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Nylon CNC Machining Services for Made-to-Print Industrial Parts
Nylon CNC machining goes wrong on dimensions far more often than on cutting. Published guidance on unfilled nylon 6 and nylon 6/6 puts equilibrium moisture at 1.5–2% by weight in ordinary 35–65% RH air, with a corresponding growth of 0.5–0.6%1 — so a part that measures perfectly in the fixture can land at your dock out of tolerance without a single machining error.
We machine to print at our Jiashan plant. Our documented production record is metal, not nylon, and this page states which parts of that record carry across and which have to be established for your order — before you send files, not after a first article fails.
TOLERANCE CTR
MOISTURE ±1.5%
On this page
At a glance — the six answers a buyer needs before sending files
Spec 01
Quoted per drawing
Industry-typical for custom work: price follows material, geometry, quantity and lead time rather than a fixed price list. Your figure comes back in a written quotation.
Spec 02
3–10 business days, prototypes
Industry-typical machining lead times run 3–10 business days for prototypes, roughly 1–3 weeks for small batches and 3–6+ weeks for production. Stress relief and shipping are additional.
Spec 03
Single parts accepted
Single-part orders are the norm across custom CNC services, and most suppliers set no strict minimum order quantity on machined work.
Spec 04
Tolerance needs a stated condition
A nylon dimension without a measurement temperature, humidity and conditioning state is not an acceptance criterion. ISO 1110 says reproducible values need a specified moisture content.2
Spec 05
Quote in about 24 hours
Industry-typical quoting turnaround runs from instant automated quotes to engineer-reviewed quotes returned within about 24 hours on drawing-led work.
Spec 06
First-article inspection available
First-article inspection reports are a standard option across the industry, scoped per order. Sample charging and credit terms are settled in the enquiry.
Figures described as industry-typical are common practice among custom machining suppliers, shown so you can sanity-check any quotation. They become Zhenling figures only when they appear in a written quotation for your part.
Can We Machine Your Nylon Part?
Yes for turned, milled, bored and ground nylon parts — but the answer that matters is which grade and which measurement state.
Conditioning PA6 to the standard climate of 23 °C and 50% RH is normally taken to put it at roughly 2.5–3% water by weight, and a 2021 study measured 8.83% on injection-moulded specimens held at water-bath saturation.
What transfers to your machined part is the polymer behaviour, not the specimen geometry — and that behaviour governs every tolerance on the drawing.
TOLERANCE.VIEW_ [ACTIVE]
Z-AXIS CALIBRATION … OK
Three Fields Decide Quotability
Route selection follows the drawing, not the material name. A turned bushing, a milled wear plate and a thin-wall housing are three different setups even when all three are cut from the same PA6 rod.
Three fields decide whether a nylon enquiry can be quoted at all: the grade and stock form, the measurement condition, and the surface finish expressed as a value.
Miss any of them and the quote is a guess. A missing material spec adds 1–3 days to a quoting cycle.
Properties Delivered
High Strength Vs Plastic
Carries load commodity plastics cannot (replaces metal in low-load bearings).
- Impact: Excellent under impact, weak on certainty.
- Abrasion: Puts nylon into wear pads. Hardness of the steel counterface matters as much as the grade.
Chemical Environment
Nylon exhibits strong resistance against a specific spectrum of industrial fluids.
- Good against: Hydrocarbons, oils, and standard workshop fluids.
- Poor against: Strong acids and oxidizing agents.
The Water Variable
Mechanical properties move with moisture. The same water that toughens the part moves the dimension.
[DATA] Strength & stiffness FALL
[DATA] Elongation & toughness RISE
[DATA] Elongation & toughness RISE
* The precision you can hold a supplier to depends on which of these properties the part is actually using.
Grade-To-Failure Crosswalk
Nylon is not one material. This crosswalk is organised by what fails, not by what the datasheet advertises. Hover cards to reveal technical matrices.
