Hi all,

Small Parts Inc. stocks carbide, synthetic ruby (red) and sapphire (clear)
balls that could probably
replace (and very likely enhance the pivot) of your steel ball bearings in
your seismometer pivots.

The corundum sizes range from 1/64" up to 1/8" @ $3.45 up to $4.00 each.
You can buy in
quanity somewhat cheaper.  The sphericity (roundness) listed is 0.000025".

http://www.smallparts.com/products/descriptions/brb.cfm
http://www.smallparts.com/products/descriptions/BSP.cfm

The tungsten carbide balls range from 1/16" up to 1/2" @ $3.25 up to $16.80
each.  They
have metric sizes also.  The sphericity listed is 0.0006"...quite abit less
round than the corundum.

http://www.smallparts.com/products/descriptions/btc.CFM

The "big bite" of it all is their shipping/handling costs ~ $14.00 (USA)
irregardless of the small weight.
Their FedEx "2 day" shipping could be up to 4-5 days.  Ground shipping ~ 7
to 10 or more days.

Take care, Meredith
Hi all,

Small Parts Inc. stocks carbide, synthetic ruby (red) and sapphire (clear) balls that could probably
replace (and very likely enhance the pivot) of your steel ball bearings in your seismometer pivots.  


The corundum sizes range from 1/64" up to 1/8" @ $3.45 up to $4.00 each.  You can buy in

quanity somewhat cheaper.  The sphericity (roundness) listed is 0.000025".

http://www.smallparts.com/products/descriptions/brb.cfm

http://www.smallparts.com/products/descriptions/BSP.cfm


The tungsten carbide balls range from 1/16" up to 1/2" @ $3.25 up to $16.80 each.  They
have metric sizes also.  The sphericity listed is 0.0006"...quite abit less round than the corundum.

http://www.smallparts.com/products/descriptions/btc.CFM



The "big bite" of it all is their shipping/handling costs ~ $14.00 (USA) irregardless of the small weight.
Their FedEx "2 day" shipping could be up to 4-5 days.  Ground shipping ~ 7 to 10 or more days.


Take care, Meredith