Nylon is a resilient and flexible engineering plastic material. It is exclusively used for making gears, bearings, and mechanical housings. However, Machining nylon exhibits different characteristics compared to machining metals and other rigid plastics. Its low melting point and high elasticity can cause dimensional shifts, surface burns, and tool marks.
Therefore, controlling heat and tool pressure is crucial to maintain shape accuracy. Engineers often face the challenge of keeping tolerances tight and surface finishes consistent when producing nylon parts for functional assemblies.
At FastPreci, we approach nylon machining with meticulous care. Our engineers adjust cutting speeds, tool geometries, and coolant flow to manage heat and reduce material stress. Each part goes through a DFM review before production to ensure stability and accuracy.
Using advanced 3-, 4-, and 5-axis CNC machines, we achieve tolerances down to 0.005mm even on flexible nylon grades. With ISO-certified quality systems, rapid lead times, and cost-efficient production methods, FastPreci helps you get durable, dimensionally stable nylon parts.
In this article, we will walk you through nylon, its machining techniques, applications, and useful tips to effectively machine nylon. So, keep on reading.
What is Nylon?
Nylon is a strong and lightweight engineering thermoplastic. It belongs to the polyamide family. It is composed of synthetic polymers. It offers high tensile strength and good design freedom and flexibility. Nylon resists wear and abrasion, which makes it useful for moving parts. Moreover, it also absorbs impact and withstands repeated stress without cracking.
You often find nylon applications in gears, bearings, spacers, and fasteners. It works well in both dry, lubricated, and hostile conditions. The material’s low friction helps reduce noise and vibration in assemblies.
Nylon also has good chemical resistance and maintains stability under moderate heat. Because of its strength, toughness, and low weight, engineers use nylon across automotive, electrical, and consumer product applications.
Comparative Properties of Machinable Nylon Grades
Here are the common types of machineable nylon grades and their properties.
| Material Property | Nylon 6 | Nylon 6/6 | 30% Glass-Filled Nylon 6 |
| Density (g/cm³) | 1.12–1.15 | 1.14–1.17 | 1.34–1.39 |
| Tensile Strength (MPa) | 65–85 | 85–95 | 145–185 |
| Elongation at Break (%) | 55–95 | 45–65 | 2–6 |
| Flexural Modulus (GPa) | 2.4–3.1 | 2.9–3.3 | 7.2–8.8 |
| Impact Resistance (J/m) | 45–75 | 55–85 | 85–125 |
| Hardness (Rockwell R Scale) | 110–118 | 115–123 | 122–130 |
| Heat Distortion Temperature (°C) | 65–85 | 85–105 | 175–195 |
| Thermal Expansion Rate (µm/m·K) | 85–105 | 70–95 | 22–42 |
| Moisture Absorption (%) | 1.6–2.1 | 1.1–1.6 | 0.9–1.3 |
| Melting Range (°C) | 215–225 | 250–265 | 215–225 |
Machining Nylon: Step-by-Step Process
Before getting deeper into details about nylon applications, it’s crucial to understand how to machine nylon.
Choose the Right Nylon Grade
At first, you must know about the intended application of your part. Nylon is available in various forms, and each of them has a different performance. For example, nylon 6 is softer and easier to work with. Nylon 66 remains strong even under extreme temperatures. Glass-filled nylon is useful for parts that require increased stiffness or enhancement of wear strength. By deciding in advance what sort to use, you save yourself future inconvenience and time loss.
Store and Condition the Material
Nylon readily absorbs moisture from the atmosphere, and as a result, its dimensions change. Never forget to look at whether your stock is wet or not, or is uncovered. Oven-dry it and leave it to cool down. It is advised to store your nylon stock in containers or packages. Its machining gives accurate and stable results when you start with already conditioned dry material.
Inspect and Prepare the Stock
Always inspect your raw material stock. Any uneven ends, cracks, or dents can influence the part’s accuracy during machining. Wait and cut ends, which leave the level in the vise. This basic test allows you to keep your cuts straight and not messy.
Select the Right Tools
Use the right and sharp tools. Incorporate high-speed steel or polished carbide cutters of positive rake angles. Sharp tools take in heat that can either melt or deform the surface. You should wipe and clean your tools between turns to keep the work going.
Secure the Workpiece
Gently clamp the nylon to avoid compression. Grasp the item/product firmly so that it does not move, yet firmly so that it is not easily bent. Where needed, soft jaws or pads are to be used. When dealing with large components, it should also be supported to avoid vibration.
Set Proper Speed and Feed
It is a matter of trial and error before getting the appropriate balance. Excessive speed produces heat, slowness produces crudities. The formation of the chips must be prohibited; they ought to be clean and not melted. Check and re-tighten fixtures after initial cuts.
