Shore 95A, 87A, 83A — what the numbers mean, which brands to trust, and exactly which TPU to use for phone cases, gaskets, RC tires, and more.
Best All-Around
Polymaker PolyFlex TPU95 — Shore 95A, works on any direct drive, $25/kg
Best Budget
eSUN eTPU-95A — reliable, $18/kg, good for beginners
Softest / Professional
NinjaTek NinjaFlex 85A — industry standard for gaskets and wearables
Shore hardness measures how soft or firm a material is. For TPU filaments, you'll see Shore A scale (softer materials) or Shore D (harder, semi-rigid). The lower the number, the softer the material.
| Shore Rating | Feel | Printability | Best For | Example |
|---|---|---|---|---|
| 83–87A | Very soft (gel-like) | ⚠️ Hard — needs DD, slow speed | Gaskets, wearables, extreme flex | NinjaFlex 85A |
| 92–95A | Firm rubber (car tire feel) | ✅ Good on direct drive | Phone cases, RC tires, dampers | PolyFlex TPU95 |
| 98A | Hard rubber (boot sole) | ✅✅ Easiest to print | Semi-rigid snap-fits, hinges | Polymaker TPU98A |
| 40D (~94A) | Semi-rigid | ✅ Reliable | Structural flex parts, clips | Fiberflex 40D |
✅ Excellent diameter consistency, low stringing, prints reliably at 220-230°C. Works on most printers.
⚠️ Limited color options vs budget brands
Best for: All-around best for functional parts
✅ Designed for Bambu AMS. Excellent quality, easy to tune. Good for all printers.
⚠️ Pricier than budget options; AMS use requires separate TPU path
Best for: Bambu Lab printers, high-quality prints
✅ Budget-friendly, good quality, widely available. Reliable on direct drive printers.
⚠️ Slightly more stringing than premium brands; tolerances ±0.05mm
Best for: Best value for beginners
✅ Industry benchmark for soft TPU. Used in professional/medical applications. Very durable.
⚠️ Expensive. Slow (15-20mm/s). Requires direct drive.
Best for: Gaskets, medical wearables, extreme flex
✅ Cheapest reliable TPU. Fine for prototypes and non-critical parts.
⚠️ More diameter variation. Needs tuning.
Best for: Prototypes, learning TPU settings
✅ European brand. High-quality, semi-rigid. Good for snap-fits needing flex.
⚠️ Less common, harder to find outside EU
Best for: Semi-rigid functional parts, EU market
Phone cases & covers
Firm enough to hold shape, absorbs drops. TPU is the standard material for commercial phone cases.
RC car tires
95A for hard terrain/speed. 87A for grip and off-road. Lower shore = more grip, less speed.
Cable organizers & clips
Snaps around cables without cracking. Flexible enough to install/remove easily.
Shock absorbers / vibration dampers
Lower durometer absorbs vibration better. Used in drone landing gear, printer anti-vibration feet.
Gaskets & seals
Very soft TPU compresses to seal gaps. Resistant to oils and many chemicals.
Grip handles & knobs
Over-printed on rigid PLA or printed solid. Shore 87A gives the most comfortable grip feel.
Flexible hinges
Living hinges in TPU flex thousands of times. More durable than Nylon for small-scale hinges.
Wearables / bracelets
Soft enough for skin contact. Choose food-safe TPU for items touching skin long-term.
| Setting | Shore 95A | Shore 87A | Shore 83–85A |
|---|---|---|---|
| Nozzle Temp | 220–235°C | 220–230°C | 215–230°C |
| Bed Temp | 40–50°C | 30–45°C | 30–40°C |
| Print Speed | 25–40 mm/s | 15–25 mm/s | 10–20 mm/s |
| Retraction | 0–2mm (DD only) | 0–1mm (DD only) | 0mm (no retraction) |
| Cooling Fan | 30–50% | 30–50% | 30–50% |
| Extruder | DD recommended | DD required | DD required |
| Infill | 15–40% | 15–30% | 10–20% |
Bowden extruder warning: TPU softer than Shore 98A will buckle inside Bowden PTFE tubes. Direct drive is required for Shore 95A and below. Upgrading to a Creality Sprite extruder (~$35) solves this for most Ender 3 models.
Slow down — always
TPU speed is limited by how fast the extruder can compress the flexible filament. Overshooting speed = underextrusion. Start at 25mm/s and tune up.
Near-zero retraction on direct drive
Retraction pulls flexible filament back but also stretches it unpredictably. 0–1.5mm at 25mm/s is enough to prevent stringing without causing jams.
Disable combing / travel avoidance
Combing moves the nozzle over infill to avoid crossing perimeters. On TPU this causes inconsistent extrusion — disable it and accept minor stringing instead.
Keep a consistent feed path
Any friction point between the spool and extruder can cause TPU to buckle. Use a filament guide or run directly from spool to extruder with no sharp bends.
Use flexible PEI or Garolite bed
TPU sticks well to PEI but can be hard to remove. A flexible magnetic PEI sheet (like Bambu or Prusa) lets you flex the bed to pop prints off without damage.