Which filament to choose for spare parts: PLA, PETG, ASA, nylon or CF
A 3D printer can quickly produce a broken bracket, cover, guide or spacer. But the same part made from the wrong material may warp near a motor, crack on impact or degrade in contact with oil. The most common mistake is printing everything in PLA because it is the simplest. In this article we compare the most common filaments and explain how to choose a material for a functional spare part.
First answer 4 questions
- What is the temperature where the part will be used? Near a motor, a heater, in direct sunlight or in a closed cabinet, the temperature is considerably higher than in a room.
- What is the load? Does the part only hold something, or is it constantly bent, rubbed or struck?
- What is the environment? Outdoors (UV rays, cold, humidity), oil, lubricants, cleaning chemicals.
- What can your printer do? Maximum nozzle temperature, whether it has an enclosed chamber, and whether the nozzle is hardened steel.
The answers immediately rule out some materials. For example, if the printer is open and has a brass nozzle, ABS, ASA and carbon fibre filaments will be difficult for it.
Filament comparison
The table shows general material properties. Nozzle temperatures are taken from the data of the manufacturers of the filaments we sell; the specific manufacturer's recommendations always take precedence.
| Material | Strengths | Weaknesses | Nozzle temperature* |
|---|---|---|---|
| PLA | Easiest to print, precise, shrinks little | Softens already at about 55 °C, more brittle, does not like prolonged UV and heat | 190–230 °C |
| PETG | Tougher and more resistant to impact and chemicals than PLA, layers bond well | Can 'string', slightly less precise | 220–250 °C |
| ABS / ASA | More heat-resistant; ASA also withstands UV, suitable for outdoor use | Shrinks, needs an enclosed chamber, emits fumes when printing – ventilation required | 230–265 °C |
| Nylon (PA12) | Wear- and impact-resistant, low friction – gears, bushings, sliders | Absorbs moisture, must be dried before printing | 240–270 °C |
| With carbon fibre (CF) | Stiffer, holds dimensions well, matte surface | Abrasive – requires a hardened steel or tungsten carbide nozzle; less flexible | Depends on the base (PLA-CF 190–220 °C, PA12-CF 250–290 °C) |
| TPU | Flexible, rubber-like – gaskets, dampers, protective covers | Slow printing, best with a direct extruder | 210–230 °C |
* According to the manufacturers' data for the filaments in our catalogue. Ranges differ between manufacturers.
When to choose which
PLA – for templates, prototypes and indoor use
Suitable for measuring templates, mounting jigs, indoor cable holders, and prototypes before printing in a more expensive material. Not suitable for parts that get hot – e.g. next to a motor, in an electrical cabinet in summer or in a car in the sun. Example: Polymaker PLA, black, 1 kg.
PETG – a versatile functional material
A good first choice for most spare parts: brackets, protective caps, cable channels, cabinet accessories. Prints without an enclosed chamber, so it suits most printers. Example: Polymaker PolyLite PETG, white, 1 kg.
ASA – outdoors and in warmer environments
If the part will be outdoors (a sensor bracket, a cover on a building, agricultural machinery), choose ASA – it resists UV and weather. Its properties are similar to ABS, but it ages more slowly in sunlight. Both need an enclosed chamber so larger parts don't warp. Example: Polymaker PolyLite ASA, white, 1 kg.
Nylon – for moving and wearing parts
Gears, bushings, sliders, chain guides – nylon usually performs best here thanks to its wear resistance and low friction. The key is dry filament: nylon absorbs moisture from the air, and damp filament prints weak, porous parts. Example: Devil Design PA12, natural, 800 g.
CF filaments – when stiffness is needed
Carbon fibre makes the part stiffer and more dimensionally stable – suitable for brackets that must not bend, frames and jigs. But a hardened steel or tungsten carbide nozzle is required – brass wears out quickly from the fibre. Examples: Polymaker Fiberon PETG-rCF and Rosa3D PA12 + 15 % CF. More about this in our separate article on carbon fibre filaments.
Common mistakes
- PLA where it's warm. The part looks fine, but after a few weeks in a warm place it deforms.
- Damp filament. Especially nylon, but also PETG – bubbles, crackling while printing, weak layers. Keep filaments sealed with a desiccant.
- Wrong layer orientation. A 3D printed part is weakest between layers. Orient the part so the main load does not 'pull apart' the layers.
- Too few walls. For functional parts, the number of walls is often more important than the infill percentage.
- Safety-critical parts. We do not recommend 3D printing parts for guards, lifting or braking mechanisms – choose the original. When printing is suitable, we wrote in the article '3D printed spare parts in industry'.
In brief: how to choose
- Indoors, away from heat and impact → PLA.
- Versatile functional part → PETG.
- Outdoors, in the sun, warmer → ASA.
- Friction and wear → nylon (PA).
- Need stiffness and precision → CF filament (with a hardened nozzle).
- Flexible, rubber-like part → TPU.
How to find them on inteq.lt
All filaments – in the section Filaments: PLA, PETG, ASA, ABS, nylon, CF, TPU and special types (ESD, flame-retardant V0) from Polymaker, Rosa3D, Devil Design and Gembird. Looking for a specific filament by manufacturer code? Enter it in the search by manufacturer code or photograph the spool label with the 📷 button – we will show the same filament or an equivalent. Not sure which material will suit your part? Write to us via užklausos formą – tell us where the part will be used and which printer you have.
