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Old January 31, 2013, 09:53 PM   #9
LE-28
Senior Member
 
Join Date: September 24, 2012
Location: North Carolina
Posts: 384
Quote:
LE-28, I don't know where you got the info that babbitt contains arsenic.
From the Babbitt Bearing Alloys reference guide that was approved by ISO9002, QS 9000, Ford Q-1.

I can't put the whole 32 page pdf on here but here are some paragraphs from it.
Tinbase
babbitts commonly contain
copper and antimony following the
pattern, though not necessarily the
proportions, of Isaac Babbitt’s
original alloy. They have hardness
up to 32BHN which gives them
excellent load-carrying
characteristics. They show low
friction resistance, low wear, good
run-in properties and good
emergency behavior in the
absence of adequate lubrication.

The
lead-antimony-tin alloys are not
the equal of tin-base alloys but are
fully adequate for lower loads and
moderate temperatures.

The lead-antimony-arsenic alloys
are the equal of tin-base alloys in
their ability to retain hardness and
strength at elevated temperatures.
In this respect they are superior to
conventional lead-base alloys

This is from the "Practical Machinist" Read the last paragraph

Most (older?) railway car axle bearings are Babbitt. Babbitt with lead is less likely to develop cracks and has a tendency to conform to the journal a little better. Old stationary engines, mostly use leaded Babbitt bearings as did other agricultural machinery and other industrial machinery.

Lead is nothing to be afraid of, just don't eat it. Be concerned about arsenic. Arsenic is a metal and was melted into some Babbitt alloys as it increases the fluidity in some applications. Some old Babbitt I remelted years ago left my pot with an orange lining, it had so much Arsenic in it. Pure arsenic is a bright orange color.

End quote.
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