Solid particle contaminants introduced into lubrication systems is one of the leading causes of accelerated failure in mechanical equipment. Contaminants often enter into a lubrication system when fluids are being addes or checked. The importance of pouring through clean funnels and using clean cloths to wipe down dipsticks is frequently overlooked in general maintenance and oil changing procedures. Particle contaminants introduced into a system breakdown into smaller particles and get suspended in oil. These particles can scour and gouge surfaces, make the oil more viscous and block oil passages.

• The average diameter of a grain of table salt is around 100 microns.
• The average diameter of a human hair is around 100 microns.
• The most harmful contamination in a lubrication system is normally below the 40 micron range.
• Fine tolerance clearances between moving parts usually range between 5 to 20 microns.
• Small contaminant particles suspended in the oil can lodge themselves between tight clearances.
• Contaminants often enter a lubrication system when fluid is being added or checked.
• Contaminants come from dirty funnels or dirty cloths used to wipe down the dipstick.
• Contaminants in a funnel cannot be evaluated by visual inspection.