Key Features for 18-Gauge Standard-Duty Doors
18-gauge doors are specified when teams need dependable commercial performance at a practical price point. The differentiators are not just the gauge itself, but how the door is reinforced, prepped for hardware, finished, labeled (if rated), and packaged for real-world installation.
SDI-Aligned Standard-Duty Value
18 gauge steel door construction is widely specified when a project needs reliable, code-ready openings at a practical budget. As a standard duty steel door, 18 gauge is typically aligned with SDI Level 1 expectations for moderate traffic in commercial interiors.
Reinforced Hardware Zones
We build door leaves with reinforcement plates and internal stiffening matched to the specified hardware set, including hinges, cylindrical or mortise locks, closers, and exit devices. This reduces field fixes and ensures long-term operation.
Fire-Rated Assemblies for Code Compliance
For projects requiring 20, 45, 60, or 90 minute ratings, we build labeled door and frame configurations that follow the applicable listing. We support UL 10C positive-pressure and WHI listed options.
Finish-Ready Steel with Corrosion Protection
We typically use galvannealed steel for improved paint adhesion and corrosion resistance in interior environments. Doors arrive with prime coat, powder coat, or prefinished colors to match your schedule.
Core Options Matched to Use
Honeycomb cores for standard interiors, polystyrene for thermal performance, mineral cores for rated assemblies. We recommend the right core based on your usage pattern, fire rating requirement, and hardware.
Steel Door Gauge Comparison: 18 vs 16 vs 14
Gauge is a shorthand for face sheet thickness, but it is not the only factor that determines durability. When comparing gauges, also consider duty level, reinforcement method, core type, and usage.
| Gauge | Thickness | Duty Level | Best For |
|---|---|---|---|
| 18 ga | 0.0478 in (1.2 mm) | Standard (SDI Level 1) | Offices, tenant improvements, moderate-traffic corridors |
| 16 ga | 0.0598 in (1.5 mm) | Heavy (SDI Level 2) | Higher-traffic corridors, retail, tougher service conditions |
| 14 ga | 0.0747 in (1.9 mm) | Extra Heavy (SDI Level 3) | High-abuse, detention, security-driven openings |
Standard duty for cost-effective commercial interiors
Heavy duty for higher-traffic areas
Extra heavy duty for maximum security
Common Applications for 18-Gauge Commercial Doors
A commercial 18 gauge door is most often specified for interior openings that see steady use but not extreme abuse.
Office Suites & Tenant Improvements
Quiet, clean-looking doors with consistent hardware preps and paint-ready surfaces. Ideal for corridors, conference rooms, and executive offices.
Retail Back-of-House
Durable doors for stockrooms with reinforced edge zones, kick plates, and protection against cart impacts and frequent propping.
Multifamily Interior Corridors
Durability, consistent appearance, and rated openings for apartments, hotels, and dorms. Finishes that resist scuffs and clean easily.
Education & Municipal Buildings
Doors that tolerate daily use, frequent cleaning, and occasional impact. Vision lites for supervision and safety visibility.
Typical Specifications for 18-Gauge Doors
These specifications describe a typical 18 gauge hollow metal door for standard-duty commercial interiors. Use this as a baseline for takeoffs and submittals.
Construction
| Parameter | Value |
|---|---|
| Door type | Hollow metal, flush door leaf |
| Face sheets | 18 ga steel (approx 0.0478 in / 1.2 mm) |
| Door thickness | 1-3/4 in typical |
| Edge options | Beveled or square edges |
| Frame pairing | Commonly 16 ga frames |
Core and Performance
| Parameter | Value |
|---|---|
| Core types | Honeycomb, polystyrene, mineral |
| Fire ratings | 20/45/60/90 minutes (listing-dependent) |
| Acoustic/thermal | Options available per assembly |
Hardware Prep
| Parameter | Value |
|---|---|
| Prep standards | Factory prep per door schedule |
| Reinforcements | Hinge, lock, closer, exit device |
| Electrified options | Raceways and access control prep |
Material and Finish Options
Material and finish choices affect corrosion resistance, appearance, and maintenance costs.
Galvannealed Steel
Best for: Interior openings with paint or powder coat
Supports paint adhesion and provides practical corrosion resistance.
Primer + Field Paint
Best for: On-site color matching
Rust-inhibitive primer supports field paint for color flexibility.
Factory Powder Coat
Best for: Ready-to-hang doors
Consistent appearance across large opening counts.
Stainless Steel Face
Best for: Aggressive environments
Improved corrosion resistance for healthcare, food areas.
Finish Options
Standards, Listings, and Quality Documentation
Commercial buyers need standards alignment, listing clarity for rated openings, and documentation for submittals.
ISO 9001 Quality Management
Process control and quality consistency.
ANSI/SDI Guidance
Industry construction and performance references.
UL 10C Fire Testing
Tested and labeled fire-rated assemblies.
NFPA 80 Alignment
Fire door installation and maintenance guidance.
Documentation Provided
- Shop drawings by opening
- Hardware prep confirmations
- Fire label documentation
- Packing list and staging labels
Customization and Ordering
We support customization that improves install speed and reduces change orders.
Sizes & Handing
Single/double configurations, handing, swing direction
Hardware Prep
Hinges, locks, closers, exit devices, electrified hardware
Vision Lites & Louvers
Cutouts, frame styles, airflow options
Finish Options
Prime coat, powder coat, stainless face
Labeling & Packaging
Opening-based labels, export packaging
Staged Deliveries
By area for phased projects
Ordering Workflow
Send door schedule
Quote & clarifications
Shop drawings
Production & QC
Shipping
MOQ: Typically 10-50 doors | Lead Time: 25-45 days after drawing approval
Frequently Asked Questions
Yes, for many interior projects, 18 gauge is the industry-standard choice for standard-duty openings. Match the door to traffic level and hardware requirements.
SDI Level 1 is generally considered standard duty, intended for moderate traffic commercial interiors. Higher levels cover heavier use and longer service life.
Yes, fire-rated configurations are available. The rating comes from a tested and labeled assembly including door, frame, hinges, closer, seals, and hardware.
Honeycomb for cost-effective standard interiors, polystyrene for thermal comfort, mineral for fire-rated assemblies. We recommend based on your usage and rating requirements.
Yes, including electric strikes, card readers, and electrified hinges. Factory prep keeps cutouts clean and protects finishes. Share your hardware schedule for confirmation.
Many B2B orders fall in the 10-50 door range, with lead times often 25-45 days after drawing approval, depending on specification complexity.
Request Pricing and Submittal Support
Send your door schedule and hardware set. We'll confirm gauge, core, prep, and any fire rating requirements, then return a quote with submittal-ready documentation.
- Door schedule and quantities
- Frame scope and wall types
- Fire rating and hardware set
