese 5-Axis Shops Cut, and What Each One Does to Your Quote
Material changes the price of a 5-axis part more through cutting time and shop choice than through the cost of the bar. It also narrows the list of shops that can quote at all. Below is how we read the material line on a drawing.
| Grade | And the standard it is bought to |
|---|---|
| Condition | Temper, annealed, hardened or aged |
| Certificate | EN 10204 2.2, 3.1 or 3.2 |
| Supply | Shop buys, or you free-issue |
| Substitution | Allowed with approval, or not at all |
Metals, their designations and the shop pool
Designations are close equivalents for reading a quote, not a statement that two standards are identical. "Pool" is our plain reading of how many shops in Vietnam run the material regularly on 5-axis simultaneous or 3+2 indexed work.
| Grade | Designations | On a 5-axis machine | Pool |
|---|---|---|---|
| Aluminium 6061-T6 | UNS A96061 · EN AW-6061 · JIS A6061 | Fast, forgiving, good surface straight off the tool. The usual first material for housings and manifolds. | Wide |
| Aluminium 7075-T6 / T651 | UNS A97075 · EN AW-7075 · JIS A7075 | Stronger, holds thin ribs better than 6061. Thick plate is often imported to order. | Wide |
| Stainless 304 | UNS S30400 · EN 1.4301 · JIS SUS304 | Work hardens. Rigid setup and steady feed matter more than on aluminium. | Wide |
| Stainless 316L | UNS S31603 · EN 1.4404 · JIS SUS316L | Gummy, slower than 304. Specify it exactly; it is the grade most often swapped for 304. | Moderate |
| Stainless 17-4PH | UNS S17400 · EN 1.4542 · JIS SUS630 | Cut in solution condition, then aged. Ageing moves dimensions slightly, so finish allowance is planned. | Moderate |
| Tool steel (H13, D2, P20 type) | H13: EN 1.2344 · JIS SKD61. D2: EN 1.2379 · JIS SKD11 (close) | Mould and die inserts. Hardened work needs hard milling or EDM and a narrower pool of shops. | Moderate to narrow |
| Titanium Grade 5 | UNS R56400 · Ti-6Al-4V · EN 3.7165 | Low thermal conductivity pushes heat into the tool. Lower cutting speeds, fresh tools, high pressure coolant. | Narrow |
| Nickel alloy 718 | UNS N07718 · EN 2.4668 · JIS NCF718 | Work hardens fast, tool wear is high, cycle times are long. Few shops quote it routinely. | Narrow |
| Brass C36000 | UNS C36000 · EN CW603N · JIS C3604 (close) | Free cutting, short chips, good finish. Mostly turned or mill-turn parts. | Wide |
| Copper C11000 / C10200 | UNS C11000 · EN CW004A · JIS C1100; oxygen free C10200 · EN CW008A · JIS C1020 | Soft, burrs easily, smears on dull tools. Thermal and electrical parts. | Moderate |
UNS numbers follow the Unified Numbering System. For a binding comparison, check the chemistry and mechanical limits in the exact standards on your drawing.
What 5-axis changes about the material question
On a 3-axis job the material mostly decides cutting speed. On 5-axis it also decides how far the tool can reach. A tilted tool on a deep feature works at a long stick-out, and a long tool in stainless or titanium chatters where the same tool in aluminium would be fine. That is why a part that quotes well in 6061 can fail to find a shop in 316L.
Machining in one clamping also means stresses come out of the material in that same clamping. Aluminium plate and forged blanks move when a large share of the volume is removed. Shops handle this by roughing, releasing and re-clamping, then finishing, which costs a little time and saves the tolerance. Ask how the shop sequences a part that removes most of its block.
For 5-axis simultaneous surfaces such as blades and blends, the material sets the finish you get from the tool: a smooth surface in aluminium, visible scallops in titanium unless the step-over is reduced. For 3+2 indexed work on prismatic parts the difference between materials is mostly time.
Common grades such as 6061, 304 and POM are usually on the shelf at Vietnamese distributors. Thick 7075 plate, 316L in large bar, titanium, nickel alloys and filled PEEK are often imported to order, which adds weeks before cutting starts. If a close equivalent grade is acceptable, say so on the RFQ.
Write the material line so three shops quote the same thing
Every item is something a shop can price. Leaving one out is the most common reason quotes cannot be compared.
- Grade and standard. "6061-T6 to ASTM B221", not "aluminium". "SUS316L to JIS G4303", not "stainless".
- Condition on delivery. For 17-4PH say H900, H1025 or H1150. For tool steel, the hardness range after heat treatment and who does it.
- Certificate type. EN 10204 3.1 traceable by heat number is a sound default for industrial parts.
- Blank form. Plate, bar, forging or near-net casting. A forging changes the toolpath and the price.
- Substitution rule. "No substitution" or "equivalent grade with written approval".
- Finish that depends on material. Hard anodising wants 6061 or 7075, passivation applies to stainless. Name the specification.
Engineering plastics on 5-axis
Plastics are mostly 3+2 indexed work: housings, manifolds and fixtures with features on several faces. Around ±0.05 mm is a realistic general target, tighter on selected features in stable plastics.
PEEK
High temperature and chemical resistance. Ask for annealed stock and confirm unfilled, glass or carbon filled. Expensive, so scrap matters.
POM (acetal)
Stable and easy to machine. Copolymer for dimensional stability, homopolymer for stiffness.
PEI (Ultem)
Stiff, flame resistant, used in electronics and test fixtures. Brittle on sharp internal corners.
PA6 / PA66
Absorbs moisture and changes size after machining. Measure conditioned parts or allow for it in the tolerance.
PTFE
Soft and creeps under clamping. Thin sections and tight tolerances do not mix.
PMMA and PC
Clear parts. Say whether machined faces must be polished transparent.
Related pages
- Processes. Machine layouts, toolpaths and the operations around the 5-axis machine.
- Parts. Part families, and which need 5-axis simultaneous or 3+2 indexed.
- Parts and materials guides. Longer guides by material and part type.
- Send an RFQ. Material, quantity and tightest tolerance are enough to start.
Questions about materials
Which material is cheapest to 5-axis machine in Vietnam?
Aluminium 6061, by a margin. It cuts several times faster than stainless or titanium, the stock is easy to find, and the widest pool of shops runs it every week. If the part allows 6061, the quote and the lead time both benefit.
Can a Vietnamese shop machine titanium or Inconel on 5-axis?
Some can, and the pool is small. We ask for the material they cut last month, not whether they are willing to try it. If your part sits in titanium or nickel alloy and the fit is weak, we say so instead of sending it to shops that are learning on your job.
Who buys the material, the shop or me?
Usually the shop, against the grade and certificate on your RFQ. Some buyers supply bar or forgings themselves for traceability or cost. Either works, as long as the RFQ says which, so the shops quote the same thing.
What certificate should I ask for?
An EN 10204 type 3.1 inspection certificate traceable by heat number to your parts covers most industrial work. Put the certificate type on the RFQ; asking for it after the material is bought rarely works.
Send the drawing with the material line
We check whether the grade, condition and certificate can be sourced in Vietnam, and match the part to up to3 shops that cut that material today. We reply within 24 business hours.