Views: 0 Author: Site Editor Publish Time: 2026-08-17 Origin: Site
You send the same drawing to three sheet metal manufacturers.
A few days later, you receive three quotations:
Supplier A: $180 per unit
Supplier B: $245 per unit
Supplier C: $360 per unit
The obvious question is:
Why are the prices so different?
For a custom sheet metal enclosure, the lowest quotation is not always quoting the same product.
One supplier may include internal brackets.
Another may quote only the external housing.
One price may include powder coating.
Another may exclude it.
One supplier may quote the required material thickness.
Another may use a thinner alternative.
This is why comparing only the final number can create problems later.
Before choosing a supplier, buyers should compare what is actually included in each quotation.
Here are 10 things worth checking.
The first thing to check is the exact material.
For example, two quotations may both simply say:
Steel enclosure
But this does not necessarily mean the same material specification is being quoted.
Depending on the project, the enclosure may use:
Iron / carbon steel
Galvanized steel
Aluminum
Stainless steel
The material directly affects:
Cost
Weight
Structural performance
Corrosion resistance
Surface finishing requirements
Before comparing prices, ask each supplier:
What material is included in this quotation?
A lower price may be based on a different material from the one you originally expected.
Thickness is another easy detail to overlook.
For example:
Supplier A: 1.0 mm
Supplier B: 1.5 mm
Supplier C: 2.0 mm
These quotations should not be compared as if they were identical.
Different thicknesses can affect:
Material cost
Product weight
Structural strength
Manufacturing requirements
Always check whether the quotation clearly specifies the sheet thickness.
If thickness is critical to your product, make sure it is confirmed before production.
This is one of the biggest reasons quotations vary.
A custom enclosure may include:
External panels
Doors
Covers
Internal mounting plates
Brackets
Support structures
Reinforcement parts
One supplier may quote everything.
Another may quote only the outer shell.
For example, a quotation that says:
Custom enclosure: $200
does not tell you enough.
You should ask:
Does this price include all internal structures shown in the drawing?
This is especially important for products such as:
EV charger enclosures
Industrial equipment housings
Electrical cabinets
BESS enclosures
The internal structure can represent a significant part of the manufacturing scope.
Custom sheet metal products often require many openings.
These may include:
Display cutouts
Connector openings
Cable entries
Button holes
Ventilation areas
Lock openings
Mounting holes
The external dimensions of two enclosures may be identical, but the manufacturing complexity may be completely different.
For example:
A simple box with a door.
The same size, but with:
A display opening
Multiple connector openings
Cable entries
Ventilation holes
Internal mounting holes
They should not have the same manufacturing cost.
When comparing quotations, confirm that all required cutouts and openings are included.
Some enclosure structures require welding.
Others are designed primarily around:
Bending
Mechanical fastening
Assembly
The amount of welding required can affect the manufacturing cost.
Ask:
What welding work is included in the quotation?
Also confirm whether the quotation includes:
Welding only
Welding and grinding
Welding with visible surface finishing
For customer-facing products, the appearance of welded areas may also be important.
A quotation that includes basic welding may not necessarily include additional finishing requirements.
This is another area where prices can appear similar at first but become different later.
For example:
Supplier A: Fabricated metal parts only
Supplier B: Powder coating included
Supplier C: Powder coating with specific color requirements included
These are different manufacturing scopes.
Before comparing prices, confirm:
Is powder coating included?
Is the required color included?
Are surface requirements clearly defined?
Do not assume that a quotation for a finished enclosure automatically includes every surface treatment requirement.
Custom enclosures may require hardware such as:
Hinges
Locks
Handles
Fasteners
Mounting hardware
One supplier may include these items.
Another may quote the metal parts only.
For this reason, check whether the quotation includes:
Fabricated enclosure + hardware
or:
Fabricated enclosure only
If hardware is not included, ask whether it will be:
Supplied by the buyer
Purchased separately
Added to the final quotation
This prevents unexpected costs later.
For projects requiring environmental protection, this should be clearly discussed before comparing prices.
For example, EV charger enclosure projects may require:
IP54
IP65
depending on the product design and application.
These requirements may affect details such as:
Door construction
Sealing areas
Panel joints
Cable entry design
Access openings
For LED display cabinet projects, MT Metal focuses specifically on:
IP65 waterproof cabinet structures.
If one supplier quotes a standard enclosure while another is quoting the required waterproof structural design, the prices are not directly comparable.
