Filament is the fuel of FDM 3D printers. But, as we all know, not all filament is the same.
Different filaments vary in their base material, brand, mechanical properties, color, and also their diameter. While most people print with 1.75-mm filament, this isn’t the only filament diameter.
There’s also the 2.85-mm filament diameter, which is more common on higher-end 3D printers and offers some different extrusion properties compared to 1.75-mm filament.
So what’s the difference between 1.75 and 2.85-mm filament?
Well, besides 1.75-mm filament being more popular, it’s also less expensive and more widely available compared to 2.85-mm filament. And, when it comes to printing performance, 1.75-mm filament actually yields more detailed prints than 2.85-mm filament.
But, if you’re printing with flexible filament and want a stiffer filament (to avoid extrusion issues) or you want a filament with a lower diameter tolerance, then 2.85-mm filament might be for you.
And, the two different filament diameters aren’t interchangeable, meaning you can only print 1.75-mm filament on a printer that’s meant for printing 1.75-mm filament. If you want to use the other filament diameter, you would have to change the extruder assembly, PTFE tube, hot end, and a bunch of slicer settings to make your printer compatible.
Want to learn more about the differences between 1.75 and 2.85-mm filament, as well as each of their advantages and disadvantages?
Then, just keep reading!
Table of Contents
- What Does Filament Diameter Mean?
- Why Does Filament Diameter Matter?
- History Between Diameters
- Advantages of 1.75 mm Filament
- Advantages of 2.85 mm Filament
- Difference Between 1.75 mm & 2.85 mm: Which One is Better for You?
- Is There a Difference Between 2.85 & 3.00 mm Filament?
- Can You Use 1.75 mm Filament in a 2.85 mm 3D Printer?
What Does Filament Diameter Mean?
The first thing to understand is that the diameter of the filament refers to the width of the filament. Furthermore, if you took a caliper to some 1.75-mm filament and measured the width of the filament between the caliper’s jaws, it should read about 1.75 mm. And, if you did the same to 2.85-mm filament, it would be approximately 2.85 mm.
Of course, both 1.75 and 2.85-mm filament have some variation in their diameters, and this is usually recorded and specified by the manufacturer as the “tolerance” of the filament. It can vary between +/- 0.01 to +/- 0.1 mm.
Why Does Filament Diameter Matter?
Filament diameter is an important factor to consider when choosing a filament because it can affect the quality and accuracy of the final printed object.
In general, a filament with a lower diameter will result in more detailed and precise 3D prints because the 3D printer can lay down melted filament in smaller areas. On the other hand, a larger diameter filament will produce a coarser and less-detailed print, but the filament is less bendable, which solves issues that I’ll cover later.
Additionally, what filament diameter you can choose depends on the 3D printer you have. For example, if you have a budget-3D printer, such as the Creality Ender 3 or basically any other sub-$1,000 machine, then you probably need to use 1.75-mm diameter filament as this is what the printer’s extruder, hot end, and other components have been made for.
But, if you have a machine meant for 2.85-mm filament, which is usually more focused on professional-grade printing, like the LulzBot Taz Workhorse or Ultimaker S3, then you must use a 2.85-mm filament.
History Between Diameters
Before we get into the two different filament diameters, you might be wondering how we ended up with these two seemingly-arbitrary filament diameters, anyways.
Well, the main reason we have 1.75 and 2.85-mm filaments is that when FDM 3D printing was first being developed, there weren’t a lot of string-like plastic strands that people could use.
As such, 3D printing enthusiasts turned to ABS welding rods, which were short, string-like plastic strands used for niche welding purposes. These filament-like “rods” measured about 2.85-mm in diameter and were the first FDM filaments to be 3D printed.
However, as 3D printing got more popular, people started to switch to Bowden extruder configurations instead of the original direct drive extruder setups. But there weren’t many options for the PTFE (Teflon) tube required for Bowden extruders. And, once again, the pioneers of FDM 3D printing had to turn to alternative products that weren’t meant for 3D printing.
