ISO 4406:1999
The code is constructed from the combination of 3 numbers selected from the following table.
The first number represents the number of particles larger than 4 micron.
The second number represents the number of particles larger than 6 micron.
The third number represents the number of particles larger than 14 micron.
For example, 19/17/14 means
2500 to 5000 particles greater than 4 micron
640 to 1300 particles greater than 6 micron
80 to 160 particles greater than 14 micron

Range CodeParticles per milliliter
More thanUp to / Including
23 40000 80000
22 20000 40000
21 10000 20000
20 5000 10000
19 2500 5000
18 1300 2500
17 640 1300
16 320 640
15 160 320
14 80 160
13 40 80
12 20 40
11 10 20
10 5 10
9 2.5 5
8 1.3 2.5
7 0.64 1.3
6 0.32 0.64


NAS 1638
ClassMaximum Number of Particles per 100 ml
5 - 15 microns15 - 25 microns25 - 50 microns50 - 100 microns>100 microns
00 125 22 4 1 0
0 250 44 8 2 0
1 500 89 16 3 1
2 1000 178 32 6 1
3 2000 356 63 11 2
4 4000 712 126 22 4
5 8000 1425 253 45 8
6 16000 2850 506 90 16
7 32000 5700 1012 180 32
8 64000 11400 2025 360 64
9 128000 22800 4050 720 128
10 256000 45600 8100 1440 256
11 512000 91200 16200 2880 512
12 1024000 182400 32400 5760 1024


Viscosity



Babbitt Metal
White-metal alloy as a lining for bearings was first proposed in 1839 by Issac Babbitt
who recommended a mixture composed of about
tin, Sn
50 parts
89.28 %
antimony, Sb
5 parts
8.93 %
copper, Cu
1 part
1.79 %


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