Here's the USMint sheet on damaged coins
http://www.usmint.gov/downloads/faqs/mutilated.pdf
QUESTIONS AND ANSWERS ABOUT UNCURRENT AND MUTILATED COINS
1) What is the difference between Uncurrent and Mutilated coins?
UNCURRENT: U.S. coins which are merely worn or reduced in weight by natural abrasion, yet are readily and clearly recognizable and machine countable, are classified as Uncurrent Coins.
MUTILATED: All coins that are bent, broken, corroded, not whole, melted together and not machine countable, are classified as Mutilated Coins.
2) Where do I redeem Uncurrent coins?
Uncurrent coins are redeemable at Federal Reserve Banks and their branches at face value. (This includes silver coins).
3) Where do I redeem Mutilated coins?
Mutilated coins are redeemable at:
United States Mint ATTN: Mutilated Coin Redemption Section P.O. Box 400 for Post Office shipments only
151 N. Independence Mall East Philadelphia, PA 19106
You may mail them through the U.S. Post Office, Federal Express, UPS, etc. You can also deliver in person to the loading dock located between Race and Arch streets on 4th street. Receiving hours are 7:00AM to 1:30PM, Monday through Friday.
ALL PERSONS DELIVERING COINS TO THE U. S. MINT, MUST FIRST SCHEDULE A DROP OFF DATE AND BE CLEARED BY THE UNITED STATES MINT POLICE AT LEAST 24 HOURS IN ADVANCE. PLEASE CALL (215) 408-0203 FOR MORE INFORMATION.
4) Are there any mutilated coins that the U.S. Mint will not redeem?
The following will not be redeemed by the U.S. Mint:
a) Fused material unrecognizable as U.S. currency.
b) Foreign coins.
c) Counterfeit coins and slugs.
d) Altered coins, changed to pass as another denomination. Coins or lumps of coins, which contain lead, solder or other substances, which would make them unsuitable for use as coinage metal.
e) Precious coins (gold or silver).
5) Note: There is a minimum of 1LB or .45KG per denomination or separated alloy that can be accepted for redemption. Any underweight coin will not be processed for redemption and all shipping expenses and risk involved with the mutilated coins shipped to the United States Mint will be incurred by the shipper.
6) Do I have to separate the coins, pennies from nickels, etc?
If you do not separate the coins by denomination, you will only receive 20% of what you send in for redemption because the sorting will have to be done by the U.S. Mint.
7) How will I be paid for these mutilated coins?
You will receive a check for your coins or direct deposit to your bank account if you complete a SF-3881, ACH Vendor/Miscellaneous payment enrollment form.
Denomination Category:
Rate per Kg.
/ Lbs.
a) Cents, both copper and copper zinc.
$3.21
$1.46
b) Nickels
$9.99
$4.54
c) Clad coins(dimes, quarters,halves)
$44.09
$20.00
d) Dollar(Susan b.Anthony,Golden Dollar)
$123.46
$56.00
REMEMBER THE U.S. MINT ONLY REDEEMS COINS!

Paper Currency is redeemed at:
Department of the Treasury Bureau of Engraving and Printing OCS, BEPA, Room 344 P.O. Box 37048 Washington, D.C. 20013
9) How long do I have to wait for payment?
It is estimated that you will receive payment within 6 to 8 weeks from the time the coins arrive at the U.S. Mint.
10) Can I call the U.S. Mint to check on my coin shipment?
Primary number to call is (215) 408-0203 Secondary number is (215) 408-0201