400mm Aluminum Circle
A 400mm aluminum circle is a flat, round aluminum disc with a diameter of exactly 400 millimeters. It is one of the most commonly ordered sizes in the aluminum circle product family. Manufacturers and buyers worldwide choose this specific size for cookware, lighting reflectors, road signs, nameplates, and a wide range of industrial applications.
The 400mm aluminum circle sits in the medium-to-large diameter range. It is large enough for standard frying pans, woks, and medium-sized pots. It is also a popular choice for road sign blanks, decorative panels, and circular machine components.
This guide covers everything you need to know about 400mm aluminum circles — from alloy grades and thickness options to applications, surface finishes, and how to place an order.
What Is a 400mm Aluminum Circle?
A 400mm aluminum circle (also called a 400mm aluminium disc or 400mm aluminum circle plate) is a precision-cut round aluminum blank. The diameter is 400mm. The thickness varies depending on the application — from 0.5mm for lightweight reflectors to 4.0mm for heavy-duty cookware or structural uses.
Common Names for This Product
- 400mm aluminum circle
- 400mm aluminium circle
- 400mm aluminum disc
- 400mm aluminum circle plate
- 400mm aluminum circle sheet
- 400mm round aluminum blank
All these terms refer to the same product. The key dimensions are:
- Diameter: 400mm (±0.5mm standard tolerance)
- Thickness: 0.3mm – 6.0mm (sheet) or 6mm+ (plate)
Why 400mm Is a Popular Diameter
The 400mm diameter is one of the most frequently ordered sizes for several practical reasons:
Cookware
A 400mm circle is the ideal blank size for:
- 36cm–38cm frying pans (standard large size)
- 36cm woks (after deep drawing, the diameter reduces)
- Medium-to-large pressure cooker bodies
- Large stock pot bottoms
When aluminum circles are deep drawn into cookware, the diameter reduces and the walls form upward. A 400mm blank typically produces a 280mm–320mm finished diameter pan after forming.
Road Signs
400mm is a standard diameter for many circular road signs worldwide. Traffic management authorities in Europe, Asia, and the Middle East commonly specify 400mm round sign blanks.
Industrial Discs
400mm provides a useful size for:
- Machine base plates and spacers
- Flange blanks
- Filter plates
- Valve discs
Alloy Options for 400mm Aluminum Circles
The right alloy depends entirely on your application. Here are the most common alloy choices for 400mm aluminum circles:
1050 Aluminum Circle 400mm
- Aluminum content: ≥ 99.5%
- Excellent surface finish after polishing
- Best choice for lighting reflectors
- High thermal conductivity
- Food safe
- Temper: O for deep drawing, H14 for flat applications
- Best for: Cookware, lighting reflectors, chemical equipment
1060 Aluminum Circle 400mm
- Aluminum content: ≥ 99.6%
- Slightly higher purity than 1050
- Excellent corrosion resistance
- High electrical conductivity (61% IACS)
- Food safe and chemical resistant
- Best for: Electrical components, chemical tanks, cookware
1100 Aluminum Circle 400mm
- Aluminum content: ≥ 99.0%
- Good formability and workability
- Good surface for anodizing
- Popular in North American markets
- Best for: Cookware, nameplates, road signs, decorative panels
3003 Aluminum Circle 400mm
- Main alloy: Manganese (Mn 1.0–1.5%)
- About 20% stronger than 1050
- Excellent formability and corrosion resistance
- Food safe
- Temper: O for deep drawing, H14 for panels
- Best for: Pressure cookers, deep-drawn cookware, storage tanks, road signs
5052 Aluminum Circle 400mm
- Main alloy: Magnesium (Mg 2.2–2.8%)
- Higher strength than 3003
- Excellent marine corrosion resistance
- Best for: Marine equipment, pressure vessels, structural discs
6061 Aluminum Circle 400mm
- Main alloys: Magnesium + Silicon
- High strength (310 MPa in T6)
- Excellent machinability
- Heat treatable
- Best for: Engineering parts, machine components, structural plates
Quick Alloy Selection Guide for 400mm Circles
| Application | Alloy | Temper |
|---|---|---|
| Deep-drawn frying pan | 1050, 1060, 3003 | O |
| Pressure cooker body | 3003, 5052 | O |
| Road sign blank | 3003, 1100 | H14 |
| LED reflector | 1050 | H14, polished |
| Machine disc | 6061 | T6 |
