TPU Shore Hardness Explained (85A, 95A and Beyond)

TPU is sold by shore hardness — numbers like 85A or 95A — and that single figure tells you both how flexible the part will be and how hard the filament is to print. Choosing the right grade is often more important than any slicer setting.

Shore hardness measures how much a material resists indentation. TPU uses the Shore A scale: lower numbers are softer and more rubbery, higher numbers are firmer and more like a hard eraser.

• Shore 85A — very soft and stretchy (squishy grips, soft gaskets). Hardest to print.
• Shore 90A — a middle ground: flexible but easier to feed.
• Shore 95A — semi-rigid, bends but springs back firmly (phone cases, tyres, functional flexible parts). Easiest to print and the most common.

There is a direct trade-off: the softer the TPU, the more it compresses in the extruder and the more prone it is to buckling and jams. 95A is the recommended starting grade for anyone new to flexibles — it prints close to a normal filament while still bending usefully. Save 85A for when a part genuinely needs to be squishy, and ideally print it on a direct-drive machine at very low speed (see TPU speed & retraction).

Match the grade to the job:

• Phone cases, tool grips, RC tyres: 95A — firm flex, easy printing.
• Gaskets, seals, vibration dampers: 90–95A depending on squish needed.
• Soft squishy parts, wearables: 85A — only if your extruder can feed it.

When in doubt, choose the firmest grade that still bends enough for the job — it will print more reliably every time.

Reviewed 2026-08-18. Starting points and general guidance — always calibrate for your filament brand and machine.