Door Lockset

The UL ANSI Grade 2 Fireproof Zinc Alloy Knob Lock is positioned as a reliable and cost-effective locking solution for light to medium-duty commercial and residential applications requiring certified fire protection. Manufactured with a durable zinc alloy body and reinforced internal components, it delivers stable performance and long-lasting usability under daily operation. Certified to ANSI Grade 2 standards, it is designed to withstand frequent use, while its UL listing with a 3-hour fire rating ensures dependable performance on fire-rated door assemblies. Engineered for smooth knob rotation and secure latch engagement, this lock is well suited for wooden or metal doors in apartments, offices, schools, hotels, and public buildings where balanced security, fire compliance, and practical functionality are essential.

Technical Specifications

Product Images and Videos

Product Features & Advantages

• ANSI Grade 2 Certification: The DDLK012 knob lock meets ANSI Grade 2 standards, tested to exceed 400,000 usage cycles. This ensures reliable performance for high-traffic residential and light commercial entrances such as apartment buildings, offices, and public facilities. The Grade 2 rating confirms strong mechanical durability, impact resistance, and consistent locking performance, reducing long-term maintenance and replacement costs.
• UL 3-Hour Fire Resistance: Certified with a 3-hour UL fire rating, the lock maintains structural integrity and latch functionality during fire exposure. This level of fire protection supports life-safety compliance in residential buildings, offices, healthcare facilities, and hospitality environments. In emergency situations, the fire-resistant construction helps maintain secure compartmentalization while preserving safe exit routes.
• Zinc Alloy & Stainless Steel Construction: The exterior knob is constructed from high-quality zinc alloy, offering corrosion resistance and finish durability for daily use. The internal latch bolt is made of stainless steel, providing enhanced anti-pry strength and long-term structural stability. This material combination ensures both aesthetic appeal and dependable security performance across diverse environments.
• Removable Core Cylinder: Equipped with a 5-pin or 6-pin removable core cylinder compatible with the Schlage “C” keyway, the lock allows convenient rekeying without replacing the entire unit. This feature is particularly valuable for property managers, landlords, and facility operators who require flexible access control for multi-unit residences or commercial spaces.
• Versatile Door Compatibility: Designed to fit doors 1-3/8" to 2" thick, the lock features an adjustable backset of 2-3/4" or 2-3/8", accommodating standard door preparations. Its flexibility makes it suitable for homes, offices, schools, healthcare facilities, and hospitality projects without requiring specialized modifications.
• Easy Installation & Maintenance: The removable rosette design with screw-thread fixing simplifies installation and future servicing. Contractors can install or disassemble components efficiently, while maintenance teams benefit from straightforward access during inspection or rekeying.

Installation Steps

1. Prepare Door & Tools: Confirm the door thickness is between 1-3/8" and 2". Prepare necessary tools such as a drill, screwdriver, and measuring tape to ensure accurate measurements and proper alignment before installation.
2. Drill Door Prep Holes: Drill a 2-1/8" cross bore and 1" edge bore, ensuring correct positioning for latch alignment. Prepare the latch face area (1-1/8" x 2-1/4") so the faceplate sits flush with the door edge.
3. Install Latch Assembly: Insert the stainless steel latch into the edge bore and align the faceplate evenly with the door edge. Secure it firmly with screws to ensure smooth bolt extension and retraction.
4. Attach Knob & Rosette: Position the zinc alloy knob and removable rosette over the cross bore. Fasten securely using the screw-thread system, ensuring stable mounting and correct alignment with the latch mechanism.
5. Install Strike Plate: Mount the 2-1/4" full lip strike plate onto the door frame, aligning precisely with the latch bolt. Secure tightly to ensure full engagement and reliable locking performance.
6. Test Operation & Integration: Turn the knob several times to verify smooth operation and proper latch engagement. If paired with door hinges or door closers, confirm synchronized and unobstructed door movement.

Application Scenarios

The DDLK012 Fireproof Knob Lock is engineered for environments requiring dependable security, fire compliance, and long-term durability.

In residential entry doors, it provides ANSI Grade 2 mechanical strength combined with 3-hour fire resistance, enhancing household safety while maintaining aesthetic flexibility. In commercial office entrances, its durable zinc alloy construction withstands frequent daily use, integrating seamlessly with door closers and hinges for smooth and controlled door operation.

Within healthcare facilities, the UL-listed fire resistance supports emergency preparedness and code compliance, while the removable core cylinder simplifies access management for authorized personnel. In educational institutions, its high cycle durability ensures reliable performance despite heavy student traffic.

For hospitality venues such as hotels and motels, the lock offers both security and rekeying convenience, allowing property managers to efficiently manage guest room access while maintaining consistent hardware styling.

Certifications and Compliance

The DDLK012 Knob Lock meets rigorous industry standards for security, durability, and fire safety:

• ANSI Grade 2 Certification: Tested to exceed 400,000 operating cycles, validating durability and mechanical reliability for residential and light commercial applications.
• UL Listing: Certified for 3-hour fire resistance, ensuring safety performance in fire-rated door assemblies.
• ISO 9001 Quality System: Manufactured within D&D’s ISO 9001-certified quality management framework, ensuring strict oversight from raw material inspection through final product testing.

Customization Options

D&D offers OEM/ODM customization for the DDLK012 knob lock to meet project-specific needs:

• Finish Customization: Available in a wide range of finishes such as polished chrome, satin nickel, oil-rubbed bronze, or custom coatings to match architectural aesthetics and door hardware themes.
• Cylinder Customization: Supports master key systems and alternative keyway configurations for enhanced access control in multi-unit or commercial properties.
• Material Upgrades: Optional higher-grade zinc alloy or stainless steel variants are available for coastal, high-humidity, or industrial environments requiring increased corrosion resistance.
• Branding: Custom logos, engravings, and private-label packaging options are available for property developers, distributors, and OEM/ODM projects.

Production Process & Quality Control

1. Material Sourcing: High-grade zinc alloy and stainless steel materials are carefully selected and tested for corrosion resistance, strength, and compliance with ANSI and UL standards.
2. Precision Machining: Advanced CNC machining ensures accurate shaping of knobs, rosettes, cylinders, and latch components, maintaining tight tolerances for consistent performance.
3. Finishing & Coating: Surface treatments undergo strict adhesion and durability testing to ensure long-lasting finish quality under daily use conditions.
4. Assembly: Each lock is assembled by integrating the knob, rosette, cylinder, and latch mechanism, followed by functional verification to ensure smooth operation and secure locking.
5. Quality Inspection: Every unit is subjected to operational cycle testing, structural checks, and detailed visual inspection to meet ANSI Grade 2 and UL performance requirements.
6. Certification Testing: Random sampling verifies compliance with ANSI, UL, and BHMA standards to maintain consistent safety and durability benchmarks.
7. Packaging: Products are packaged in protective white, color, or customized cartons with clear labeling to prevent transit damage and support efficient project logistics.