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Shore hardness

Shore hardness rates how soft or hard a material feels. Learn how Shore A and Shore D work and why printed parts can feel softer.

3 min read · Updated October 11, 2026 · Numbers update live from our materials database.

What it means in practice

Shore hardness measures how far a spring-loaded pin can press into a surface. It is the standard way to describe how soft a flexible material feels, from a gel-like pad to a hard wheel.

Key takeaways

  • Shore hardness describes how soft or firm a surface feels, on a 0 to 100 scale.
  • Shore A suits soft rubbers; Shore D suits hard rubbers and plastics.
  • A and D are different tests with no exact conversion, so compare within one scale.
  • Printed parts feel softer than their rating; infill lets you tune the feel.
Standard resins (Shore D)80typical · range 70–87 · 43 materials
Engineering filaments (Shore D)71typical · range 66.7–77 · 12 materials
TPU powders (Shore A)88typical · range 86–93 · 8 materials

It is the key number for:

  • Seals and gaskets, which must be soft enough to conform but firm enough not to extrude.
  • Grips, handles and wearables, where feel matters.
  • Shock absorbers, feet and bumpers.
  • Wheels, rollers and drive belts.

Good to know

Rigid resins and filaments are often given a Shore D value too. For them it says more about surface hardness and scratch resistance than about flexibility.

How it’s measured

A handheld or stand-mounted durometer presses an indenter into the material. The reading runs from 0 (the pin sinks fully) to 100 (no sinking at all).

  • Standards: ASTM D2240 and ISO 48-4 (which replaced ISO 7619-1).
  • Scales: Shore A uses a blunt tip and a lighter spring, for soft rubbers. Shore D uses a sharp tip and a stronger spring, for hard rubbers and plastics. There are other scales, such as 00 for very soft gels.
  • Units: none. The value is written with its scale, for example 85A or 60D.
  • Specimen: at least about 6 mm thick, often stacked from thinner pieces.

Shore A

Blunt tip, lighter spring. For soft rubbers such as TPU and flexible resins. Written like 85A.

Shore D

Sharp tip, stronger spring. For hard rubbers and rigid plastics. Written like 60D.

How to read and compare it

  • Same scale only. A and D are different tests. The scales overlap around the top of A and the bottom of D, but there is no exact conversion. See Shore A vs Shore D.
  • Reading time. Soft materials relax under the pin, so a reading taken after 15 seconds is lower than an instant one. Good sheets state the time.
  • Printed parts feel softer. The rating is for solid material. Lower infill, thin walls and pattern choice make a TPU part feel far softer than its Shore value. You can tune feel with infill.
  • Temperature. Elastomers firm up in the cold and soften when warm.
  • Not a strength value. Two materials with the same hardness can differ a lot in tear strength and stretch.

In our catalog

Shore values are stored as text with their scale, so we don’t show a single numeric range. Instead, here is how many materials carry our flexible badge, which marks rubber-like materials and anything measured on the Shore A scale:

  • All flexible materials: 69
  • Flexible filaments: 25
  • Flexible resins: 35
  • Flexible powders: 8

Watch out

Each chart below uses a single Shore scale. Never read a value on one chart against a value on the other.

Shore A hardness of TPU powders by process
  1. SLS 486–90
  2. MJF 488–93

Bar = lowest to highest, dot = median. 8 materials, live from our database.


Shore D hardness of rigid filaments by type
  1. Standard 552–76
  2. Engineering 1266.7–77
  3. Specialty 346–81

Bar = lowest to highest, dot = median. 20 materials, live from our database.

Open any material to see its Shore value and scale. For how flexible materials stretch, compare their elongation at break:

  • Flexible materials: 15–2,000 % (median 280 %, 63 materials)

For design tips, see flexible parts.

See all flexible materials 69 materials