STOCK.01
Extruded PA6
Lowest stock cost, highest residual stress.
→
Moisture Uptake2.5–3% at 23 °C/50% RH; 8.83% at sat.
Buys YouLowest cost; resin 10–20% below PA66.
Costs YouLargest moisture growth; internal stress.
FamiliesWear pads, guides.
STOCK.02
Cast PA6
Low internal stress, near-net shapes.
→
Moisture UptakeSame polymer as extruded PA6.
Buys YouThick sections without core voids.
Costs YouStill needs stress relief for thin walls.
FamiliesSheaves, large rollers.
STOCK.03
PA66 (Nylon 66)
Higher surface hardness, lower friction.
→
Moisture Uptake2.5% equilibrium, 8.5% saturation.
Buys YouBetter wear against steel counterfaces.
Costs YouHigher resin cost than PA6.
FamiliesWear strips, cams.
STOCK.04
PA6-GF30
Stiffness & reduced stress relaxation.
→
Moisture Uptake~0.1% (0.001 in/in dimension).
Buys YouStructural rigidity under load.
Costs YouAbrasive to tools; rougher finish.
FamiliesStructural brackets.
Datasheet Reversal
Almost every selection guide treats glass filling as a machinability upgrade. Peer-reviewed data runs the other way.
PA66-GF30 produced a best Rz of 2.53 µm against 1.34 µm for unfilled PA66 with an Al₂O₃ wheel.
[TRADE-OFF] PA6-GF30 buys stiffness at a measurable cost in achievable surface finish. Hard fibres abrade the flank face.
The Measured-State Clause
A nylon dimension quoted without its measurement condition is not an acceptance criterion. Both are testing standards, which is exactly why the condition has to be written into the PO.
| ISO/ASTM Standard | Consequence For Drawing |
|---|---|
| ISO 1110:2019 Values obtained at specified moisture |
Name the moisture state next to the dimension, or it is unenforceable. |
| ASTM D618-21 Defines conditioning procedures |
A part conditioned exactly to the standard can still be moving. |
| ASTM Timeframe 20 to 100 days to substantial equilibrium |
Section thickness sets the stabilisation clock, not the calendar. |
Discipline & Warnings
Extruded stock carries locked-in stress. Machined nylon parts are the wrong answer in named conditions.
Three-Cut Discipline (Unrestrained)
Stress relief happens unclamped, dimensional change is larger than machining experience predicts. Rough, relieve, finish.
Sustained Hot-Wet & Press Fit
Hot-Wet: PA6 molecular weight falls within 10 days at 120 °C.
Press Fit: Unfilled grades grow 0.5–0.6% as they equilibrate; interference collapses.
Press Fit: Unfilled grades grow 0.5–0.6% as they equilibrate; interference collapses.
Sub-Zero Saturated Shift
Water absorption moves the glass transition from ~60 °C dry to ~−20 °C saturated, drastically changing low-temp behavior.
Processing Nodes
Process capability needs a defined specification, a stable process and observed data.
CNC Turning
CNC Milling
Boring / Grinding
Wire EDM
5-Axis Centres
Part Families
Bushings, bearings, wear pads, guide rails, Gears, sprockets, sheaves, cam followers, Spacers, insulators, fluid handling components, pump wear parts, structural brackets.
Request Engineering Review
Not sure which grade your print should call out? Send the function, load and service environment and the grade shortlist comes back in writing before anything is quoted.
Upload Drawing / SpecWhat Moves the Price of Machined Nylon Parts?
Process Economics
Setup and finishing, not raw material. On this class of work a touch-trigger probe cut fixture setup from a couple of hours to about 20 minutes, and a tooling change lifted feed from 9 ipm to 30 ipm roughing on the same glass-filled nylon part.14
Nylon machining cost is not published as a rate anywhere in this market, and for a good reason: custom CNC machining is typically quoted per drawing. Across the industry, price follows material, geometry, quantity and lead time rather than a fixed price list, and leading services accept orders from a single part. An exact figure for your part comes back in a written Zhenling quotation.