| Chemical tank lid | 1060, 3003 | O, H14 |
| Nameplate | 1050, 1100 | H14, H18 |
| Marine component | 5052 | H32 |
400mm Aluminum Circle Thickness Options
Choosing the right thickness is critical for your manufacturing process. Here is a complete thickness guide for 400mm aluminum circles:
Thickness Chart for 400mm Aluminum Circles
| Thickness | Weight per Piece | Common Application |
|---|---|---|
| 0.5mm | 170g | Lightweight reflectors, thin panels |
| 0.8mm | 272g | Light sign blanks, thin cookware |
| 1.0mm | 340g | Standard pots and pans |
| 1.2mm | 408g | Medium cookware, lid blanks |
| 1.5mm | 510g | Standard cookware, pressure cooker lids |
| 2.0mm | 680g | Heavy cookware, wok blanks |
| 2.5mm | 850g | Thick-base frying pans |
| 3.0mm | 1,020g | Heavy-duty cookware, sign plates |
| 4.0mm | 1,360g | Thick panels, industrial discs |
| 5.0mm | 1,700g | Heavy industrial discs |
| 6.0mm | 2,040g | Maximum sheet thickness |
Weight calculated using density 2.71 g/cm³ for approximate reference
Most Popular Thicknesses for 400mm Circles
For cookware:
- 1.5mm — standard frying pans and pots
- 2.0mm — woks and heavy-duty pans
- 2.5mm — thick-base premium cookware
For road signs:
- 2.0mm — standard road sign thickness
- 3.0mm — heavy-duty or highway signs
For reflectors:
- 0.5mm – 1.0mm — lightweight LED reflector blanks
For industrial discs:
- 3.0mm – 6.0mm — machine components and flanges
400mm Aluminum Circle Plate: Specifications
Standard Product Specifications
| Parameter | Specification |
|---|---|
| Diameter | 400mm (±0.5mm) |
| Thickness range | 0.3mm – 6.0mm (sheet) / 6mm+ (plate) |
| Alloy | 1050, 1060, 1100, 3003, 5052, 6061 |
| Temper | O, H12, H14, H16, H18, H24, T6 |
| Edge condition | Deburred (standard) |
| Surface finish | Mill, polished, brushed, mirror, anodized |
| Flatness tolerance | ≤ 1.5mm per meter |
| Diameter tolerance | ±0.5mm |
| Thickness tolerance | ±0.05mm |
International Standards
| Standard | Description |
|---|---|
| ASTM B209 | American standard |
| EN 573-3 | European alloy designation |
| EN 485-1/2 | European mechanical properties |
| GB/T 3880 | Chinese national standard |
| ISO 9001:2015 | Quality management |
Surface Finish Options for 400mm Aluminum Circles
The surface finish affects both the appearance and performance of your finished product. Here are the available options:
Mill Finish
The natural surface from the rolling and cutting process. No additional treatment. Slight surface variations may be present. Most economical option. Best for cookware blanks and industrial applications where surface appearance is not critical.
Polished Finish
Mechanical polishing creates a smooth, bright surface. Available in several levels:
Brushed / Satin Finish
A directional grain pattern. Creates a professional, decorative appearance. Popular for nameplates, signs, and architectural panels.
Standard Polish
Smooth, bright finish. Good for general decorative use and moderate-reflectivity lighting applications.
High Gloss Polish
Very bright, highly reflective surface. Used for premium lighting reflectors and decorative panels.
Mirror Finish (No.8)
Near-perfect reflectivity. The highest level of polish achievable. Used for high-performance LED reflectors and display applications.
Anodized Finish
Electrochemical anodizing creates a hard, protective oxide layer. Benefits:
- Excellent corrosion protection
- Hard surface (harder than the base metal)
- Can be colored in many shades
- Accepts laser engraving and printing
Available anodized colors for 400mm aluminum circles:
- Clear / natural
- Black
- Gold / champagne
- Blue
- Red
- Green
- Custom colors on request
Non-stick Coating
For cookware applications, non-stick coating is applied after forming (not before). We supply pre-formed 400mm circles ready for your coating process.
Applications of 400mm Aluminum Circles
Cookware Manufacturing
The 400mm aluminum circle is one of the most important sizes for cookware production. Here is how manufacturers use it:
Frying Pans (36cm)
A 400mm blank deep drawn on a hydraulic press produces a 36cm frying pan. The circle diameter reduces as the material flows up to form the walls. Draw ratio calculations determine the exact blank size needed.
