Interior Steel Door Direct From Factory
1.0–1.2mm SPCC cold-rolled steel body, automated powder coating in 60+ colors, 100% pre-shipment inspection on every unit. Standard and custom configurations from 50 units MOQ.
What the Interior Steel Door Is —
and Where It Sits in Our Range
The interior steel door is the workhorse of the commercial door category: a single-leaf, flush or lightly embossed steel door designed for interior partition openings in commercial, institutional, and residential construction. No fire rating, no security reinforcement — just a well-made steel door that fits the opening, hangs straight, and holds its finish across years of daily use.
Within our steel door range, this product occupies the volume end of the spectrum. It's the door a distributor stocks in quantity because it moves consistently across multiple project types. It's the SKU a contractor specifies for interior corridors, utility rooms, and stairwell access points where the spec calls for steel but doesn't require a fire rating or elevated security class.
We've been manufacturing this product since 2008. The design hasn't changed dramatically because it doesn't need to — what's changed is the process precision behind it. Tighter dimensional tolerances, better pre-treatment chemistry, and a fully automated powder line have turned what used to be a commodity product into something that generates very few warranty calls from our buyers' downstream customers.
Where This Door Fits in Our Range
This page covers the straightforward interior steel door — the one that makes up the bulk of most commercial door orders. If your project requires a different performance tier:
Technical Specifications
Specifications shown are industry-standard values for this product type. Actual specifications may vary by configuration. Contact us for detailed product data sheets and exact dimensions.
| Parameter | Standard Value |
|---|---|
| Door leaf thickness | 45mm (typical) |
| Steel body gauge | 1.0–1.2mm SPCC cold-rolled steel |
| Frame material | 1.2–1.5mm SPCC cold-rolled steel |
| Internal fill | Honeycomb paper core (standard) / mineral wool (acoustic option) |
| Standard door sizes | 800×2000mm, 900×2000mm, 1000×2100mm (custom sizes available) |
| Surface finish | Automated electrostatic powder coat, 60–80μm film thickness |
| Color options | 60+ RAL colors standard; custom RAL on request |
| Hardware | 3× ball-bearing hinges, mortise lock, lever handle (upgradeable) |
| Frame profile | Standard rebated frame; KD (knock-down) flat-pack for shipping |
| Weight (approx.) | 35–55kg depending on size and fill |
| Certifications |
ISO 9001:2015 CE SGS
|
Choosing Your Gauge: 1.0mm vs 1.2mm
Standard recommendation for most commercial interior applications — office corridors, apartment buildings, institutional interiors.
Higher-abuse environments — schools, healthcare facilities, light industrial. Adds roughly 8–10% to unit weight, which affects your container loading count.
Worth factoring the weight delta into your landed cost calculation before you commit to a spec.
Core Fill: Standard vs Acoustic
Keeps weight manageable and provides adequate rigidity for interior use. Default for most commercial orders.
Improves sound attenuation meaningfully for hotel corridors, conference room partitions, medical facilities. No change to external profile or hardware configuration.
Need Full Product Data?
Request our detailed spec sheet with exact tolerances, finish test data, and hardware upgrade options.
Request a Spec SheetProduction Process: Where Consistency Comes From
The interior steel door looks simple. The margin risk is in the details that buyers can't see until the doors are on-site: panels that are 2mm out of square, powder coat that bubbles at weld seams six months after installation, frames that don't fit the leaf because tolerances drifted between production batches.
CNC Laser Cutting & Forming
We cut door panels and frames from SPCC cold-rolled steel coil on CNC laser cutting equipment, holding dimensional tolerances within ±0.5mm. That spec matters for field installation — when a contractor is hanging 200 doors in a building, they need every frame-to-leaf fit to be consistent, not adjusted unit by unit. After forming on CNC press brakes, panels go through robotic MIG welding on the standard lines.
Robotic MIG Welding
Robotic welding gives us consistent weld penetration across long runs — your 300th door off the line is dimensionally identical to your first. This is the difference between a production line and a workshop: repeatability at scale, not skilled-hand variation.
Zinc Phosphate Pre-Treatment
Before powder coating, every door body goes through our zinc phosphate pre-treatment bath. We switched from iron phosphate to zinc phosphate in 2020 after seeing adhesion failures on coastal-market orders — the zinc phosphate bonds to the steel substrate at a molecular level and gives the powder coat a foundation that survives humidity cycling without delaminating.
Why Weld Seam Pre-Treatment Matters
The most common defect we see on competitor interior steel doors is powder coat adhesion failure at weld seams — the weld creates a surface chemistry change that the coating doesn't bond to properly if the pre-treatment step is skipped or rushed.
