Save money on production without compromising strength in your design
Wall thickness is the distance between the outer and inner surface of your 3D print. Many mistakenly view the wall as a purely visual shell, but technically it functions as a beam that supports the entire structure.
Your decision on wall thickness directly dictates your price. When you increase the thickness, the machine requires more material and significantly more 3D print time. Our price calculator analyzes the volume of the material contained in your file. Doubling the wall thickness from 1 mm to 2 mm often doubles the material consumption in the shell, which drives the price up.
You must therefore find the balance. A wall that is too thin creates a risk of failure and useless parts, while a wall that is too thick is a waste of money.
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How do you calculate the optimal wall thickness to save money?
You achieve the best economy by hitting the point where the part is strong enough for its function without paying for superfluous plastic.
Data shows that a wall thickness of 2 mm often constitutes the economic “sweet spot” for functional parts. Here, you get a solid structure that can withstand handling and assembly. If you go up to 4 mm or 5 mm, you are paying for extreme strength that is rarely necessary for ordinary purposes unless you are building heavy enclosures.
Use the principle of selective thickness. Instead of making the entire part thick and expensive, you should keep the general thickness low. A level of 1.2 mm to 1.6 mm is often sufficient for the body of the part itself. You should only reinforce the specific areas exposed to direct mechanical stress. This reduces your total 3D print price considerably.
How much strength do you actually gain by increasing wall thickness?
We often see customers over-dimensioning their designs out of fear that the parts will break. To put the numbers into perspective, physical compression tests of a 40 mm cube show clear results for the relationship between strength and thickness.
- A wall of only 1 mm can withstand approximately 306 Newtons. This corresponds to the weight of a large dog of about 31 kg. The part holds the weight, but it will begin to bulge under pressure, which is called buckling.
- A wall of 2 mm delivers a huge jump in strength. It resists up to 1760 Newtons. This corresponds to placing an ATV (approx. 175 kg) on top of the part. For most customers, this strength level is more than enough for functional prototypes and end products.
- A wall of 4 mm managed 4300 Newtons in the test, which corresponds to the weight of a piano.
- A 5 mm wall managed over 6000 Newtons, corresponding to a filled hot tub.
You should therefore ask yourself if your 3D print actually needs to carry a hot tub. If not, save the money and stay closer to 2 mm. Taking action on these small adjustments is the key to a better bottom line.
What significance does 3D printer technology have for your wall thickness?
Your chosen technology determines the minimum requirements for your design.
An FDM 3D printer, which melts plastic filament, depends on the nozzle size. The nozzle is typically 0.4 mm wide. To achieve a stable wall, you should design with a multiple of this. We recommend a minimum of 1.2 mm, which corresponds to three perimeters, to ensure water-tightness and stability.
An SLA 3D printer, which cures liquid resin, is more precise. Here, the material cures chemically using light. This means you can often go down to 0.8 mm or even 0.6 mm in certain resin types without the part losing its shape. If your goal is the absolute lowest price on small parts, SLA can allow for thinner walls than FDM.
Here is an overview of recommended minimum measurements to ensure a good 3D print price and quality:
| Technology | Minimum wall thickness | Recommended “safe” wall thickness |
| FDM (PLA/PETG) | 0.8 mm | 1.2 – 1.6 mm |
| SLA (Resin) | 0.6 mm | 0.8 – 1.0 mm |
| SLS (Nylon) | 0.8 mm | 1.0 – 1.2 mm |
How do you avoid invisible costs from walls that are too thin?
The most expensive cost in 3D print is a print that fails and must be remade. If you save too aggressively on wall thickness, you risk buckling. Under load, a wall that is too thin—for example, 1 mm on a large part—will behave like a beam that bends to the side. Even if the plastic does not break, the part loses its structural stability and thus its function.
Another problem is unsupported walls. If you design a thin wall that sticks up high without support, it will vibrate during the 3D print process. This results in a poor surface finish and inaccurate geometry. You pay for a print you cannot use. Therefore, never go below the minimum recommendations just to save a few INR on the material.
How do you check and adjust wall thickness in your design software?
You should use your software actively to lower the price. An effective method for this is local reinforcement using STEP files. This is especially important if you use threaded inserts, which require extra wall thickness to melt into place securely.
Follow this procedure to optimize the price without losing strength:
- Initial Design: Start by designing your part with a thin general wall thickness.
- Local Reinforcement: Create separate cylinders around your screw holes in your CAD program. These cylinders should have the necessary thickness, for example, 2 mm of solid plastic around the hole.
- Embedding Technique: Make the cylinder slightly shorter than the part itself. If your part is 10 mm high, make the cylinder 8 mm high and remove 2 mm from the front edge. Place the cylinder inside the wall. This prevents visible rings on the outside of your print, as the transition is hidden inside the model.
- Export Format: Export the entire design as a STEP file rather than an STL file. When you upload or slice, the software now recognizes the individual parts as separate objects. This gives you the option to set the general model to few wall lines, which is cheap, while forcing the cylinders to be massive and strong.
Avoid making perforations or small holes around the main hole to create strength. Tests show that this creates porous surfaces and stress points that weaken the part instead of strengthening it.
What is the minimum wall thickness for 3D print?
The recommended minimum thickness depends on the technology you choose. For an FDM 3D printer, you should design with at least 1.2 mm to ensure stability in the layers. If you use an SLA 3D printer with resin, you can often go down to 0.8 mm. If you go below this, you risk failure in your 3D print.
How strong is a 3D print with a 2 mm wall?
A 3D print with a 2 mm wall is surprisingly strong and can withstand pressure up to 1760 Newtons. This corresponds to the weight of an ATV placed on top of the part. For most functional parts, this is more than enough, and additional thickness is therefore often a waste of money.
Is a thicker wall always better for my 3D print?
No, a thicker wall is not necessarily an advantage for your end product. Although it increases strength, it also increases the price significantly due to extra material and extended 3D print time. Often, it is better to use a standard wall of 1.2–2 mm and increase the internal infill to provide stability.
What is the difference between wall thickness and infill?
Wall thickness is the solid outer shell, while infill is the internal structure that supports the part. Think of the wall as the car’s bodywork and the infill as the supporting chassis. You save money by keeping the wall thin and letting the infill carry the structure, as infill is typically printed faster than solid outer walls. To take action and achieve the best results, you must master the balance between these two settings.
Does FDM and SLA require different wall thicknesses?
Yes, the two technologies have different technical requirements for the design. An FDM 3D printer uses a nozzle (typically 0.4 mm) and requires thicker walls to effectively bind the layers together. An SLA 3D printer is more precise and can handle finer details and thinner walls without losing its structural integrity.
How do I create strong screw holes without thick walls?
You should use the technique of selective thickness using STEP files. Design a local reinforcement around the hole—for example, a 2 mm cylinder—but keep the rest of the part thin. This ensures that your threaded inserts are securely seated without you paying to make your entire 3D print massive and expensive.
How to ensure the lowest unit price today
To ensure the best price at 3D actions, you should follow three main rules in your design work:
- Aim for 2 mm wall thickness for functional parts. This provides strength equivalent to supporting an ATV, which covers the vast majority of needs for mechanical components.
- Utilize internal infill for strength. Your wall does not need to be solid. Let the wall be the shell and let the infill function as the load-bearing lattice.
- Use STEP files for selective thickness. Keep your primary wall thickness down to 1.2 mm to save 3D print time, and embed hidden reinforcements only where you need to mount screws or brackets.
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