www.ipesearch.com BEARINGS, SEALS & LUBES 31
Do your lubricants make the
The quality of the lubrication products
used on bearings has an impact on
overall equipment lifespan. Look for
products with high performance in
international standard tests.
The ASTM B 117 Salt Spray Test is one of
the longest established corrosion tests.
A sample is placed on steel panels,
placed inside a fog of 5% salt solution.
The sample is checked for signs of
corrosion at regular intervals. The
longer the sample withstands those
signs of corrosion, the better the grease
is at protecting the components.
The ASTM D 6138 EMCOR Test –
another well-established testing
method – considers the corrosion of a
dynamic bearing in a wet environment.
Bearings are loaded with grease and
mounted in plummer blocks with 10ml
of water added to each side. The
machine runs for eight hours followed
by 16 hours’ standing time. This is
repeated three times before the
bearings are left to stand for four days.
The test runs for a week before the
bearing is removed from the machine
and disassembled. The interior race is
then examined for corrosion and given
a score: 0 equals no corrosion and 5
denotes severe corrosion levels.
Another rating to look out for is the
ASTM D 1264 Water Washout Test.
During this test, a 38°C or 79°C jet of
water is aimed at a shielded 6204
bearing filled with test grease for an
hour. The percentage weight of
grease washed out of the bearing is
calculated. In this test, the lower the
weight the better. It means less
grease was washed out during testing
and therefore has remained in the
bearing, where it is needed to
lubricate and protect the bearing.
When selecting bearing greases for
use in wet environments, look for
products that carry these
certifications, and manufacturers that
offer these high levels of performance
testing as standard. This will give
confidence that the lubricants used
are of the highest quality and will
outperform inferior products in
Another factor to be aware of is the
need for food safe products in some
applications and production
When dealing with waste water, a
standard industrial grease will do the
job. However, in the food or clean
industries, a bearing grease that has
been registered in the most relevant
category with NSF International (e.g. H1
for lubricants with incidental food
contact) is required. This precautionary
measure mitigates against grease
dripping from the bearing onto the
production line. Look out for greases
with NSF registrations and ISO 21469
quality standard marks for peace of
mind with regard to food safety.
When dealing with drinking water,
another level of safety assurance is
required in the form of Water
Regulations Advisory Scheme (WRAS)
certification. A WRAS certificate
demonstrates that the grease complies
with the high standards set out by the
water industry regulators.
Check it out
Regular maintenance checks can help
spot early warning signs of corrosion
and provide opportunities to act before
bearing performance is compromised.
Without them, operators could be left
with expensive repairs and unplanned
downtime. Making regular corrosion
checks part of ongoing maintenance
regimes is time well spent.
Bearings in industrial machinery where
corrosion is a risk during operation, be
it from frequent washdown, humidity
or water ingress, require specific
maintenance to ensure continued high
performance and maximum lifespan.
Without regular proactive
maintenance, operators face the
bigger cost of bearing failure and
downtime through unplanned
maintenance – a cost many businesses
simply cannot afford.
For more information:
Tel: 0113 232 2600
help spot early