CNC machining: The manufacturing & design guide
Learn about how the many different kinds of CNC machines work, the materials available, the benefits & limitations, basic design rules and the most common applications.
Read articleOn-demand CNC machining for rapid prototyping and production parts, through a network of specialized, experienced and thoroughly vetted CNC machine shops.
Get instant CNC machining quote All uploads are secure and confidentialWe operate almost every kind of CNC mill and turning center, and pride ourselves on being able to machine whatever you need, from simple, ‘as-machined’ workholdings to complex, organic geometries with tight tolerances. On request, we can also produce parts with EDM and grinders. Build envelopes, minimum feature sizes and design guidelines vary for milling and turning.
Our network has over 1,000 milling centers, including standard 3-axis mills, indexed 3+2-axis mills & fully-continuous 5-axis mills.
Tolerances from 0.05mm (0.0020 in)
Lead times from 5 business days
Our network has over 300 turning centers, including Swiss lathes and multi-axis mill turns.
Tolerances from 0.05mm (0.0020 in)
Lead times from 5 business days
We machine rapid prototypes and low-volume production orders for customers in multiple industries: aerospace, automotive, defense, electronics, hardware startups, industrial automation, machinery, manufacturing, medical devices, oil & gas and robotics.
We can generate instant machining quotes for 50+ metals and plastics.
Aluminum 6060 | AlMgSi Aluminum 5052 | AlMg2,5 Aluminum 2017 | AlCu4MgSi Aluminum 2014 | AlCu4SiMg Aluminum 6063 | AlMg0,7Si Aluminum 7050 | AlZn6CuMgZr Aluminum 2024-T351 | 3.1355 | AlCu4Mg1 Aluminum MIC6 Aluminum 7075-T6 | AlZn5,5MgCu Aluminum 5083-H111 | 3.3547 | AlMg4.5Mn0.7 Aluminum 6082 | AlSi1MgMn Aluminum 6061-T6 | AlMg1SiCu See all alloys
Stainless steel 416 Stainless steel 15-5 Stainless steel 301 Stainless steel 430 Stainless steel 440C | 1.4125 | X105CrMo17 Stainless steel 420 Stainless steel 304/304L | 1.4301 | X5CrNi18-10 Stainless steel 2205 Duplex Stainless steel 17-4PH Stainless steel 303 | 1.4305 | X8CrNiS18-9 Stainless steel 316/316L | 1.4404 | X2CrNiMo17-12-2 See all alloys
Steel S235JR | 1.0038 Carbon steel EN8/C45 | 1.0503 | Fe Steel S355J2 | 1.0570 Mild steel 1045 Mild steel A36 Mild steel 1018 See all alloys
Brass C360
Copper C101 Copper C110
Alloy steel 1.7225 | 42CrMo4 Alloy steel 1.7131 | 16MnCr5 Alloy steel 1215 Alloy steel 4340 Alloy steel 4140 See all alloys
Tool steel A3 Tool steel H13 | 1.2344 Tool steel S7 Tool steel O1 Tool steel A2 | 1.2363 Tool steel D2 | 1.2379 See all alloys
Titanium Grade 5 | 3.7164 | Ti6Al4V Titanium Grade 2 Titanium Grade 1
Inconel 718
Invar
We can generate instant quotes for 10+ surface finishes.
Instead of traditional, rules-based quoting, we use machine learning algorithms to compare your CAD to millions of previously manufactured parts and generate a quote instantly.
Upload a CAD to start (STEP, STP, IGES, IGS, SLDPRT, 3DM, SAT, STL, OBJ or X_T)
Price updates in real-time as you change materials, lead time, etc..
No hidden costs. Our instant quotes are not just indications, but the actual price, and include shipping and customs up front.
Hubs takes the stress out of manufacturing by guaranteeing the quality and consistency of every part. Each order is dimensionally and visually inspected by our in-house quality control team to make sure it meets the Hubs Standard. If you’re not satisfied with your order, we’ll remake your parts as fast as possible, free of charge, or refund you - whichever you prefer.
Our platform accelerates prototyping development cycles by reducing pre-production admin from weeks to minutes:
Instant quotes
Instant DFM feedback
Online quote and order management
Live production and delivery tracking
Our platform is designed to be so intuitive that you can order your parts quickly and efficiently without any assistance. But if you ever need us, we're here to help.
For production orders, we have full-service teams ready to guarantee identical specs on every order for the best unit price:
Dedicated project managers in your time zone
Application engineers for DFM cost optimisations
First Article Inspection (FAI)
Manufacturing is about relationships, so we have staff on the ground wherever you are to help make sure everything runs smoothly and on time, every time.
Hubs simplifies the process of sourcing custom machined parts. We offer you the capacity and capabilities of dozens of machine shops, with the ease of dealing with one. You get the experience and specialisation of all our partner shops, we handle all the communications, delivery, quality control and customs.
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We use automation to make custom machining easier, faster and more affordable than traditional machine shops:
We have an incredibly broad range of capabilities - much more than most individual shops.
Our quotes are generated instantly - request as many quotes as you like without feeling guilty.
No hidden costs - all costs are included in our quotes and we always commit to the pricing shown.