The two diameters of PTFE (Teflon) tubes from existing manufacturers at the time were 2.0 and 3.0 mm. This led to the adoption of 1.75-mm and 2.85-mm filaments, as these diameters could fit inside 2.0 and 3.0-mm PTFE tubes.
Finally, as FDM 3D printing became more popular, new manufacturers started to enter the space, making products specific to 3D printers. And, as people realized 1.75-mm filament offered more useful benefits than the original 2.85-mm filaments, this smaller diameter started to become more widely used, and that’s why it’s the most popular 3D printing filament diameter today.
And, with that history lesson out of the way, let’s dive into the two filament diameters and their benefits!
Advantages of 1.75 mm Filament
If you have a 3D printer, chances are you probably use 1.75-mm filament. 1.75 mm is, by far, the most popular filament diameter for 3D printing, especially on budget 3D printers. And, today, there are many benefits of using 1.75-mm filament.
Price & Availability
First off, because 1.75-mm filament is the universally adopted filament diameter for FDM 3D printing, you have the most options when it comes to picking a spool. Moreover, there are thousands more 1.75-mm diameter filaments than 2.85-mm filaments. Because of this, you have many more options regarding color, surface texture (e.g. silk, regular, matte), and special properties (e.g. conductive, FDA-approved) for 1.75-mm filaments than with any other diameter.
On a similar note, 1.75-mm filaments, because there’s a much larger supply of them, typically cost a few bucks less, per spool, than 2.85-mm filaments.
Improved Printing Precision
But, price and availability aren’t the only benefits of 1.75-mm filament. In fact, the whole reason the 3D printing community ever made the switch from 2.85-mm filament to 1.75 mm is that the smaller filament diameter offers a higher level of printing precision.
Furthermore, because the filament diameter is smaller, the extruder can more precisely control the flow of filament. That’s because less plastic is being pushed out of the nozzle for every 1-mm extrusion of 1.75-mm filament than with 2.85-mm filament. And, if we crunch the numbers, we can see that 1.75-mm filament can be printed with over 60% more extruder control (assuming the hardware is the same).
So, how does this impact printing? Well, because of the improved extrusion control, you can achieve better retractions with 1.75-mm filament than with 2.85-mm filament. This will result in much less stringing on your 3D prints.
Higher Print Speed
The other major benefit of going with 1.75-mm filament is that you can print much faster than if you were using a larger-diameter filament. Even though 2.85-mm filament is more plastic per 1-mm strand, it requires considerably more force to push through a PTFE tube and nozzle. Because extruders can more easily push 1.75-mm filament, you can achieve a higher maximum volumetric flow rate, which impacts how fast you can print the material.
And, if that wasn’t enough to convince you to use 1.75-mm filament, it’s also less likely to snap during printing compared to thicker filament diameters. As such, you don’t have to worry as much about the filament strand breaking when it goes from your spool to your extruder.
Advantages of 2.85 mm Filament
With all of the advantages of 1.75-mm filament in mind, you might be thinking, “what does 2.85-mm filament have that could possibly make it better?”. And, you’ve got a good point!
2.85-mm filament is objectively the worst filament diameter for most people. Not all people, though!
Stronger Filament Strand
The first major advantage of 2.85-mm filament is that the actual filament strand is stronger than 1.75-mm filament. Of course, that’s because a 2.85-mm filament strand is larger and, thus, stiffer than a 1.75-mm filament strand, so it will take more to snap it in half.
While this might not seem like much of an advantage, it’s a useful property for printing flexible filaments, like TPU or TPE. That’s because flexible filaments, especially in small diameters, tend to bend a lot inside the extruder which can cause the extruder to jam (e.g. if the filament wraps around the drive gear).
Using 2.85-mm filament is a great way to avoid this issue because your 3D printed parts will be just as flexible but extruder jams are much less likely to occur due to the stiffness of the thicker filament.
