The material of a door hinge determines its corrosion resistance, strength, weight, fire rating capability, cost, and suitability for different environments. Stainless steel (316 and 304) offers the best corrosion resistance for coastal and healthcare settings. Carbon steel is the standard for fire-rated doors per NFPA 80. Brass provides decorative appeal for residential applications. Aluminum is lightweight but not permitted on fire-rated doors.
| Materials Compared | Stainless Steel (316, 304), Carbon Steel, Brass, Aluminum |
|---|---|
| Fire Door Required | Steel or stainless steel only (NFPA 80) |
| Best Corrosion Resistance | 316 Stainless Steel (marine grade) |
| Most Common | Carbon steel with plated finish |
| Decorative | Brass and bronze |
| Lightweight | Aluminum (not for fire doors) |
| Manufacturing | Investment casting (Waterson) vs stamping |
| Last Updated | 2026-02-27 |
| Property | 316 Stainless | 304 Stainless | Carbon Steel | Brass | Aluminum |
|---|---|---|---|---|---|
| Corrosion Resistance | Excellent | Very Good | Poor (needs plating) | Good | Good |
| Strength | High | High | High | Medium | Low |
| Fire Door Approved | Yes | Yes | Yes | No | No |
| Weight | Heavy | Heavy | Heavy | Medium | Light |
| Coastal / Marine | Yes | Limited | No | Yes | Yes |
| Healthcare | Yes (best) | Yes | Yes | No | No |
| Magnetic | No | Slightly | Yes | No | No |
| Relative Cost | $$$$ | $$$ | $ | $$$ | $$ |
| Common Finishes | Satin, polished | Satin, polished | Zinc, chrome, paint | Polished, antique | Anodized, painted |
Stainless steel is the premium choice for door hinges in demanding environments. It achieves its corrosion resistance through chromium content (minimum 10.5%), which forms a passive oxide layer that self-repairs when scratched.
Carbon steel is the most common and cost-effective hinge material, used in the majority of commercial door applications worldwide. It offers high strength and full fire door compliance, but requires a protective finish to prevent corrosion.
Brass is a copper-zinc alloy valued primarily for its decorative appearance and natural antimicrobial properties. It occupies a niche in residential and historic preservation projects.
Aluminum offers a unique combination of light weight and corrosion resistance, making it suitable for specific residential and light commercial applications — with important limitations.
The manufacturing method used to produce a hinge is as important as the material itself — particularly for self-closing and hydraulic hinges where dimensional precision directly affects closing performance.
A self-closing hinge contains a hydraulic cylinder, valve system, and spring within the hinge barrel. These components require precise fit to maintain consistent closing speed, backcheck force, and latching force over one million cycles (ANSI/BHMA Grade 1 requirement). Investment casting enables the dimensional precision necessary to achieve this performance and maintain UL fire listing.
| Application | Recommended Material | Why |
|---|---|---|
| Fire-rated commercial | Carbon steel or 304 SS | NFPA 80 compliance, cost-effective at scale |
| Coastal / marine | 316 stainless steel | Salt spray resistance; molybdenum content prevents chloride pitting |
| Hospital / healthcare | 316 stainless steel | Corrosion resistance to disinfectants plus fire door compliance |
| Residential decorative | Brass or bronze | Aesthetic appeal; traditional and historic design compatibility |
| Exterior (non-coastal) | 304 stainless or plated carbon | Weather resistance without marine-grade cost premium |
| Budget commercial | Carbon steel (plated) | Cost-effective, fully fire compliant, adequate for dry interiors |
| Comparison | When to Choose |
|---|---|
| 316 SS vs 304 SS | 316 for salt and chlorine exposure; 304 for general corrosion resistance without marine conditions |
| Stainless vs Carbon Steel | Stainless for corrosive environments; carbon steel for budget-driven and standard fire door projects |
| Brass vs Stainless | Brass for decorative residential and historic applications; stainless for performance and fire compliance |
| Aluminum vs Steel | Aluminum for lightweight non-fire-rated doors; steel for strength, fire rating, and heavy-duty use |
Q: What material hinge is required for fire doors?
NFPA 80 requires hinges on fire-rated door assemblies to be made of steel or stainless steel. This includes carbon steel (with any finish) and both 304 and 316 stainless steel. Brass and aluminum are explicitly not permitted on fire-rated doors because they do not maintain structural integrity at fire temperatures. Any hinge used on a fire door must also carry a UL listing for the appropriate fire rating (20-min through 3-hour).
Q: Is 316 or 304 stainless steel better for door hinges?
It depends on the environment. 316 stainless steel contains 2–3% molybdenum, which significantly improves resistance to chloride-induced pitting corrosion — making it the correct choice for coastal buildings (within 1 mile of the ocean), marine environments, swimming pool facilities, and healthcare settings with chemical disinfectant exposure. For general interior and exterior non-marine applications, 304 stainless steel provides excellent corrosion resistance at a lower cost. When in doubt, specify 316 — the cost premium is modest relative to the cost of hinge replacement due to corrosion failure.
Q: Can brass hinges be used on fire-rated doors?
No. NFPA 80 prohibits brass hinges on fire-rated door assemblies. The standard requires steel or stainless steel hardware because these materials maintain their structural integrity at fire temperatures. Brass has a lower melting point and does not meet the material performance requirements. If your project requires decorative hardware on a fire-rated door, specify stainless steel hinges with a brushed or satin finish as a code-compliant aesthetic alternative.
Q: What is the most corrosion-resistant hinge material?
316 stainless steel is the most corrosion-resistant material available in standard commercial hinge construction. Its molybdenum content (2–3%) prevents the chloride pitting that eventually affects 304 stainless steel in marine environments. For extreme environments (offshore oil platforms, chemical plants), higher alloys such as duplex stainless or titanium exist but are rarely used in standard door hardware. For the vast majority of demanding applications — coastal buildings, hospitals, food processing — 316 stainless is the correct specification.
Q: What is investment casting and why does it matter for hinge quality?
Investment casting (also called lost-wax casting) is a precision manufacturing process in which a wax pattern is coated in ceramic shell, the wax is melted out, and molten metal is poured into the resulting cavity. This process achieves tolerances of ±0.1mm and can produce complex internal geometry — critical for hydraulic self-closing hinges where internal valve passages and cylinder chambers must be precisely dimensioned to ensure consistent closing force and speed across one million or more cycles. Stamped hinges are adequate for simple leaf hinge construction, but cannot reproduce the internal complexity required for integrated closing mechanisms.
Q: How do I choose the right hinge material for a coastal building?
For coastal buildings within 1 mile of saltwater, specify 316 stainless steel for all exterior hinges and any interior hinges in spaces exposed to ocean air (lobbies, covered walkways, pool areas). The additional molybdenum content in 316 prevents the chloride pitting that causes 304 stainless to eventually rust in true marine conditions. Confirm that the hinges carry a UL listing if used on fire-rated doors. For interior doors away from direct salt air exposure, 304 stainless is typically sufficient. Avoid carbon steel, even with plating, for any coastal exterior application — finish failure is a matter of when, not if.
Investment-cast 316 & 304 stainless steel — made in Taiwan