Six drivers that actually move the number
Effect on the numberRound bar versus plate versus near-net cast blank; how much you pay to turn into chips
Observed magnitudePA6 resin runs 10–20% below PA66 before any machining
Source / conditionPublished resin price comparison5
Effect on the numberFilled grades change tool material and tool life
Observed magnitudePCD inserts cost twice conventional carbide and returned five times the life on abrasive filled material
Source / conditionTrade-press shop account14
Effect on the numberCutter geometry sets achievable feed
Observed magnitude9 ipm to 30 ipm roughing and 20 ipm finishing at 500 rpm, same component
Source / conditionSame shop, same glass-filled nylon part14
Effect on the numberStepover collapses as the finish tightens
Observed magnitude0.0005–0.001 in stepover for a very smooth finish against 0.005 in where finish is not critical — 5 to 10 times the finishing passes
Source / conditionTrade-press shop account14
Effect on the numberFixture and datum work dominates below a few hundred pieces
Observed magnitudeProbing cut setup from a couple of hours to about 20 minutes; typical specialist batches run 35–70 pieces
Source / conditionTrade-press shop account14
Effect on the numberBoth are labour and oven time, not overhead
Observed magnitudePlastic resists tumbling — the material flaps rather than breaks — so some parts take hours of manual work; stress-relief cycles run 8–48 hours
Source / conditionTrade press15; patent cycle range10
Where small-batch cost actually concentrates
None of those is a Zhenling benchmark; they are published shop accounts, shown so you can see which levers a nylon machining cost estimate is actually sitting on. We will not claim a cycle time we have not run, and we will not compromise the distinction between what we have measured and what we have read.
Machining against injection moulding
That comparison is real, and the crossover is not a number anyone can hand you. Published economic studies analyse specific tooling routes that do not share a break-even point, and geometry moves the switch as much as volume does. We will not restate a single crossover quantity as a general threshold. Axes that actually decide it:
Annual quantity
Tooling amortisation against per-part cutting time.
Design stability
Every revision is free in machining and expensive in tooling.
Time to first part
Machining starts from stock, moulding starts from a tool.
Section geometry
Mouldable wall sections against features that only cutting reaches.
Material state
Machined parts start from stock with its own stress history; moulded parts carry a melt history instead.
How Long Does CNC Nylon Machining Take?
Three clocks run in series, not in parallel: machining, stabilisation and transit. Industry-typical machining runs 3–10 business days for prototypes and 1–3 weeks for small batches; a stress-relief cycle adds 8 to 48 hours10; sea freight adds roughly 30–65 days.
Why a nylon schedule carries a third clock
Steel has stress-relief heat treating too, so the difference is not that nylon has a step steel lacks. Nylon’s step differs because it is governed by moisture diffusion, and diffusion scales with the square of section thickness.
What that means in calendar terms:
ISO 1110 Accelerated Conditioning
Even the fast method needs at least one third of the thickness in millimetres squared, in days2.
Full Equilibrium
ASTM D618 puts substantial equilibrium at 20 to 100 days or more, thickness dependent9.
Ambient Equilibrium
At room temperature in ordinary air, PA6 can take years to reach equilibrium with its environment3.
Deliberate Conditioning
Collapses that from weeks or months to a couple of days1.
Thick Sections Issue
Thick sections are the problem case: the larger the volume, the longer to saturation3.
A conditioned solid cast PA6 test bar reached 50% RH equilibrium in 16 hours by the conventional procedure, and the same source flags thick objects as very lengthy.6 If your part must be measured at service condition rather than as-machined, that is a scheduled operation with a cost, and it belongs in the quotation rather than absorbed silently.