No limits on order size - we can scale with you from one-off prototypes to millions of production parts.
We leverage market forces within our network to guarantee competitive pricing on every order.
In January 2021, Hubs was acquired by Protolabs, joining forces to build the world’s most comprehensive online manufacturing platform.
Protolabs offers lightning-fast manufacturing with its automated in-house machines. The digital manufacturer is a great choice for geometrically simple (3- and 5-axis milling) parts and time-sensitive projects.
Interactive quotes with design analysis
The fastest turn-around in market (as fast as 1 day)
US export controlled parts (ITAR) or critical parts
Ideal for prototypes and small volumes of end-use parts
Hubs offers an incredible range of manufacturing capabilities and can support both one-off prototyping and full-scale production quantities. Hubs is the best manufacturing solution for geometrically complex parts (5-axis) and secondary operations such as specific surface finishes.
Instant online quotes
The widest breadth of capabilities, with 59 materials and 15 surface finishes (ISO-9001)
High-precision machining, with tolerancing down to 0.1 for plastics and 0.05 mm for metals (ISO 2768)
Going from prototype to production
Competitively priced for serial production
We guarantee that our manufacturing partners follow ISO 2768 standards for all CNC machined parts. Parts machined with metal will follow ISO 2768-m (medium) or ISO 2768-f (fine). Parts machined with plastics will follow 2768-m (medium). Geometric tolerances down to ± 0004 in. (0.010 mm) are possible but must be clearly indicated in technical drawings. We can achieve tighter tolerances on shafts with up to H7 fits with manual quoting and on occasion tighter.
At Hubs we offer CNC milling (3-axis, 3+2-axis and 5-axis) and turning. Milled parts can be machined up to 2000 x 1500 x 200 mm (78.7 x 59.0 x 7.8 in.) for 3/3+2 axis CNC milling. For 5-axis milling, the maximum part size is 650 x 650 x 300 mm (25.5 x 25.5 x 11.8 in.). The maximum diameter for CNC turning is 431mm (17 in.), length 990 mm (39 in). Minimum part dimensions recommended are around 0.39 x 0.39 x 0.39 in. (10 x 10 x 10mm).The minimum for feature dimensions is 0.5 mm.
We are limited to a 1000 mm (39 in.) maximum size for parts on our platform. If you need higher dimensions, you can place the request through your account manager.
Deburring and edge breaking are standard procedures for all CNC machined parts. If there are any critical edges that should be left sharp, they must be clearly indicated in technical drawings. Surfaces will be free of defects such as scratches, dents, stains, blemishes, hanging marks, minor defects. Surfaces indicated as critical (primary (a) side, as indicated on the technical drawing) will be free of mill steps and other marks. For the secondary (b) side, minor hanging marks and up to 2 minor defects are acceptable. A number of post-processing and finishing methods can be applied to improve the surface roughness, visual properties and wear resistance of machined parts.
We use machine learning algorithms to calculate the exact cost of any machinable part directly from a CAD file, based on millions of CNC machining orders we’ve previously processed. No more waiting for technicians to get back to you via email, we can generate an exact quote for you instantly (well, in about 5 seconds).
This means you always know the price up front. Simply upload a CAD file to generate a quote: get an instant CNC machining quote . Our quotes are completely free, you only need to create an account so we can protect your IP.
It’s so easy to use that we encourage mechanical engineers to use it constantly as they optimize their designs for cost. Whenever you’ve made a new design iteration, simply load both the old and the new design into our quoting tool and see if the price is different.
This technology means our manufacturing partners also don’t need to do their own machining quotes, which means less overhead for them. This makes the whole process less expensive, which translates into lower prices for our customers.
The main costs associated with CNC machining can be grouped into machining time, start-up costs, material costs, and feature costs. To reduce costs you need to understand the impact of these factors on cost.
The best way to reduce machining time is to design features that can be machined quickly, for example by choosing the correct radii for internal corners, reducing cavity depth, increasing wall thicknesses, limiting thread length and designing holes with standard sizes.
Material costs can be reduced by considering the size of the blank required, and the cost and machinability of the bulk material (softer alloys are faster to machine).
Start-up costs can be reduced by reducing the number part rotations or repositioning required to finish the part, for example by separating geometries into multiple parts that can be assembled later.
Feature costs can be reduced by only using tolerances when strictly necessary, removing all text & lettering, and avoiding multiple surface finishes.
These tips can be read in more detail in our full guide to reducing the cost of CNC machined parts.
We use algorithms to identify the best manufacturer in our network for your specific order, based on their proximity to you, their experience with similar parts and their available capacity right now. This allows us to balance our customers’ demands for speed, cost and quality better than ever before.
Hubs was started by mechanical engineers and we have many more engineers and technicians in our team. Together we’ve written a lot of content on CNC machining over the years. You can find a selection of resources below, or you can head to our knowledge hub and filter on CNC machining to read case studies, in-depth design guidelines and explanations of different surface finishes.
We’ve also written a complete engineering guide to CNC machining. Here you can learn about how the many different kinds of mills and lathes work and the different materials available, so you can easily compare their benefits & limitations. You’ll also learn the basic design rules for machining and the most common applications of each material and surface finish, so you can make the right choices every time.
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