How Much Does Online CNC Machining Cost? File Formats, Materials, Finishing & Quotes

Online CNC machining is a subtractive manufacturing process where computer-controlled tools cut a part from solid material to exact dimensions, ordered remotely from a supplier or platform rather than a local shop.

Three choices made before submitting an RFQ decide whether the factory quotes the actual part or a guess at it: file format, material, and surface finish. Getting any of the three wrong leads to a re-quote, rework, or a misinterpreted part.

This guide covers accepted file formats, material and finish options with their cost impact, what drives a CNC quote, and how to check a quote against the factory's verified capability.

 

What file formats are accepted by online CNC machining services?

Online CNC machining services accept STEP or IGES files for the 3D model, plus a PDF 2D drawing for tolerance and finish callouts. STEP is the format CAM software machines from, so it is the file an RFQ must carry.

• STEP / IGES: Solid-body CAD; this is what CAM software machines from, and what an RFQ must carry.
• PDF 2D drawing: Carries the tolerance callouts and surface-finish specs that 3D geometry alone cannot express.
• STL / OBJ / 3MF: Surface meshes; fine for 3D printing, risky for machining because the mesh approximates the true surface and can silently alter the part.

Export the STEP file at the final dimensioned state, not the raw body. Include critical dimensions and GD&T callouts on the 2D drawing so the factory scopes the job correctly instead of guessing.

How online CNC providers' file formats compare

In Haizol's review of 14 online CNC providers' published upload and help-center documentation, we found that 100% of providers accept STEP/STP for the 3D model — it is the only universally supported format. The other formats diverge:

• IGES: accepted by 57% of providers (8 of 14). Fictiv is the only one that explicitly rejects it, while the rest that don't accept it simply don't list it.
• STL / OBJ for CNC: accepted by 50% of providers (7 of 14), and even where accepted it's often restricted. PCBWay, Hubs, SendCutSend, and Fictiv explicitly reject mesh formats for CNC work, accepting them for 3D printing only, meaning ~29% of providers won't machine from a mesh at all.
• File-size limits: range from ~10 MB at Fictiv (the lowest) to 200 MB at Haizol, a 20x spread across the market.

The practical takeaway: STEP/STP is the safe universal upload, IGES works with just over half of providers, and a mesh is the most likely to be rejected for machining.

Provider	3D CAD Formats	2D Drawing Formats	Max File Size
Haizol	STEP, IGES (RFQ also accepts DWG, PDF)	DWG, PDF	200 MB/file
Xometry	STEP, STP, SLDPRT, STL, IPT, X_T, X_B, 3DXML, CATPART, PRT, SAT, 3MF, JT	DXF, PDF	100 MB
Protolabs	IGES, STEP, SLDPRT, PRT, X_T, X_B, SAT, 3D DWG, IPT, CATPART, STL*	PDF (attached)	None stated
Fictiv	IPT, SLDPRT, 3DXML, CATPART, PRT, X_T, X_B, STP, STEP (+ ~15 niche); IGES not accepted	PDF only (must attach to CAD)	~10 MB
RapidDirect	STEP, STP, STL, IGS, IGES, PRT, SLDPRT, SAT, X_T	PDF	15 MB
JLC CNC	STEP, STP (mandatory)	PDF, DWG, DXF	None stated
PCBWay	IGES, IGS, PRT, STEP, STP, X_T, SLDPRT	PDF, SVG, JPG, PNG, DWG, DXF	50 MB
Hubs	STEP, IGES, SLDPRT, 3DM, SAT, X_T	PDF	None stated
SendCutSend	STEP, STP (instant); more for custom RFQ	DXF, DWG, EPS, AI	No general max
WayKen	STEP, IGES, X_T, STL	DWG, PDF	None stated
Weerg	STEP, STP (instant); STL for custom only	PDF; DXF for custom	150 MB
Geomiq	STEP, STP, IGS, IGES, STL	DXF, PDF, DWG	None stated
Fractory	STP, SLDPRT, IPT	DXF, PDF	None stated
3ERP	STEP/STP, IGES/IGS, STL; more for laser cutting	PDF, DWG, DXF	None stated

 

What materials are supported by online CNC services?

Online CNC services machine aluminium, stainless steel, carbon steel, brass, titanium, tool steel, nickel alloys, and engineering plastics such as POM, ABS, and PEEK. Machining cost rises steeply from aluminium 6061 to titanium and PEEK, so the specific grade matters more than the metal family.

Haizol's review: how online CNC providers' materials compare

In Haizol's review of 15 online CNC providers' published capability pages, we found that 100% of providers machine aluminium — it is the only universally supported metal family. Stainless steel and carbon steel follow at 93% each, and 93% of providers offer nylon/engineering plastics. The selective materials are titanium at 80% and PEEK at 67%, the most restrictive engineering plastic.

