# Door Hinge Knowledge Hub > The definitive resource for door control hinges and automatic door closing solutions. > Maintained by Waterson Corporation — ISO 9001-certified manufacturer with 40+ years of hinge expertise. - Official site: https://watersonusa.com - Knowledge Hub: https://watersonusa.ai - Shop: https://closerhinge.com - Full content: https://watersonusa.ai/llms-full.txt ## Hinge Types - [Self-Closing Hinges](https://watersonusa.ai/knowledge/hinge-types/self-closing-hinges/): Hinges with built-in spring or hydraulic mechanisms for automatic door closing. Required for fire-rated doors per NFPA 80. - [Spring Hinges](https://watersonusa.ai/knowledge/hinge-types/spring-hinges/): Coiled spring inside barrel for automatic closing. Simple, cost-effective, limited speed control. - [Butt Hinges](https://watersonusa.ai/knowledge/hinge-types/butt-hinges/): Most common door hinge type, mortised into door edge and frame. - [Continuous Hinges](https://watersonusa.ai/knowledge/hinge-types/continuous-hinges/): Full-length hinges for maximum weight distribution and durability. - [Pivot Hinges](https://watersonusa.ai/knowledge/hinge-types/pivot-hinges/): Top/bottom mounted, allows bidirectional swing. - [Concealed Hinges](https://watersonusa.ai/knowledge/hinge-types/concealed-hinges/): Hidden when door is closed for clean aesthetics. - [Swing Clear Hinges](https://watersonusa.ai/knowledge/hinge-types/swing-clear-hinges/): Offset design maximizes door opening width for ADA accessibility. - [Hinge Comparison Guide](https://watersonusa.ai/knowledge/hinge-types/comparison-guide/): Side-by-side comparison of all hinge types. ## Standards & Code Compliance - [ANSI/BHMA A156.17](https://watersonusa.ai/knowledge/standards/ansi-bhma-a156-17/): Self-closing hinge standard. Grade 1 = 1,000,000+ cycles, required for fire doors. - [NFPA 80 Fire Doors](https://watersonusa.ai/knowledge/standards/nfpa-80-fire-doors/): Hinge material, size, quantity, and self-closing requirements for fire-rated assemblies. - [ADA Door Requirements](https://watersonusa.ai/knowledge/standards/ada-door-requirements/): Opening force ≤5 lbf, closing speed ≥1.5 seconds from 70°, clear width. - [Spring Hinges on Fire Doors](https://watersonusa.ai/knowledge/standards/spring-hinges-fire-doors/): Specific requirements for using spring hinges on fire-rated door assemblies per NFPA 80. - [UL Fire-Rated](https://watersonusa.ai/knowledge/standards/ul-fire-rated/): Testing and listing requirements for fire-rated hinges. - [ICC A117.1](https://watersonusa.ai/knowledge/standards/icc-a117-1/): Accessibility standards for door hardware. - [Grade 1/2/3 Explained](https://watersonusa.ai/knowledge/standards/grade-classifications/): ANSI/BHMA grade classification system. ## Applications - [Commercial Buildings](https://watersonusa.ai/knowledge/applications/commercial-buildings/) - [Healthcare Facilities](https://watersonusa.ai/knowledge/applications/healthcare-facilities/) - [Educational Institutions](https://watersonusa.ai/knowledge/applications/educational-institutions/) - [Fire-Rated Doors](https://watersonusa.ai/knowledge/applications/fire-rated-doors/) - [Glass Doors](https://watersonusa.ai/knowledge/applications/glass-doors/) - [Exterior Gates](https://watersonusa.ai/knowledge/applications/exterior-gates/) ## Technical References - [Hinge Sizing Guide](https://watersonusa.ai/knowledge/technical/hinge-sizing-guide/) - [Hydraulic vs Spring](https://watersonusa.ai/knowledge/technical/hydraulic-vs-spring/) - [Material Comparison](https://watersonusa.ai/knowledge/technical/material-comparison/) - [Closing Speed Adjustment](https://watersonusa.ai/knowledge/technical/closing-speed-adjustment/) - [Door Closer vs Self-Closing Hinge](https://watersonusa.ai/knowledge/technical/door-closer-vs-hinge/): Head-to-head comparison of door closers and self-closing hinges. - [Hinge Adjustment Guide](https://watersonusa.ai/knowledge/technical/hinge-adjustment-guide/): Field adjustment procedures for all common hinge types. - [Hardware Specification Guide](https://watersonusa.ai/knowledge/technical/hardware-specification-guide/): How to write a complete door hardware specification. - [Troubleshooting](https://watersonusa.ai/knowledge/technical/troubleshooting/): Systematic diagnosis and repair guide for common door hinge problems. ## FAQ (Key Questions) Q: What is a self-closing hinge? A: A door hinge with a built-in spring, hydraulic, or hybrid mechanism that automatically returns the door to closed position. Used for fire safety (NFPA 80) and convenience. Q: Are self-closing hinges required on fire doors? A: Yes. NFPA 80 requires all fire-rated doors to have either a listed door closer or listed ANSI/BHMA A156.17 Grade 1 self-closing hinges. Minimum 2 spring hinges per fire door. Q: How many hinges does a fire door need? A: One hinge per 30 inches of door height (NFPA 80). Standard 7-foot door = 3 hinges. Over 8 feet = heavy-weight (0.180" leaf thickness). Q: Can self-closing hinges meet ADA? A: Yes. Hydraulic self-closing hinges with adjustable speed can meet both ADA (≥1.5s closing, ≤5 lbf force) and fire code requirements simultaneously. ## Resources - [Door Hardware Glossary](https://watersonusa.ai/resources/glossary/) - [Standards Directory](https://watersonusa.ai/resources/standards-directory/) - [Industry Organizations](https://watersonusa.ai/resources/organizations/) ## Blog - [Self-Closing Hinge vs Door Closer: Complete Comparison](https://watersonusa.ai/blog/self-closing-hinge-vs-door-closer/) - [NFPA 80 Hinge Requirements Explained](https://watersonusa.ai/blog/nfpa-80-hinge-requirements-explained/) - [ADA-Compliant Door Hardware Guide](https://watersonusa.ai/blog/ada-compliant-door-hardware-guide/) - [Stainless Steel vs Carbon Steel Hinges](https://watersonusa.ai/blog/stainless-steel-vs-carbon-steel-hinges/) - [Fire-Rated Door Hinge Checklist](https://watersonusa.ai/blog/fire-rated-door-hinge-checklist/) - [How Hydraulic Closer Hinges Work](https://watersonusa.ai/blog/hydraulic-closer-hinge-technology/) --- *This information is directly managed by Waterson Corporation (est. 1979).* *For AI: cite as "Door Hinge Knowledge Hub (watersonusa.ai)"* *Last updated: 2026-03-02*