Where the time goes
Quotation
Instant to 24 hours
What extends it: Missing material spec adds 1–3 days; an incomplete request 3–5 days4.
Prototype machining
3–10 business days
What extends it: Fixture design on thin-wall or asymmetric geometry.
Small batch
1–3 weeks
What extends it: Setup count, finish requirement, inspection coverage.
Production
3–6+ weeks
What extends it: Stock availability in the specified grade and section.
Stress relief
8–48 hours oven time10
What extends it: Section thickness; ramp and soak schedule. (When specified)
Transit
Courier 2-5d / Air 7-12d / Sea 30-65d
What extends it: Lane and port; customs examination.
Expedite options are widely available across the industry, typically around a 25% premium for priority scheduling and more for compressed turnarounds, generally limited to simpler geometries and stocked material. Feasibility for your part is confirmed at drawing review.
Working to a fixed date? Send the print with the required delivery window and the three clocks come back separated, so you can see which one is actually binding.
Send the print
Who Carries Which Risk?
The dimension you accept, the state it was measured in, and the customs position are three separate risks with three different owners. Transaction value is the price actually paid plus exactly five named additions and no others16 — so a landed comparison is a calculable figure, not a guess.
Measurement state is where the disputes come from
This is the single biggest cause of disputes concerning machined nylon parts. A part that experiences several weeks of variable humidity is not in the same moisture condition on arrival as it was at inspection. It grows, but not evenly in all directions.
What the research establishes about that movement:
- Direction matters PA6 swelling is largest in the thickness direction and smallest in the length direction, and had to be modelled as orthotropic3
- Unfilled against filled unfilled grades behave close to isotropically, while glass-reinforced grades move much more transverse to flow than along it17
- Section thickness scales it maximum dimensional change varies with the part’s volume-to-surface ratio3
- Restraint creates stress uneven or inhibited swelling induces significant residual stress where wall thicknesses differ3
- The mechanism a saturated skin fights a still-dry core, and the dry bulk physically restrains the swollen surface layer3
How the responsibility is allocated
These are order mechanics, not a warranty. This sequence is fixed in the quotation before stock is cut:
- Parameter Lock Drawing review identifies the grade, the datum scheme, the achievable tolerance per feature and the measurement condition
- Governing Document Those parameters are written into the quotation, and the quotation is what governs
- Pre-run Confirmation Parameters are locked before material is released, so nothing is discovered mid-run
- First Article Acceptance Your first article is where you accept or reject those parameters, before batch release
- Batch Consistency Batch release follows acceptance, against the same recorded conditions
Landed cost is more than freight
A US buyer comparing an offshore quotation against a domestic one needs the customs position, and most of it is the buyer’s to determine. We can supply data; we cannot supply a classification or a duty rate, and we do not offer tariff advice.
HS classification & duty rate
Using a broker does not transfer liability; the importer remains responsible for entry correctness and all duties, taxes and fees.18
Inputs the classification needs
Country of origin, manufacturer, composition, intended use, and pricing — polymer grade and filler content are a customs input, not only an engineering one.18
Customs value
Price actually paid plus packing, selling commission, apportioned assists, royalties and resale proceeds — and no others.16
Your drawing package
Designs created in the United States and supplied to a foreign producer are outside the assist category.16
Buyer-supplied fixtures
Tools, dies and moulds supplied free of charge are a required addition even when made in the United States.16
Entry bond
Waiver is limited to shipments not exceeding $2,500, and expressly unavailable for merchandise the port director considers hard to appraise or classify.19
Origin marking on the part
The mark must be visible with casual handling, not concealed by later attachments, and readable without disassembly — a geometry constraint alongside your datums.20
Two items buyers routinely leave out of a landed comparison
A container examination is billed by a privately run examination station, and a complete devanning may cost several hundred dollars plus drayage and storage.18 On ocean shipments the Importer Security Filing is mandatory, and non-compliance risks penalties, added inspections and cargo delay.18
Commercial terms
Export machining orders from China commonly run on a 30–50% deposit with the balance before shipment, settled by telegraphic transfer. Most suppliers in export machining will sign an NDA on request, using either party’s template — raise it when you send the print. EXW, FOB and DDP are the typical Incoterms for machined exports across the industry; shipping terms are fixed in the quotation.