Manage Heat and Chips
Nylon can easily get spoiled by the heat. Apply compressed air and fine mists in place of heavy coolant. Nylon takes up moisture. Monitor the cut and fine-tune for no melting. Otherwise, they will adhere to the surface and can impact the finish.
Plan Roughing and Finishing Cuts
Start hewing to take away excessive material and leave a small margin for finishing. In the last pass, introduce light cuts with constant feed rates. Climb milling usually gives a smoother finish and puts less load on the part.
Drill, Ream, and Tap with Care
Remove the drill bit from the hole and then clear out the chips. Turn it on gradually to prevent heat accumulation. In reaming, clean tools and light pressure must be used. Nylon can be a big drag when tapping, so it is a big difference when one is dealing with a soft touch and a small amount of lubricant.
Deburr and Clean the Part
After cutting, inspect all edges of burrs. Sharp tools, such as a knife or scraper, should be used in place of power tools to avoid surface heating. Clean the part with a dry cloth. Do not forget to leave the final check to dry.
Inspect the Final Dimensions
Allow the part a brief rest period, then measure. Nylon machined parts can be expanded. Check vital points and verify tolerances. Having regular checks will assist you in keeping accuracy on repeats.
Package and Store Properly
When checked, wrap every part to avoid scratches and dust. Keep the stock in a cool and dark space where it will not absorb water. Don’t stack heavy parts on top. A little attention now holds the finish and fit just right during the use of your parts.
CNC Techniques for Machining Nylon Parts or Components
There are different CNC methods used to produce nylon parts. Each process works best for specific shapes and tolerances. Because nylon is soft, it needs sharp tools and controlled cutting to avoid heat damage. Here are the common techniques employed for machining nylon.
CNC Milling
In the milling of the nylon, the primary step is setting up the tool. Engineers choose the sharp single-flute or two-flute carbide cutters because nylon produces long and stringy chips. A tool with a dull edge often causes friction. With cutting, the spindle rotates at high speed, with a moderately constant feed rate to avoid rubbing. Instead of a liquid coolant, you can use air or mist cooling as an anti-moisture agent.
The operator makes numerous shallow cuts as opposed to a single deep cut. This cools the component and avoids the warpage. Following roughing, a light finishing pass follows to smooth the surface and correct tool deflection. Precision faces, grooves, or intricate 3D contours are usually machined by milling. Nylon components can be used to reach tight tolerances and can come right out of the machine with glossy finishes.
CNC Turning
When making nylon parts, make sure the rod stock stays firmly in the lathe’s soft jaws. This helps prevent the rods from bending and deforming. It has a mount with a sharp carbide tool of positive rake, and spindle speeds of 1500-3000 RPM are typical. The saw is very gentle in cutting the material, as it cuts it rather than compresses it. This is maintained at constant temperature by continuous air cooling of the surface.
During finishing, check the part for deflection. Because nylon can spring back slightly after being cut. Internal bores are frequently cut a little smaller to allow for stabilization in the appropriate dimension. Turning is used for roller making, bearings, and sleeve components. When properly done, the finish is light and smooth without secondary polish.
CNC Drilling
Nylon drilling starts with the appropriate bit choice. Best drills include:
- Parabolic-flute drills
- Brad-point drills
Both of these are good for clearing chips and help avoid nylon melt. The spindle speed remains moderate, and operators apply brief peck sessions where the chips and heat are released. Air blast is used to cool the drill tip between pecks.
After the hole is filled in, engineers allow the part to cool, after which the size is checked. On returning to the room temperature, nylon will shrink to a small extent. In case perfect holes are required, the reaming and boring pass has to come after stabilization. Proper drilling provides good edges with no white burns, implying that the temperature was controlled within the controlled limits.
CNC Routing
Routing is commonly used to cut nylon sheets or profiles. A sheet is placed on a vacuum table, or it is clamped hard to prevent shivering. They are Pierce using a high-speed router whose bit is spiral and has a cut edge. Its spindle speed is approximately 18,000- 22,000 RPM whilst the feed rate is adjusted to ensure no friction and melting of the edges is experienced.
A minor layer of material is removed in each pass to minimize heat. The air flow ensures the keep tool and nylon cool. When routed, the edges are ensured for smooth without burrs. Routing applies best on panels, guards, and flat components that are in large components, and where the look and the edge quality are of the essence.
CNC Sawing
The preparation phase before final machining is sawing nylon. A fine-tooth blade (typically 10-14 TPI) is used on a bandsaw. The material is fed gradually to ensure that the blade speed is low so that it does not get heated up. Short stops between cuts or air cooling can serve to preserve a clean cut.