We grind and re-treat every weld seam before the door enters the pre-treatment line. It adds a step, but it's the step that keeps your RMA rate at zero.
5-Stage QC: What Gets Checked Before Your Container Loads
Every interior steel door that ships under the EUWOO name passes through five inspection checkpoints. The full QC system is documented in our ISO 9001:2015 certified process — here's what it means for your specific order.
Incoming Steel Inspection
Every coil checked for gauge and surface condition before cutting. Off-spec material gets rejected, not used.
Post-Forming Dimensional Check
Panels and frames measured against master templates after CNC forming. Anything outside ±0.5mm tolerance is pulled before welding.
Weld Inspection
Every weld joint visually confirmed for full penetration and surface finish before pre-treatment.
Coating Inspection
Film thickness measured with a digital gauge after powder coating; surface checked for pinholes, orange peel, and edge coverage under controlled lighting.
Final Assembly & Pre-Shipment
Every door test-fitted with its frame, hardware cycled, squareness and gap consistency confirmed. 100% of units inspected — no statistical sampling.
100% Outgoing Inspection
Not AQL sampling — every unit
Our QC manager came from a Tier-1 automotive stamping supplier where statistical sampling on safety-relevant parts wasn't acceptable. We applied the same standard to doors.
What this means for your order:
Your container arrives right the first time. No sorting on-site. No RMA logistics. No project delays from a batch of out-of-spec doors discovered after the container is unloaded.
Market Segments: Where This Door Generates Repeat Volume
The interior steel door's commercial value for distributors and contractors is its breadth of application. It fits a wide range of project types without requiring specialized specification or installation knowledge, which means it moves consistently and generates reorder patterns rather than one-off project buys.
Residential Construction & Real Estate Development
The highest-volume segment for most distributors. Apartment buildings, condominiums, and mixed-use residential projects specify interior steel doors for unit entry doors, stairwell access, utility rooms, and basement corridors.
A mid-size residential tower might specify 300–600 interior steel doors across multiple unit types. Developers building multiple projects in a market create the kind of annual volume that justifies a dedicated SKU in your catalog.
Institutional & Government Construction
Schools, hospitals, government offices, military facilities — this segment runs on annual procurement budgets and standardized specifications. Once your interior steel door is written into a facility's standard spec, reorders follow the construction schedule automatically.
The steel door's durability advantage over hollow-core wood is the selling point: lower lifecycle replacement cost, which procurement officers can quantify and justify to budget committees. This segment has grown steadily in the Middle East and Southeast Asia — worth building relationships with institutional procurement channels if you're in those markets.
Light Commercial & Office Fit-Out
Office buildings, retail centers, hotels, service facilities — these projects specify interior steel doors for back-of-house areas, service corridors, plant rooms, and storage.
Typically smaller in unit count than residential or institutional, but they run on tight schedules and need reliable supply. A contractor who can count on consistent lead times and dimensional accuracy across a 50-unit fit-out order becomes a repeat buyer.
OEM & Private-Label Programs
For regional door brands and building material distributors who want to sell under their own label. Full program support: your branding on the door, your packaging, your documentation.
MOQ for private-label: 100 units — the minimum where powder line changeover and label setup cost makes sense for both sides.
Why Distributors Reorder
- Fits residential, institutional, and commercial specs without specialized knowledge
- Once written into a facility spec, reorders follow the construction schedule automatically
- Lower lifecycle replacement cost vs. hollow-core wood — a quantifiable argument for procurement
- Private-label program available from 100 units with full branding and documentation support
Customization: What You Can Specify, What You Can't, and What It Costs You
Interior steel doors are one of the more customizable products in our range because the base construction is straightforward — changes to size, gauge, finish, and hardware don't require new tooling in most cases.
Size
Standard catalog sizes cover the most common commercial opening dimensions.
Openings outside this range require a tooling discussion.
Steel Gauge
Both gauges are standard stock — no MOQ premium for gauge selection.
Surface Finish
60+ RAL colors from standard powder library at no additional cost.
Internal Fill
Default configuration, lower unit weight and cost
Adds to unit weight and cost — we'll quote both options so you can make the margin calculation
Hardware
Standard: 3× ball-bearing hinges, mortise lock, lever handle.
Hardware upgrades affect lead time — confirm your hardware spec before placing the order, not after.
Frame Configuration
Ships flat-pack — optimal container loading efficiency
Pre-assembled units reduce container loading efficiency by approx. 30–40% vs. KD — affects your landed cost
MOQ Summary
Minimum order quantities by configuration type.
Spec Before You Order
Hardware upgrades, custom colors, and frame type all affect lead time and landed cost. Lock in your full specification before placing the order — changes after confirmation add delays and cost on both sides.