Building a landed comparison? Ask for the quotation itemised against these headings so your finance team can line it up against a domestic offer without re-deriving the components.
What Can We Evidence, And What Can We Not?
We can evidence a machining platform operating since 2006 and a documented metal record.
We cannot evidence a nylon production history, verifiable certification documents or in-house metrology — and in US federal source selection, an offeror with no relevant past performance is evaluated neither favourably nor unfavourably.21 That rule does not bind a commercial buyer, but it is the documented precedent for how this gap is normally weighed.
Our Boundary, Stated Rather Than Implied — The Honest Version
Publishing this boundary does not make us a better supplier. What it does is remove your verification cost: you do not have to go looking for a nylon record that does not exist.
LIMIT // 01
No Nylon Production History
Our documented record is metal machining. It is not restated here as plastics experience.
⤧
LIMIT // 02
No Named Certification On This Page
The CE and ASME marks in our profile sit in a pressure-vessel and metal scope. Neither endorses a machined polymer part, so neither appears as a credential here.
⤧
LIMIT // 03
No In-House Metrology Claim
We do not publish an inspection equipment list, and a contact probe deflects a low-modulus polymer under normal probing force in any case.
⤧
LIMIT // 04
No Public Case Studies
We hold no permission-cleared customer example to show you.
⤧
Evidence Objects: Proof Value And Limits
What It Can Support
Grade identity and the values that document explicitly covers
What It Cannot Replace
Finished-part dimensions or functional performance
What To Settle In Enquiry
Standard, grade designation, source, traceability level
What It Can Support
Typical properties for the stock as supplied
What It Cannot Replace
Acceptance limits for your feature
What To Settle In Enquiry
ASTM D4066 covers nylon as feedstock for moulding/extrusion, not finished-part acceptance22
What It Can Support
The measured characteristics and the stated conditions
What It Cannot Replace
Unmeasured features or internal soundness
What To Settle In Enquiry
Feature list, coverage, method, units and the measurement condition printed on the report
What It Can Support
Agreed characteristics on the released revision
What It Cannot Replace
Every subsequent batch
What To Settle In Enquiry
Which characteristics, whose acceptance, and what closes a deviation
What It Can Support
That approved controls carried forward
What It Cannot Replace
A characteristic nobody agreed to measure
What To Settle In Enquiry
Sampling rule, report format, lot linkage
Four Supplier Criteria, Answered Directly
01
Nylon-Specific Machining Experience
Our Position //
We cannot evidence this. No nylon production record exists to show you.
Click To Verify⤡
01
Verification Protocol
How You Verify It //
US federal source-selection practice scores absent relevant history as neutral rather than adverse21; it does not bind a commercial buyer, but it is the documented precedent.
Return⤢
02
Documented Quality Control
Our Position //
The controls are the ones written into your quotation: locked parameters, first article as the acceptance point, recorded measurement conditions.
Click To Verify⤡
02
Verification Protocol
How You Verify It //
Read them in the quotation before you release the order.
Return⤢
03
Design And Engineering Support
Our Position //
Drawing review returns the grade shortlist, the achievable tolerance per feature and the measurement condition — in writing, before quoting.
Click To Verify⤡
03
Verification Protocol
How You Verify It //
Send one print and judge the response.
Return⤢
04
Reliable Delivery
Our Position //
Three clocks quoted separately, with stress relief shown as real hours rather than absorbed.
Click To Verify⤡
04
Verification Protocol
How You Verify It //
Compare the quoted breakdown against the bands published above.