Provider	Metals	Plastics	Stated total
Haizol	Aluminum (2024, 5052, 6061, 6082, 7075), stainless (303, 304, 316, 17-4PH, 2205), carbon steel (1018, 1020, 1045), alloy steel (4140, 4340), tool steel (A2, O1, D2, SKD11), titanium (Gr1, 2, 5, 23), brass, copper, bronze, Inconel 718	ABS, PC, PP, PE, PA/nylon, POM/acetal, PMMA, PBT, PVC, HDPE, PEEK, Ultem/PEI, PPSU	75+
RapidDirect	Aluminum (6061, 6061-T6, 2024, 5052, 5083, 6063, 6082, 7075, 7075-T6, ADC12/A380), copper, brass, bronze, steel (1018–4340, A36 + more), stainless (SUS201–630, 304), magnesium (AZ31B, AZ91D), titanium (TA1, TA2, TC4)	~40 named plastic variants incl. ABS, ABS+PC, PC, PMMA, POM, PA/Nylon (+ glass-filled grades), HDPE, UHMW-PE, LDPE, PEEK, PP, PBT, PAI, PET, PPS, PS, PVC, PTFE, Bakelite, FR-4	30+ materials
Xometry	Aluminum (2024, 5052, 6061, 6063, 7050, 7075, MIC-6), copper, brass, bronze, stainless (15-5, 17-4, 303, 304, 316/316L, 410–440C), steel (1018–A36, A2/O1 tool steel), titanium (Gr2, Gr5), zinc	ABS, acrylic, acetal/Delrin, Garolite G10/G11, HDPE, Nylon 6/6, PC, PEEK (+GF30, USP Class VI), PP, PTFE, UHMW-PE, PVC, Ultem 1000/2300	Over 40 / "50+ metals, alloys & plastics"
Protolabs	Aluminum (6061, 7075, 2024), brass (C260, C360), copper (C101), 1018 steel, stainless (17-4PH, 303, 304/304L, 316), 4140 alloy steel, titanium (Gr5)	ABS (+FR), CPVC, HDPE, Nylon 6/6/6, PC (+GF20), PEEK, Ultem 1000/2300, PET, PMMA, POM-H/C (+GF20, ESD), PP homo/co, Noryl PPE+PS, PPSU, PTFE, PVC, UHMW-PE	30+
Fictiv	Aluminum (6061-T6, 7075-T6, 3003, 7050, 2024, 5052, 6063, MIC6), bronze, brass, copper, cast iron, magnesium, titanium (Gr2), Invar, Kovar, zinc/Zamak 3, stainless (15-5, 420, A286, 17-4), steel (12L14, 1215, 8620, A36), D2 tool steel	ABS, acrylic, Delrin/acetal, Garolite G-10, nylon, PEEK, PC, PP, PPS, PTFE, PVC, Torlon/PAI, UHMW-PE, Ultem	68 unique materials (2022 figure)
JLC CNC	Aluminum (6061, 7075), stainless (SUS304), 45# steel, brass (H59), copper (T2)	ABS, FR4, Nylon-PA6, PC, PMMA, POM, Bakelite	13 items listed
PCBWay	Aluminum (6061, 7075, 5052, 2A12), stainless (304, 316, 303, 430, 201), brass (C360); copper, mild/alloy/tool/spring steel, titanium	ABS, Nylon 6/66, PC, POM/Delrin, PTFE, HDPE, PEEK, PE	Over 50
Hubs	Aluminum (~19 grades), stainless (~13), bronze, carbon/mild steel (~9), brass, copper, alloy steel (~9), tool steel (~9), titanium (Gr1, 2, 5), Inconel 625/718, Invar 36	POM-C/H (+FDA, ESD), Nylon 6 (+FR, GF), Nylon 6/6 GF30, PPSU, ABS, PEEK (+GF30), PTFE, PC, UHMW-PE, HDPE, PVC, PMMA, PET, PP (+GF30), Garolite G-10/FR4, Ultem 1000/2300	75+
SendCutSend	6061-T6 aluminum only ("more coming soon")	None listed for CNC	1 material currently
WayKen	Aluminum, steel, stainless, brass, bronze, copper, magnesium alloy, titanium alloy, zinc alloy (no specific grades)	ABS, PC, ABS+PC, PMMA, PA/nylon (+GF30), POM/Delrin, PP, PVC, HDPE, PPS, PEEK, PEI/Ultem, Teflon, Bakelite, epoxy tooling board	More than 30
Weerg	Aluminum (5083, 6082, 7075, 2011, 2017A, 7021, 7022), stainless (303, 304, 316L), structural steel (S235JR, S355J2), C45, copper (C101), bronze (CuSn12), brass (OT58)	Polyethylene, PTFE/Teflon, PVC, PEEK, POM-C, Nylon 6+MoS2, ABS	Over 30
Geomiq	Aluminum (6082, 7075-T6), stainless (303, 304, 304L, 316, 316L), copper, brass (CZ121, CZ131), magnesium (AZ31), 4140 alloy steel, D2 tool steel, titanium (Gr5)	Nylon 6 (only one named on-page)	Over 100
Fractory	Steel, stainless steel, aluminum, titanium (no grades stated)	Nylon, POM, PE (no grades stated)	Not stated
Jiga	18-8/300-series stainless, 301–904L grades, aluminum (355, 6061, 7075), steel (EN10130, ST37, A36, A2), Elgiloy, Hastelloy C276, titanium (Ti-6Al-4V, ELI), ToughMet, tungsten/tungsten carbide, wrought iron, zinc	ABS, acrylic, Chirulen/UHMW-PE variants, Delrin (+100AF), Nylon 6/66, PE, PEEK (+450G, CF30), PEI, PES, PET, PFA, PMMA, PA6 GF30, PC, PP, POM/acetal/Delrin, PPS, PPSU, PTFE, PVC, PAI, Garolite G-10	Not stated
3ERP	Aluminum (7075-T651, 6061-T6, 6082-T651, 5052, 2017, 2024), brass (H59, H62, C260, C360), copper, steel, stainless (416–2205 Duplex), bronze, titanium (Gr1, 2, 5), magnesium (AZ31B, AZ91D +), zinc (Zamak 3, 5), Inconel (601, 625, 718), Invar (32-5, 36, 42)	~30 named variants incl. ABS, ABS+PC, PMMA, PC (+GF30), POM, PA/Nylon (+GF15/30), PP (+GF30), PTFE, PEI, PS, PPS, PE, PPSU, PET, PEEK, LDPE, G-10/FR4, HDPE, PVC	Over 60

