I lost a key of my safe

To order replacement keys, for small chests and files, you will need to know the key numbers which can be found right around where the key goes in. It should be a stamped number, letters, or both located around the keyhole. For Personal, Home and Home/Office Safes, you will need the model number and serial number. I think that the most economical place to buy keys is from www.SentrySafeShop.com. You can do a search for "lost keys" and it will give you a screen where you can enter your model number and key number. They key ordering screen is: www.sentrysafeshop.com/Keys-Sentry-Safe-Replacement-Keys-p/keys.htm
They just need 1.)Model # and 2.)Serial or Key #.)

In Summary:
For Small Chests or Files: A lock reference number is required. It will be a letter, a number, a letter and number, or "blank" (no letter or number), engraved/located on the silver cylinder of the lock. These are model numbers 0500, 1100, 1170, etc...

For Personal, Home and Home/Office Safes: (model numbers will begin with: S0, S3, S4, S5; I0, I3, I4, I5; A3, A4, A5; J3, J4, J5; L0, L3, ,CS,CSW,DA,DS,KS,KSW,MS,MSW,OA,OS,and SC): Indicate your model number and the safe serial number found on the front right-hand side of the door, between the hinges.
Here is the direct link to the key replacement screen: http://www.sentrysafeshop.com/Keys-Sentry-Safe-Replacement-Keys-p/keys.htm
For Small Chests or Files: (Model numbers will begin with 0500, 1100, 1110, 1150, 1160, 1170, 1710, 1900, 1950, 1970, 1200, 1210, 1250, 2100, 2180, 2275, 2460, 6000, 6720, 7150, A3750, A5781, A5865, F2300, F3300, H2100, H2300, H3100, H2300, H3300, H4100, H4300, HD2100, HD4100, KDS-1, KS2100, KS4100, U2101, WD2, WD4, ESB-3, etc... ): A lock reference number is required. It will be a letter, a number, a letter and number, or "blank" (no letter or number), engraved/located on the silver cylinder of the lock (right around the hole where the key goes in at).

For Personal, Home and Home/Office Safes:(Model numbers will begin with: S0 (S0310, S0400, S0407, S0408, S0409, S0410), S3 (S3300, S3310, S3401, S3410, S3417, S3421, S3460, S3467, S3470, S3710, S3807, S3870, S3877, S3910), S4, S5; I0, I3, I4, I5; A3, A4, A5; J3, J4, J5; L0, L3, CS, CSW (CSW3460), DA (DA3831, DA3930), DS (DS3410, DS3431, DSW5781), KSW, MS, MSW, OA (OA3810, OA3821, OA5848), OS (OS0407, OS0410, OS0810, OS3407, OS3421, OS3470), SC, and X (X031, X075, X105, X125)): Indicate your model number and the safe serial number found on the front right-hand side of the door, between the hinges. Keys Sentry Safe Replacement Keys Keys Sentry Safe Replacement Keys

Drill the cylinder out. These safes are to keep fire out, not burglars. Or take it to a locksmith. They can easily open it.