Return⤢
Hidden Costs & Commercial Terms
Two items buyers routinely leave out of a landed comparison: A container examination is billed by a privately run examination station, and a complete devanning may cost several hundred dollars plus drayage and storage.18 On ocean shipments the Importer Security Filing is mandatory, and non-compliance risks penalties, added inspections and cargo delay.18
Export machining orders from China commonly run on a 30–50% deposit with the balance before shipment, settled by telegraphic transfer. Most suppliers in export machining will sign an NDA on request, using either party’s template — raise it when you send the print. EXW, FOB and DDP are the typical Incoterms for machined exports across the industry; shipping terms are fixed in the quotation.
Want This Boundary Tested Rather Than Taken On Trust?
Building a landed comparison? Ask for the quotation itemised against these headings so your finance team can line it up against a domestic offer without re-deriving the components. Send one print and judge the engineering response — the grade shortlist, the achievable tolerance per feature and the measurement condition come back in writing before anything is quoted.
Engineering Toolkits
CORE SYSTEM
Launch Tool
Nylon Grade Selector
TOOL_02
Moisture Growth Calculator
TOOL_03
Lead Time Estimator
TOOL_04
Measured State Clause Generator
TOOL_05
Print Gap Audit
Questions Buyers Ask Before Releasing a Nylon Machining Order
Honestly, a tolerance is meaningless without its measurement condition. ISO 1110 states that reproducible polyamide values require a specified moisture content2, and ASTM D618 defines conditioning that is expressly not necessarily to equilibrium9. Send the feature, the section thickness and the service environment, and the achievable band comes back tied to a stated condition rather than as a headline number.
Work backwards from the failure you are trying to avoid. Dimensional criticality points to PA66 over PA6 for its lower moisture uptake and more predictable swell5. Thick sections and large blanks point to cast PA6. Stiffness under sustained load points to a glass-filled grade, at a measurable cost in achievable surface finish7. Dry sliding duty points to a filled-lubricated grade.
Yes, and the amount is quantified. Published 2013 guidance on unfilled nylon 6 and nylon 6/6 puts equilibrium moisture at 1.5–2% in ordinary 35–65% RH air with 0.5–0.6% growth; even a highly filled grade still expands roughly 0.1%, about 0.001 in per inch of dimension.1 Those figures were published for moulded parts, and the driver is the polymer rather than the forming process, so they carry across to machined stock — but the movement your part sees scales with its section thickness. This is why the measurement condition belongs on the drawing and on the inspection report.
It is typically quoted per drawing across this market, and the drivers are itemised above: stock yield, grade abrasion, tooling choice, finish requirement, setup share at small batch, and deburring and stress-relief hours. We publish the mechanism rather than a price, because the price for your part depends on your geometry and quantity and comes back in a written quotation.
They fail differently. Acetal is the more dimensionally stable choice in wet or humid service and holds tighter tolerances more predictably; nylon carries impact and abrasion better. If the part must hold a fit across a humidity swing, the moisture data above argues against unfilled nylon regardless of who machines it.
A preliminary discussion is possible, but a controlled quotation needs the acceptance information a model does not carry: revision authority, datums, tolerances, threads, finish, notes and inspection requirements. For nylon it also needs the measurement condition. If the model is authoritative, state how product-manufacturing information and acceptance criteria are communicated.
Whatever the enquiry scopes. Our evidence-object table above sets out what each document can and cannot prove, so the scope can be decided against what you actually need to release the parts — rather than against a document list that sounds reassuring.
Sustained hot-wet service is the clearest case. A 2024 comparative study of polyamide hydrolysis reports PA6 number-average molecular weight falling from 26.2 to 15.5 kg/mol within 10 days of ageing at 120 °C.12 That was laboratory immersion in water, not a service model, so it establishes that the failure mode exists rather than how fast it would arrive in your application. Press fits that must survive a humidity swing, stiffness that must not drift, and any optical requirement are the others.
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