 

Do online CNC services offer surface finishing and post-processing?

Yes, online CNC services offer surface finishing and post-processing, including deburring, bead blasting, anodising, powder coating, plating, and polishing. As-milled is the cheapest option, and every added finishing step raises the part price.

Finish	Cost impact
As-milled	Baseline
Deburr, bead blast	Low addition
Anodizing / powder coating (clear, colored, functional)	Moderate addition
Multi-step plating / polishing (electroless nickel, electropolishing)	Higher addition

 

How Much Does Online CNC Machining Cost?

CNC part price is driven by tolerance class, order volume, material, surface finish, and design complexity. Tolerance class and order volume have the largest effect on unit price.

• Tolerance class. Standard commercial tolerance is commonly ±0.127 mm (ISO 2768-m). Precision tolerance with GD&T callouts adds roughly 15–40% to price, and high-precision or EDM work (±0.002–0.005 mm) adds 40–100% or more. Tighter tolerances also shrink the supplier pool, so the price rise comes with fewer factories able to quote.
• Volume. Volume discounts average 37.4% at roughly 10× quantity and 53.8% at roughly 100×, per Haizol's China CNC Machining Industry Report 2026, and 99.6% of suppliers offering tiered pricing applied a systematic discount. Small runs are not penalised for being small: 43.3% of RFQs in the report were for 1–5 units, and those still drew 18.7 quotes on average.
• Material, finish, and lead time. Hard-to-machine materials and multi-step finishing push cost up; repeat volume and simple 3-axis geometry pull it down. See the material cost table and provider comparison in the materials section above.

Most buyers over-specify tolerances. Tight GD&T belongs only on fit, function, and safety-critical features; standard shop tolerance covers everything else. Request two or three quantity tiers (for example 10 / 100 / 1,000 units) to map the full cost curve.

How Do You Compare CNC Quotes Against Factory Capability?

A CNC quote should be evaluated against the factory's ability to make and inspect the part, not against price alone. It is a good practice to verify the factory's machine list, QC equipment, certifications, and capacity data needed to judge whether a quote is credible as well as competitive.

• Check the machine list against the tolerance claim. A factory quoting ±0.025 mm with no CMM (coordinate measuring machine) listed under QC equipment cannot verify that tolerance, so the claim is not auditable.
• Check remaining capacity against the quoted lead time. A factory at 92% utilisation quoting 15-day delivery is not being realistic.

Use Haizol's verified factory profiles. Every machining manufacturer in China listed on the marketplace has its machine list, certifications, and capacity data independently confirmed before it can receive an RFQ. 90% of RFQs submitted through Haizol receive quotes from 8 or more verified factories within approximately 24 hours.

1. Open the RFQ dashboard

Log in, click the profile icon in the top-right corner, and select "RFQs" from the dropdown.

2. Select the part

The dashboard lists every part you've submitted for quoting. Click the one you want to review to open its RFQ detail page.

3. Open the Quotes tab

Click "Quotes" to see every response from verified factories, with price, lead time, and a link to each factory's profile.

Quotes appear side by side, so price differences are visible immediately. Open the profile behind any quote that looks too low or too fast.

4. Check the machine list against the tolerance claim

A factory quoting ±0.025 mm with no CMM listed under QC equipment can't verify that tolerance. The claim isn't auditable, whatever the quote says.

5. Check capacity against the quoted lead time

A factory at 92% utilisation quoting 15-day delivery isn't being realistic. Prefer a longer lead time from a factory with room over a short one from a factory that's full.

For what to put in the RFQ so the quotes are comparable in the first place, see How to Get Accurate CNC Machining Quotes From China.

Ready to get comparable CNC quotes? Submit an RFQ on Haizol and compare quotes from verified, certification-matched factories within 24 hours.