Introduction
This manual provides essential instructions for the proper setup, operation, and maintenance of your Mesa Safe MBF Series Combination Lock Safe. Designed for robust protection against both burglary and fire, this safe is constructed with all-steel and features a U.L. Listed Group 2 combination lock. Please read this manual thoroughly before using your safe to ensure optimal security and longevity.
Key features include:
- Solid steel construction for enhanced durability.
- U.L. Listed Group 2 Combination Lock for reliable security.
- Fire-resistant lining and heat-activated seal, factory rated for 2 hours at 350°F.
- 2-story impact rating, factory tested for durability.
- Three massive 1-inch diameter solid steel locking bolts and heavy-duty hinges.
- Adjustable and removable interior shelves.
Safety Information
Always prioritize safety when handling and operating your safe. Failure to follow these guidelines may result in injury or damage to the safe or its contents.
- Heavy Object: The safe is extremely heavy. Exercise extreme caution during unpacking, moving, and installation. Always use appropriate lifting equipment and seek assistance from multiple individuals.
- Anchoring: For maximum security and to prevent tipping, especially if the door is open, the safe must be securely anchored to the floor.
- Children: Do not allow children to play with or around the safe. Never leave the safe door open and unattended.
- Lock Mechanism: Do not attempt to force the lock or handle. If you experience difficulty, refer to the troubleshooting section or contact customer support.
- Fire Safety: While the safe offers fire protection, it is not fireproof. Store heat-sensitive items with caution and consider additional protective measures if necessary.
Setup
1. Unpacking
Carefully remove all packaging materials from the safe. Inspect the safe for any signs of damage that may have occurred during shipping. Report any damage to your dealer immediately.

Figure 1: Front view of the Mesa Safe MBF Series Combination Lock Safe in its closed position.
2. Placement
Choose a suitable location for your safe. Consider factors such as accessibility, security, and proximity to a structural support for anchoring. Ensure the floor can support the safe's weight.
3. Anchoring the Safe
For optimal security and stability, it is highly recommended to anchor your safe to the floor. The MBF Series safe includes 4 pre-drilled anchor holes and an anchor kit for this purpose.
- Open the safe door and remove any interior shelving to access the pre-drilled holes in the bottom of the safe.
- Position the safe in its desired location.
- Mark the floor through the pre-drilled holes.
- Move the safe aside and drill pilot holes into the floor at the marked locations, using a drill bit appropriate for your flooring material (concrete, wood, etc.).
- Reposition the safe over the drilled holes.
- Insert the anchor bolts from the provided kit through the holes in the safe and into the floor.
- Tighten the anchor bolts securely. Do not overtighten.

Figure 2: Interior view of the safe with shelves, illustrating access to potential anchoring points on the base.
4. Installing Shelves
The safe comes with adjustable and removable shelves. Position them according to your storage needs. Ensure shelves are securely seated on their supports.
Operating the Combination Lock
Your Mesa Safe MBF Series features a U.L. Listed Group 2 combination lock. The factory-set combination is typically provided on a separate tag or document included with your safe. Keep this combination in a secure location, separate from the safe.
Opening the Safe (Example Combination: 50-25-50)
To open your safe, follow these steps precisely:
- Clear the Dial: Turn the dial four (4) or more full turns to the left (counter-clockwise) to clear any previous attempts.
- First Number (50): Turn the dial to the left (counter-clockwise), passing the first number (50) three (3) times, and stopping on the first number (50) on the fourth time.
- Second Number (25): Turn the dial to the right (clockwise), passing the second number (25) two (2) times, and stopping on the second number (25) on the third time.
- Third Number (50): Turn the dial to the left (counter-clockwise), passing the third number (50) one (1) time, and stopping on the third number (50) on the second time.
- Open Handle: Once the final number is reached, turn the safe handle clockwise to retract the locking bolts.
- Open Door: Pull the door open.
Note: Always use your specific factory combination. The example combination above is for instructional purposes only.

Figure 3: The safe door open, revealing the combination dial and the robust locking bolts.
Closing and Securing the Safe
- Close the safe door firmly.
- Turn the safe handle counter-clockwise to extend the locking bolts. Ensure the handle is fully turned and the bolts are engaged.
- Spin the combination dial several turns in either direction to scramble the combination and prevent unauthorized access.
Maintenance
Regular maintenance ensures the long-term performance and security of your Mesa Safe.
- Cleaning: Wipe the exterior of the safe with a soft, damp cloth. Avoid abrasive cleaners or solvents that could damage the finish.
- Lock Mechanism: The combination lock is a precision instrument. NEVER lubricate the lock mechanism or the dial. Lubricants can attract dust and debris, leading to malfunction.
- Hinges: The heavy-duty hinges are designed for durability and typically do not require lubrication. If you notice any stiffness, contact customer support.
- Heat-Activated Seal: Inspect the heat-activated seal around the door frame periodically for any signs of damage or degradation. This seal is crucial for fire protection.
Troubleshooting
If you encounter issues with your safe, refer to the following common problems and solutions:
- Difficulty Opening the Safe:
- Ensure you are using the correct combination and following the dialing procedure precisely.
- Verify that you are stopping on the correct numbers and turning the dial in the correct direction for each number.
- Make sure the dial is cleared by turning it several times counter-clockwise before starting the combination.
- If the safe has been moved or subjected to impact, the internal mechanism might be slightly misaligned. Try the combination again carefully.
- Handle Does Not Turn After Dialing Combination:
- Confirm the combination was dialed accurately. A slight over-turn or under-turn can prevent the lock from disengaging.
- Apply gentle pressure to the door while turning the handle, in case there is slight pressure on the bolts.
- Safe Door Does Not Close Properly:
- Check for any obstructions inside the safe or around the door frame that might be preventing it from closing fully.
- Ensure the shelves are properly installed and not interfering with the door mechanism.
If these troubleshooting steps do not resolve your issue, please contact Mesa Safe Co. customer support for assistance.
Specifications
| Feature | Detail |
|---|---|
| Model | MBF3820C |
| Lock Type | U.L. Listed Group 2 Combination Lock |
| Material | Alloy Steel, Metal |
| Special Feature | Fire Resistant (2 hours at 350°F, tested up to 1830°F) |
| Impact Rating | 2-story impact rated |
| Mounting Type | Freestanding (with 4 pre-drilled anchor holes) |
| Exterior Dimensions (LxWxH) | 22 x 22 x 40 inches |
| Package Weight | 310 Pounds |
| Door Thickness | 4-1/2 inches (with fire-resistant material) |
| Body Thickness | 1-3/4 inches (with fire-resistant lining) |
| Locking Bolts | Three 1-inch diameter solid steel |
| Interior | Fully upholstered, adjustable/removable shelves |
| Water Resistance Level | Not Water Resistant |
| UPC | 817932010591 |
Warranty Information
The Mesa Safe MBF Series Combination Lock Safe is backed by a limited lifetime warranty. For specific details regarding warranty coverage, terms, and conditions, please refer to the warranty card included with your purchase or visit the official Mesa Safe Co. website.
Customer Support
Should you require further assistance, have questions about your safe, or need to report a warranty claim, please contact Mesa Safe Co. customer support. Contact information can typically be found on the manufacturer's official website or in the documentation provided with your safe.
For the most up-to-date support resources, please visit the official Mesa Safe Co. website: www.mesasafe.com