Material Comparison

TPU Shore Hardness Compared

85A, 90A, 95A, 98A - what the numbers mean, how they print, and which one to buy for your project.

Last updated: March 2026

For a full overview of TPU and other flexible filaments, see our TPU material guide:

TPU Filament Guide
The Shore A scale explained

Shore A measures how hard a flexible material is. The test is simple: a standardized needle is pressed into the material under a fixed load, and the depth of penetration determines the number. Lower number = softer and more flexible. Higher number = harder and more rigid.

For context: a rubber band is roughly 25A. A pencil eraser is about 40A. A car tire tread is around 70A. Shoe soles range from 50A-80A. The TPU filaments you can buy for 3D printing typically range from 85A to 98A - they are all on the harder end of the Shore A scale.

The key thing to understand: the Shore A scale is not linear in how it feels. The difference between 85A and 90A is very noticeable. The difference between 95A and 98A is subtle. And once you pass 98A, you are basically printing a rigid material that happens to have some impact resistance.

TPU hardness at a glance
Hardness Feels like Print difficulty Extruder Max speed Use cases
85A Silicone, gel insole Hard Direct drive only 15-20 mm/s Soft grips, watch bands, gaskets, vibration dampeners
90A Gummy bear, soft shoe sole Moderate Direct drive only 20-30 mm/s Phone cases, flexible hinges, soft bumpers
95A Shoe sole, firm rubber Easy (for TPU) Direct drive (Bowden possible) 25-40 mm/s Wheels, belt tensioners, seals, protective cases
98A Hard rubber, hockey puck Easiest Direct drive or Bowden 30-50 mm/s Tough wheels, impact-resistant housings, stiff but not brittle parts
When to use
85A - 90A (Soft)

This is the range where TPU actually feels flexible. 85A bends easily in your hand like thick silicone. 90A has noticeable give, like a soft phone case. These are the hardness levels you want for gaskets, vibration dampeners, soft-touch grips, and flexible hinges that need to bend hundreds of times without fatigue.

The trade-off is printability. At 85A, the filament is soft enough to compress and buckle between the extruder gears and the hotend. You need a direct drive extruder with a constrained filament path[1], very slow speeds (15-20 mm/s), minimal or zero retraction, and patience. Stringing is basically guaranteed - plan to clean up your prints.

Popular brands at this range: NinjaTek NinjaFlex (85A), Sainsmart (85A), Polymaker PolyFlex (90A).

Community tip: If you are buying 85A for the first time, print a simple 20mm calibration cube first. If it comes out clean, your setup can handle it. If it jams immediately, check your filament path for any gaps where the soft filament can escape.
When to use
95A (Standard)

95A is the default TPU for a reason. It is flexible enough to be obviously rubbery (it bends, compresses, and bounces back), but stiff enough to feed through most direct drive extruders without constant jams. If you have never printed TPU before, start here. Most of the TPU tutorials and profiles you find online are tuned for 95A.

95A works for the vast majority of flexible print applications: wheels for robots or RC cars, belt tensioners, phone cases, cable strain reliefs, protective bumpers, and seals. It gives you real flexibility with manageable print difficulty.

Some users have printed 95A successfully on Bowden tube setups (Ender 3, etc.) at very slow speeds (15-20 mm/s), but it is not reliable. Direct drive is strongly recommended.

Community tip: Disable retraction entirely on your first 95A print. Only add retraction (0.5-1.5mm, slow speed) if stringing is unbearable. Too much retraction causes jams - TPU compresses rather than retracting cleanly.
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When to use
98A (Firm)

98A is barely flexible. It feels like hard rubber - think hockey puck or a hard-soled work boot. You can bend a thin-walled 98A print if you try, but it is not going to flex back and forth like a phone case. What 98A gives you is impact resistance: parts that absorb hits instead of shattering like PLA or PETG would.

98A is the easiest TPU to print. It feeds through Bowden tubes (at reasonable speeds), has less stringing than softer TPU, and can print at 30-50 mm/s without major issues. If you need a part that survives drops and impacts rather than one that actually flexes, 98A is the most practical choice.

Ideal for: drone frames, impact-resistant housings, tool grips, wheels that need to be tough but not soft, and parts that get dropped or crashed regularly.

Community tip: Many people buy 98A TPU expecting flexible phone cases and are disappointed. If you want visible flex in a thin-walled print, go 95A or softer. 98A is for impact absorption, not flexibility.
The community verdict

Buy 95A unless you have a specific reason not to. It is the goldilocks hardness: flexible enough for real applications, stiff enough to print reliably on a direct drive machine. If you need something softer, go to 90A. If you just need impact resistance without real flex, go to 98A.

Do not buy 85A as your first TPU. Start with 95A, get your settings dialed in, then work downward in hardness as your confidence and printer setup allow. The softer the TPU, the more you need to fight your printer to make it work. And always dry your TPU before printing - it absorbs moisture fast and prints terribly when wet.

Frequently Asked Questions

Can I print 85A TPU on a Bowden tube printer?
Almost certainly not reliably. 85A TPU is soft enough to buckle and jam in a Bowden tube, even at very slow speeds. The long, unguided filament path gives the flexible filament too much room to compress and kink. Direct drive is mandatory for 85A. Even some direct drive setups struggle - you want a constrained filament path with minimal gap between the drive gears and the melt zone.
What is the most common TPU hardness?
95A is the industry standard. When a brand sells "TPU" without specifying hardness, it is almost always 95A. This is because 95A hits the sweet spot of being flexible enough for most applications while still being printable on most direct drive printers. Brands like Overture, eSUN, and Elegoo all default to 95A for their standard TPU offerings.
What speed should I print TPU at?
It depends on hardness. 95A-98A can typically print at 25-40 mm/s on a direct drive printer. 90A should be slowed to 20-30 mm/s. 85A often needs 15-20 mm/s or even slower. Retraction should be minimal (0.5-2mm) or disabled entirely, as TPU compresses rather than retracts cleanly. Print speed is the single biggest factor in successful TPU printing - going too fast causes jams, not just quality issues.
Is 98A TPU actually flexible?
Barely. 98A TPU feels like hard rubber - it has some give if you squeeze it hard, but it does not flex freely like a phone case or gasket would. Many people buy 98A expecting rubbery flexibility and are disappointed. If you want noticeable flex, go with 95A or softer. 98A is better described as "impact absorbing" rather than "flexible."
Do I need to dry TPU before printing?
Yes. TPU is hygroscopic and absorbs moisture from the air within hours. Wet TPU produces stringing, bubbling, popping sounds during extrusion, and rough surface finish. Dry at 50-55 °C for 4-6 hours before printing, and ideally print from a dry box. See our filament storage guide for drying tips. This applies to all hardness levels.
What is the difference between TPU and TPE?
TPE (thermoplastic elastomer) is the broad category. TPU (thermoplastic polyurethane) is a specific type of TPE. In practice, when filament brands sell "TPE" it is usually softer (often 80A-85A) and harder to print than their "TPU" offerings. If a product just says "TPE" without a Shore rating, expect it to be quite soft and challenging to print.

References

  1. NinjaTek NinjaFlex (85A) Printing Guide. https://ninjatek.com/ninjaflex/
  2. Prusa Knowledge Base - Flexible Materials (TPU/TPE). https://help.prusa3d.com/article/flexible-materials_2057