Sawing makes flat, square blanks. These blanks have extra material for later processing steps. The saw cut can be clean, appropriate for milling or turning, and more accurate in subsequent operations.
What are the Tooling Requirements for CNC Machining Nylon?
As mentioned before, CNC machining allows close precision and a smooth finish for nylon parts. However, it’s not as easy as it seems, as there are various things to account for. All of the tools, speeds, and means of cooling are involved to ensure that the parts are produced accurately and stably.
Tool Material Selection
Most nylon machining jobs are done using high-speed steel tools. These tools remain sharp and make smooth cuts. In the case of glass-filled nylon, tungsten carbide tools provide a better performance. These are long-lasting and deal with rough clothes without becoming worn out too quickly. Carbide tools are also effective when it comes to manufacturing a large quantity of nylon parts.
Tool Geometry Considerations
There are several aspects of the tool geometry to consider. The tool shape influences the way in which nylon cuts. High rake angle assists the tool in penetrating the material using less force. Flutes with a polished tool remove chips fast and leave the surface clean. These characteristics lower friction and heat, and as a result, the nylon does not melt or adhesively stick to the tool.
Cutting Parameters
Nylon machines are most effective in cutting 100 to 300 meters/min. The feed rate is recommended to be about 0.1-0.4 millimeters per revolution. In the case of glass-filled nylon, lower speeds aid in the control of heat and preserve the quality of surfaces. It is better to maintain these settings during machining nylon for optimum outcomes.
Cooling Methods
Nylon should be air-cooled before machining. This prevents moisture buildup and keeps the part cool. In general, nylon absorbs water, and its size and shape change when water-based coolants are used. Dry cutting or compressed air keeps parts accurate and minimizes the possibility of swelling.
Tool Maintenance
Nylon, particularly glass-filled ones, may wear out cutting edges. Checking and tool replacement should be done regularly when they become dull. This keeps the final product uniform with consistent quality. Timely maintenance also increases the longevity of tools and reduces machining expenses.
Common Machining Nylon Parts Across Different Industries
Nylon is a light and powerful material that is employed in various industries. It is durable to wear, heat, and stress, and this makes it an ideal option to use in parts that move around or are load-bearing. It is simple to shape and does not wear out easily; thus, engineers use it, and it does not create noise when used in machines. Nylon parts are mostly used in automotive systems, industrial machinery, and electronics.
Gears and Bearings
Nylon gears are employed in situations where it is necessary to have smooth and quiet operation. They are usually used in conveyors, printers, and light machinery. They require little lubrication and last longer before wearing out. Nylon bearings also reduce the friction of rotating components and guard the shafts against damage, which has aided machines in operating as efficiently as possible over a period of years.
Bushings and Spacers
Nylon bushings are useful in reducing vibrations and friction in moving parts. They are commonly put into pumps, motors, and hinges. They also guard the parts of metals against direct contact. Nylon fillers maintain a constant distance between components in assemblies. They serve to keep the components in line and to eliminate any noise and vibration during the load.
Fasteners and Washers
Where the metal cannot be used, nylon fasteners are employed. They are not corrosive or conductive, and this can be applied in electronics and maritime devices. The tightening of the parts evenly distributes the load among the nylon washers. They also protect sub-surface and inhibit instability in assemblies under pressure.
Rollers and Wheels
Conveyor systems and packaging machines usually entail a roller and a wheel made of nylon. Their movements are defiant. They maintain constant movement without leaving any trace on the surface. The nylon wheels can support weight without being deformed and remain dependable at varying temperatures.
Electrical Insulators
Nylon finds application in electrical components because it’s a non-conductor. It is effective in switches, wire connectors, and housings. It is moisture and heat-resistant, which maintains the high level of performance in hostile conditions.
Automotive Components
Nylon is used to make cars lighter, and at the same time, it remains tough. It finds application in the clips, braces, and engine covers. It is also resistant to oil, fuel, and vibration, making it a good product to be used in the engine as well as the interior. These parts enhance productivity and the lifespan of modern-day cars.
Summary
This article has covered the practical role of nylon in engineering and manufacturing. It explained how nylon parts manage friction, absorb vibration, and hold tight tolerances in demanding systems. You saw how gears, bushings, and rollers made from nylon improve motion control and reduce mechanical wear. Its chemical resistance and dimensional stability make it a preferred choice for precision components in both mechanical and electrical assemblies.
FastPreci provides CNC machining services designed for technical materials like nylon. Our engineers understand how to control heat buildup, minimize tool wear, and achieve tight surface finishes during nylon machining. With 3-axis to 5-axis equipment and ISO-certified processes, we provide consistent accuracy from prototype to production. Contact FastPreci today to discuss your nylon machining needs and get a fast, detailed quote for your project.
