Key to Prefix Numbers
Block Width (mm)
Number
The Concrete Masonry Association
of Australia has established a
national metric coding for all units
manufactured by its members. This
accounts for approximately 90% of
all concrete masonry manufactured
within Australia. The coding system
standardises the dimensional
descriptions of masonry units. This
allows a designer to specify any unit
by number and to be certain that it
can be identified correctly anywhere
within this country.
40
76
90
110
140
190
290
50
75
10
12
15
20
30
Key to Suffix Numbers
Block Length
Block
height
Block
Full
3⁄4
(mm)
type
(390 mm)
(290 mm)
1⁄2
(190 mm)
1⁄4
(90 mm)
190
190
90
90
03
33
73
85
04
34
74
86
Hollow
Solid*
Hollow
Solid*
01
31
71
83
02
32
72
84
* Some manufacturers use an alternative method of
designating solid units.
Note:
With the exception of 50 and 75, the
prefix numbers are derived by adding
10 mm for the mortar joint width to the
unit width and dividing by 10.
30
28
30
40
13
5
15
2
28
28
13
5
15
2
15
2
40
40
25
30
90
40
6
15
7 2
15
7 2
25
190
39
39
0
0
28
190
0
19
29
39
0
20.01 BLOCK
39
0
10.01 BLOCK
0
0
14
Figure 1 Coding System
Suffix identifies
unit type and
configuration
(190-mm high,
hollow, full length)
0
21
190
90
Prefix identifies
nominal wall
thickness
(200 mm)
40
30
25
190
25
15
2
5
th
ng
Le
40
Height
CODE NUMBER 20.01 (for example)
0
13
25
th
id
Remember, when working with cement and concrete/mortar or manufactured or prefabricated concrete products, ALWAYS follow the manufacturer's
instructions and seek advice about working safely with the products from the manufacturer, your nearest WorkCover Authority or Worksafe Australia.
NATIONAL METRIC
CODING SYSTEM
W
Disclaimer: The Concrete Masonry Association of Australia Limited is a non-profit organisation sponsored by the concrete masonry industry in
Australia to provide information on the many uses of concrete masonry products. Since the information provided is intended for general guidance
only and in no way replaces the service of professional consultants on particular projects, no liability can be accepted by the Association for its use.
Concrete Masonry Association Australia
PO Box 370,
P: 02 8448 5500
Artarmon
F: 02 9411 3801
NSW 1570
www.cmaa.com.au
15.01 BLOCK
30.01 BLOCK
Figure 2 Typical Dimensions and Code Number of Some Standard Full-size Blocks
DATA SHEET 1
National Metric Coding System
SEPTEMBER 2000