Used in leaking faucet repair. Grind down the seat of the valve within a faucet, so the rubber makes a tight fit and keeps water out.
Home Repair Resource Center
http://hrrc-ch.org/toollibrary/
2520 Noble Rd.http://hrrc-ch.org/toollibrary/
Cleveland Heights, OH, 44121
USA
(216) 381-6100