If one correlates the various pencil hardnesses
with their Martens Hardness, the limitations of the method become even more obvious.
To determine the relative hardnesses
of minerals, hardness scales were developed, initially with the idea of defining equal hardness intervals between points on the scales.
Eventually, the values of both Janka and Brinell cross-section hardnesses
for those cross sections whose MCs deviated from 12 percent was converted to 12 percent MC by the following equation:
This study examined five different PUF samples formulated for specific hardnesses
that represent a range of cushion hardness used globally (ref.
The low-hardness test is used for testing samples greater than or equal to 6 mm thick and hardnesses
in the 10-35 IRHD range.
The Evergreen Series is currently available in Shore A hardnesses
of 10, 20, 30, 40, 50 and 60.
range between 20 Shore A and 50 Shore A, depending on the function of the roller.
High-resilience, high-rebound TPUs for injection molded and extruded products come in hardnesses
of 70 Shore A to 55 D.
Aluminum bronze alloys in a range of hardnesses
and tensile/yield strengths for mechanical wear applications in guide, leader and ejector pins, bushings, slides, gibs, wear plates and unscrewing mold components.
Widely used in athletic shoes, Pebax comes in hardnesses
from 25 to 70 A.