Improved Diameter Tolerance
Another benefit of using 2.85-mm filament is that these filaments typically have a better diameter tolerance than 1.75-mm filaments. Moreover, most filaments, no matter their diameter, have a tolerance of +/- 0.05 mm, meaning the filament strand’s diameter might vary by plus or minus 0.05 mm.
The reason this makes 2.85-mm filament more accurate is that a 0.05 mm is about 2.9% for 1.75-mm filaments, but only 1.8% for 2.85-mm filaments. As such, small variations in a filament’s diameter are less likely to cause extrusion issues on 2.85-mm filaments than with 1.75-mm filaments.
Of course, this isn’t that much of an advantage, because filament manufacturing technology has become good enough to keep diameter variations to a minimum. But, still, it’s something to note!
Difference Between 1.75 mm & 2.85 mm: Which One is Better for You?
At the end of the day, 1.75-mm filament is probably the better option for you, especially if you’re not printing flexible filaments.
The relatively-smaller filament diameter offers improved printing precision over 2.85-mm filament, which will make stringing and other extrusion issues on your prints less significant. Additionally, you can print 1.75-mm filament a good bit faster than you can 2.85-mm filament. And, 1.75-mm filaments are not only less expensive than 2.85-mm filaments, but also come in more options (e.g. color, special properties).
However, there might be a few of you interested in printing 2.85-mm filament. First off, if you already have a 3D printer meant for 2.85-mm filament, like a LulzBot Taz Workhorse, then, obviously, it makes sense to purchase a 2.85-mm filament. But, also if you’re getting into 3D printing and want to print a lot of flexible materials, 2.85-mm might be the better option as it’s less likely to jam your extruder or snap on your spool.
Is There a Difference Between 2.85 & 3.00 mm Filament?
The terms “2.85-mm filament” and “3.00-mm filament” are synonymous, and both refer to filament measuring 2.85 mm in diameter. The reason some people and manufacturers call this filament 3.00-mm filament, though, is because it fits in a 3.00-mm diameter tube.
So, if you have a printer that works with 2.85-mm filament, then feel free to purchase any 3D printing filament that’s listed as either “2.85 mm” or “3.00 mm”.
Can You Use 1.75 mm Filament in a 2.85 mm 3D Printer?
No! Or, at least, not without a lot of hardware changes to the 3D printer.
A printer meant for 1.75-mm filament won’t work with 2.85-mm filament and a printer meant for 2.85-mm filament won’t take 1.75-mm filament.
Of course, 1.75-mm filament can technically fit inside a printer meant for 2.85-mm filament because the smaller diameter won’t clog the extruder or hot end assemblies. However, it won’t print to a reasonable extent because the extruder won’t have enough tension on the inserted filament to properly push it through the PTFE tube or out the nozzle.
And, on this note, the PTFE tube on printers meant for 2.85-mm filament is 1.00 mm larger than the one used on 1.75-mm printers. As such, the filament won’t fit snugly inside the PTFE tube as it’s supposed to, meaning, even if the filament does print, there will be a ton of stringing on any print.
But, without changing the extruder assembly, PTFE tubing, PTFE tube couplers, and many components of the hot end, then you won’t be able to achieve even a decent-quality print if you use 1.75-mm filament on a printer meant for 2.85-mm filament.
While 2.85-mm filament was necessary for the original development of FDM 3D printing, it’s now become an outdated and archaic diameter choice. Today, you’re probably better off going with a 1.75-mm filament for a plethora of reasons.
On top of being more popular and universally-accepted, 1.75-mm filament also allows for a better printing precision. Moreover, you can expect less stringing and other extrusion issues on prints made with this smaller filament diameter. And, you can print 1.75-mm filament much faster than you can 2.85-mm filament.
Of course, 2.85-mm filament isn’t all bad. Some 3D printers still exclusively accept 2.85-mm filament, which is the main reason why this filament diameter is even around today. But 2.85-mm filament is also great for flexible materials because the larger diameter makes the filament stiffer, which reduces the likelihood of extruder jams when printing the material.
But, at the end of the day, what filament diameter you use will probably be based on what diameter your existing 3D printer works with (likely 1.75 mm).