Woks (36cm)
400mm blanks are commonly used for 36cm wok production. The deeper, more curved shape of a wok requires a slightly larger blank than a flat frying pan.
Pot Bottoms
Large pots use 400mm circles as base discs before welding or pressing the sides.
Pressure Cooker Bodies
400mm circles in 3003-O or 5052-O alloy are pressed into pressure cooker body shapes.
Why 400mm for cookware?
- Right size for standard large cookware (36cm finished diameter)
- Alloys 1050, 1060, and 3003 are food safe
- O temper provides maximum formability for deep drawing
- Good thermal conductivity for even cooking
Road Signs and Traffic Signs
400mm aluminum circle plates are widely used for circular road signs:
- Speed limit signs
- Warning signs
- No entry signs
- Parking restriction signs
- Pedestrian crossing signs
Standard specifications for sign blanks:
- Alloy: 3003-H14 or 1100-H14
- Thickness: 2.0mm or 3.0mm
- Surface: Mill finish (for reflective film application)
- Edge: Deburred, drilled holes optional
LED Lighting Reflectors
400mm polished aluminum circles serve as reflector blanks for:
- Large LED panel lights
- Industrial high-bay lighting
- Outdoor flood lights
- Stage and studio lighting equipment
Alloy 1050 with mirror finish provides the best reflectivity. After forming into a reflector shape, the 400mm circle becomes a light-focusing reflector.
Nameplates and Decorative Panels
400mm is a useful size for:
- Large equipment nameplates
- Decorative wall panels
- Art installations
- Architectural accent pieces
- Award plaques
Anodized 400mm circles accept laser engraving and sublimation printing for permanent, high-quality graphics.
Industrial and Engineering Applications
400mm aluminum circle plates (6mm+) are used for:
- Machine base discs and end caps
- Flange blanks for pipe connections
- Valve and pump components
- Filter housing plates
- Structural spacers and washers
6061-T6 alloy is preferred for these applications due to its high strength and machinability.
Chemical Equipment
400mm circles in 1060 or 3003 alloy serve as:
- Tank lid blanks
- Vessel end cap discs
- Filter plates
- Heat exchanger plates
How 400mm Aluminum Circles Are Produced
Step 1: Coil Preparation
We start with aluminum coil in the specified alloy and temper. The coil width is selected based on the circle diameter. For 400mm circles, we use coil widths of 420mm or wider.
Step 2: Stamping / Blanking
The coil feeds into a precision stamping press. A circular die of exactly 400mm (+tolerance allowance) punches the disc from the aluminum sheet. The stamping process is fast — producing hundreds of circles per hour.
For special requirements, we use:
- Laser cutting — for tight tolerances (±0.1mm)
- Water jet cutting — for thick plates without heat distortion
Step 3: Deburring
All cut edges are deburred using automated deburring machines. This removes sharp edges and ensures safe handling.
Step 4: Flatness Check
Each disc is checked for flatness. Any bowed discs go through a leveling press.
Step 5: Surface Treatment
Based on your order:
- Polishing (brushed, high gloss, mirror)
- Anodizing (clear or colored)
- Custom coating
Step 6: Quality Inspection
Every batch is inspected:
- Diameter: measured with precision caliper
- Thickness: checked at multiple points
- Surface: visual inspection for scratches, pits, inclusions
- Flatness: checked with straight edge
- Weight: spot check for consistency
Step 7: Packaging
400mm aluminum circles are packed with:
- Interleaf paper between each disc
- Plastic stretch wrap around the stack
- Wooden pallet or export carton
- Clear labeling: alloy, temper, thickness, quantity
400mm Aluminum Circle vs Other Diameters
To help you choose the right size, here is how 400mm compares to adjacent sizes:
| Diameter | Typical Weight (2mm) | Common Application |
|---|---|---|
| 300mm | 383g | 28cm frying pans, small signs |
| 350mm | 522g | 32cm cookware, medium signs |
| 400mm | 680g | 36cm cookware, standard road signs |
| 450mm | 861g | 40cm woks, large cookware |
| 500mm | 1,062g | 46cm woks, large industrial discs |
If you need a slightly smaller blank for 34cm cookware, a 380mm circle is the right choice. For 38cm pans, a 420mm circle may be more appropriate depending on your draw ratio.
