This aggregate classification system uses a
HM-925 Thickness Gauge for determining flakiness
index and a metal HM-926 Length Gauge for
determining elongation index. Aggregate is separated
into seven sieve fractions from 63—6.3mm,
and each fraction is evaluated separately.

HM-925 Thickness Gauge

has seven labeled
slots for rapid hand trying of particles from each
of the seven sieve cuts. The mass of all flaky
particles as percent of the sample is the flakiness
index. Thickness Gauge is enameled sheet metal
with clearly marked sieve fraction ranges for each
slot. Est. Ship Wt.: 3lb (1kg).

HM-926 Length Gauge

has six labeled openings
between pairs of metal pins for measuring length
of particle from each of the six sieve cuts below
50mm. The mass of all elongated particles as
percent of the sample is the elongation index. The
Length Gauge has stainless pins set in a brushed
aluminum base stamped with sieve fraction ranges
between pins. Est. Ship Wt.: 3lb (1kg).

Test aggregates must be sieved using sieves with
openings of 63, 50, 37.5, 28, 20, 14, 10, and 6.3mm.
These are available separately (listed elsewhere)
as 200mm diameter brass frame sieves with
stainless steel cloth as International Test Sieves.