Always confirm:
Is the quoted structure designed according to the specified protection requirement?
Price comparisons should not stop when the enclosure leaves the production line.
Buyers should also understand what is checked before shipment.
Depending on the project, important checks may include:
Overall dimensions
Critical dimensions
Assembly fit
Surface appearance
Hardware installation
Structural completeness
If your product has critical requirements, identify them clearly.
For example:
The display opening dimensions are critical.
Or:
The mounting hole positions must match the internal component drawing.
This helps ensure the supplier understands which features require particular attention.
A quotation without a clearly defined inspection scope may not be directly comparable with one that includes specific project requirements.
Packaging is easy to forget during quotation comparison.
However, packaging may affect the final delivered cost.
For example, products may require protection against:
Surface damage
Scratches
Transportation impact
Ask:
What packaging is included in the quotation?
For larger or more complex enclosures, also confirm whether special protection or packaging requirements are necessary.
A lower unit price may not include the same shipping preparation as another quotation.
When comparing suppliers, use a table like this:
Item | Supplier A | Supplier B | Supplier C |
|---|---|---|---|
Material | |||
Sheet Thickness | |||
External Enclosure | |||
Internal Brackets | |||
Custom Openings | |||
Welding | |||
Surface Finish | |||
Hardware | |||
IP Requirement | |||
Inspection Scope | |||
Packaging | |||
Unit Price |
This approach helps you compare the actual manufacturing scope, not just three final numbers.
Imagine receiving these two quotations:
$180 per unit
The quotation includes:
External enclosure
Basic fabrication
Not included:
Internal brackets
Powder coating
Hardware
Special sealing requirements
$250 per unit
The quotation includes:
Complete enclosure structure
Internal mounting parts
Powder coating
Required hardware
Defined protection requirements
At first glance, Supplier A looks $70 cheaper.
But the two quotations are not for the same manufacturing scope.
The real question should be:
What will the final cost be to receive the complete product I actually need?
This is a much better way to compare suppliers.
Before placing an order, ask the supplier:
The final question is particularly important.
Sometimes a supplier's quotation is based on assumptions because some project information is unclear.
Understanding those assumptions before production can help avoid misunderstandings.
The best way to receive comparable quotations is to send all suppliers the same RFQ package.
Try to provide:
The same drawings
The same quantity
The same material requirements
The same thickness requirements
The same finish requirements
The same protection requirements
The same expected manufacturing scope
This gives each supplier the same starting point.
If one supplier suggests a different material or structural solution, ask them to explain why.
A different recommendation may be useful, but you should understand whether it changes:
Cost
Performance
Product requirements
before comparing it with the original specification.
Price is important.
But for a custom enclosure project, buyers should also consider:
Does the supplier understand what the product needs?
Can they clearly explain what is included?
Do they ask useful questions about unclear requirements?
Can they support the type of enclosure you are developing?
Can they provide the required parts and processes for the complete project?
A quotation is not just a price.
It is also an indication of how the supplier understands the project.
If a supplier immediately provides a very low price without asking questions about important missing information, buyers should consider whether the quotation is actually based on the complete requirement.
Different sheet metal enclosure quotations do not necessarily mean one supplier is simply expensive and another is simply cheap.
In many cases, the difference comes from what each supplier has included.
Before choosing a supplier, compare:
Material
Thickness
Complete enclosure scope
Internal structures
Openings
Welding
Finishing
Hardware
Protection requirements
Inspection and packaging
The goal is not just to find the lowest quoted number.
The goal is to understand which supplier is quoting the product you actually need.
A clear comparison before ordering can help reduce unexpected costs, specification misunderstandings, and project delays later.
The suppliers may not be quoting the same manufacturing scope. Check material, thickness, internal structures, openings, welding, finishing, hardware, protection requirements, and other included items.
Not necessarily. First confirm that all quotations cover the same product specifications and manufacturing scope.
The quotation should clearly identify the material, thickness, manufacturing scope, finishing, included components, quantity, and other important project requirements.
Yes. Internal mounting plates, brackets, support structures, and other components can increase both material usage and manufacturing requirements.
Yes. Protection requirements can affect enclosure design details, sealing structures, cable entries, and other manufacturing considerations.
Before choosing a supplier, make sure you are comparing the same manufacturing scope.
Send MT Metal your drawing or current quotation requirements, and we can review the project scope and clarify the key manufacturing details that should be defined before production.