Aluminium Discs Circles: Custom Sizes Available
While 400mm aluminum circle is a popular standard size, we supply aluminium discs circles in any diameter from 80mm to 1500mm. Custom diameters are available with the same lead times as standard sizes.
Common Diameter Range
| Size Range | Typical Application |
|---|---|
| 80mm – 200mm | Small pans, nameplates, tags |
| 200mm – 350mm | Medium cookware, signs |
| 350mm – 500mm | Large cookware, road signs |
| 500mm – 800mm | Industrial discs, large signs |
| 800mm – 1500mm | Large industrial plates |
How to Order 400mm Aluminum Circles
When placing your order, provide these details:
- Diameter: 400mm (confirm tolerance requirement)
- Thickness: in mm (e.g., 1.5mm, 2.0mm, 3.0mm)
- Alloy: 1050, 1060, 1100, 3003, 5052, or 6061
- Temper: O, H12, H14, H16, H18, H24, or T6
- Surface finish: mill, polished, brushed, mirror, anodized
- Edge condition: deburred (standard) or machined
- Quantity: number of pieces or weight in kg
- Standard: ASTM B209, EN 485, GB/T 3880
- Special requirements: center hole, custom packaging, certifications
- Destination port: for shipping cost calculation
Why Choose Us for 400mm Aluminum Circles?
We are a professional manufacturer of 400mm aluminum circles and all other aluminum disc sizes. Here is why buyers worldwide choose us:
In-Stock Availability
We maintain stock of the most popular 400mm circle specifications:
- 1050-O: 1.0mm, 1.5mm, 2.0mm, 2.5mm
- 3003-O: 1.0mm, 1.5mm, 2.0mm, 2.5mm, 3.0mm
- 1100-H14: 2.0mm, 3.0mm
- 3003-H14: 2.0mm, 3.0mm
Stock orders ship in 3–7 days.
Custom Production
We produce any alloy, temper, thickness, and surface finish combination. Custom orders ship in 15–25 days.
Strict Quality Control
Every batch includes:
- Chemical composition certificate (OES test)
- Mechanical property test report
- Dimensional inspection record
- Surface quality inspection
Competitive Factory Pricing
Direct manufacturer. No middlemen. Volume discounts available for orders above 500kg, 1MT, and 5MT.
Global Export Experience
We export 400mm aluminum circles and other sizes to the USA, Germany, UK, Australia, Canada, UAE, Turkey, Egypt, South Korea, Vietnam, and 60+ other countries.
Technical Support
Our team helps you select:
- The right alloy for your forming process
- The correct temper for your draw ratio
- The best surface finish for your end product
Frequently Asked Questions
What is a 400mm aluminum circle used for?
A 400mm aluminum circle is most commonly used for manufacturing 36cm frying pans and woks, road signs, LED lighting reflectors, nameplates, and industrial machine discs. It is one of the most popular sizes in cookware manufacturing worldwide.
What alloy is best for 400mm aluminum cookware circles?
For deep-drawn cookware, the best alloys are 1050-O, 1060-O, and 3003-O. The O temper (annealed) provides maximum formability for deep drawing without cracking. 3003 is preferred when more strength is needed in the finished cookware.
What thickness should I choose for a 400mm aluminum circle for frying pans?
For standard frying pans, 1.5mm to 2.0mm is the most common thickness. For premium thick-base pans, 2.5mm to 3.0mm is used. The exact thickness depends on your draw ratio and the desired final wall thickness of the pan.
Can I get a 400mm aluminum circle with a center hole?
Yes. We can punch a center hole of any diameter in your 400mm aluminum circles. Please specify the center hole diameter when ordering.
What is the weight of a 400mm aluminum circle at 2mm thickness?
A 400mm aluminum circle at 2.0mm thickness weighs approximately 680 grams (calculated using aluminum density of 2.71 g/cm³).
Do you supply 400mm aluminum circles in anodized finish?
Yes. We supply 400mm aluminum circles in anodized finish — clear, black, gold, blue, red, and custom colors. Anodized circles are popular for nameplates, decorative panels, and signs.
What is the minimum order quantity for 400mm aluminum circles?
MOQ varies by specification. For standard alloys and thicknesses, we offer flexible MOQ. Contact us with your exact requirements and we will confirm pricing and MOQ for your order.