Container Loading and Landed Cost Planning
Interior steel doors ship in KD (knock-down) flat-pack format — door leaf, frame components, and hardware packed separately in reinforced cartons. This is the format we developed specifically for long-haul export freight after early orders arrived with damage from port handling.
Every carton carries a barcode linked to our production batch record. If there's a quality question on arrival, you can trace the unit back to its production date, line, and inspection record within minutes — useful for your own import compliance documentation and for resolving any downstream customer claims quickly.
Container Capacity Reference
Numbers vary by door size and configuration. Use these figures for landed cost per unit calculations.
Lead Time
Standard catalog interior steel doors: 25–35 days from deposit confirmation. Custom configurations are quoted individually.
KD vs Pre-Hung: The Freight Math
KD format delivers 30–40% better container utilization versus pre-hung assemblies
Lower freight cost per unit — most experienced buyers default to KD unless customers specifically require pre-assembled
Installation time per door: 20–40 minutes with basic tools for experienced contractors
Documentation Package
Complete for customs clearance in all active markets — Los Angeles, Houston, Dubai, Singapore, Lagos, Sydney.
Frequently Asked Questions
Decision-support answers for importers, distributors, and project specifiers.
What steel gauge should I specify for interior steel doors in high-traffic commercial environments?
For standard office and residential interior use, 1.0mm SPCC cold-rolled steel is sufficient — it handles normal daily cycling without deformation. For high-abuse environments (schools, healthcare corridors, light industrial facilities), specify 1.2mm gauge with reinforced hinge zones. Past 1.5mm body thickness on an interior door, you're adding freight weight without meaningful performance gain for non-security applications — that's the territory of security doors, not standard interior steel.
What is the difference between an interior steel door and an interior fire door?
The interior steel door has no fire rating — it's a standard steel door for interior openings where the building code doesn't require fire separation. An interior fire door carries a tested fire resistance rating (typically 30, 60, or 90 minutes) and requires certified hardware, intumescent seals, and a self-closing mechanism to maintain that rating.
If your project spec calls for fire separation between compartments, you need the interior fire door, not this product. If the spec just calls for a steel door in an interior opening, this is the right product and the more cost-effective one.
What is the minimum order quantity for custom sizes or colors?
Standard catalog sizes and colors
Custom sizes (outside standard range) or custom RAL colors
The 100-unit threshold is where the powder line changeover and any tooling setup cost is absorbed without pricing the customization out of your margin. Below 100 units on a custom color, the per-unit cost of the changeover makes the economics difficult for both sides.
How does KD flat-pack affect installation on the receiving end?
KD format means the door leaf, frame, and hardware ship as separate components and are assembled on-site. For experienced contractors, this is standard practice — installation time per door is 20–40 minutes with basic tools.
For distributors selling to less experienced installers, we can provide installation instruction sheets in your language as part of the OEM package. The trade-off is clear: KD gives you 30–40% better container utilization and lower freight cost per unit versus pre-hung assemblies.
Can interior steel doors be used for exterior applications?
Not recommended — will generate warranty claims.
Standard interior steel doors are not designed for exterior exposure — the honeycomb paper core absorbs moisture, and the standard powder coat spec is not rated for continuous UV and weather exposure.
For exterior openings, the correct product is from our exterior door range or our steel security door line, both of which use weatherproof construction and appropriate sealing.
What certifications does the interior steel door carry?
These cover the manufacturing process and product conformity for most commercial import requirements in North America, Europe, the Middle East, and Southeast Asia.
SGS audit reports are available on request for buyers who need third-party documentation for their own import compliance files. NFPA 80 certification applies to our fire door range, not to standard interior steel doors.
Related Products in the Steel Door Range
Explore adjacent products in the EUWOO steel door lineup — each optimized for a specific application, load cycle, or compliance requirement.
Industrial Steel Door
Heavy-duty interior openings, high-cycle factory and warehouse use
Office Steel Door
Commercial office fit-out with aesthetic finish requirements
Residential Steel Door
Residential unit entry and interior applications
Interior Fire Door
Interior openings requiring fire separation rating
Interior Security Door
Interior openings requiring elevated security classification
Steel Door Frame
Replacement or standalone frame supply
Get a Quote for Interior Steel Doors
Send us your target spec — door size, gauge, color, hardware configuration, and volume — and our team will come back with a detailed quote, container loading calculation, and lead time confirmation.
If you're building a private-label program or entering this product category for the first time, tell us your target market and volume expectations and we'll suggest a starter configuration based on what's moving for our existing distributors in that region.
Contact Our Sales Team
Include your target spec, volume, and destination market for the fastest turnaround on pricing and container planning.