Raised vs Flattened Expanded Metal: What Changes in the Production Line?

Flattened expanded metal needs a rolling stage after expansion. That extra stage can change dimensions, handling and the point at which you cut the final sheet. For a factory selling both raised and flattened mesh, the equipment decision starts with the finished product drawing.

When comparing expanded metal production equipment, define which products leave the line ready for sale and which need further processing. An expanding machine and a complete line for finished flattened sheets represent different supply scopes.

The Difference Starts With the Mesh Profile

An expanded metal machine cuts slits and opens the sheet into a connected mesh. In the raised form, the strands sit at an angle to the original sheet plane, giving the mesh a three-dimensional profile. Flattened mesh goes through additional rolling to bring that profile down. AMICO describes this secondary process in its flattened expanded metal guide.

Both forms still have strands and bonds, the junctions where strands meet. Flattening does not remove the strands or fill the openings. It changes their shape and orientation, which is why a drawing for raised mesh cannot automatically serve as the finished specification for flattened mesh.

Before choosing either route, inspect the component your customer actually makes. A raised panel intended for a frame may need a controlled profile and specified edges. A flattened panel may have to fit into a narrow channel. Those requirements affect the equipment discussion more directly than a broad application label such as “construction mesh.”

Flattening and leveling address different requirements. Conceptual illustration, not a machine layout.

Flattening and Leveling Need Separate Acceptance Criteria

Flattening concerns the mesh profile. The rollers compress the raised form toward the required finished section. Leveling concerns the shape of the sheet as a whole, such as whether it bows away from a reference surface. AMICO's published process describes leveling after flattening, illustrating why the two requirements should be discussed separately.

A sheet can retain its raised profile while meeting an agreed flatness requirement. Equally, a mesh described as flattened can still need a flatness check. Treat “flat mesh” as an incomplete purchasing description until the supplier knows which meaning you intend.

Ask for two entries in the technical proposal:

The required mesh form and finished thickness, with the measurement location defined.

The permitted sheet flatness deviation, with the reference surface, support condition and measuring method agreed.

Equipment names alone do not settle this. Suppliers may use “flattening,” “leveling” and “straightening” differently in translated quotations. Ask what each proposed unit does to your sample and which result it must achieve. Where a supplier proposes one unit for more than one purpose, have both results demonstrated on the same product.

This distinction also helps an existing producer investigate a complaint. If the customer rejects a panel because it rocks in a frame, first establish whether the problem is overall bow, uneven profile height or frame fit. Each question calls for different evidence. Ordering another machine before identifying the rejected characteristic can leave the original problem unresolved.

Specify Thickness and Openings at the Correct Stage

Keep Starting Thickness Separate From Finished Thickness

The thickness of the incoming sheet describes the raw material. Strand thickness describes the metal in a strand. Overall mesh thickness describes the depth occupied by the mesh profile. These measurements must have separate labels whenever they refer to different features or process stages.

For raised mesh, a caliper measurement across the complete profile is not the same as measuring the starting sheet. For flattened mesh, record the required thickness after rolling. Avoid a purchase specification containing only “2 mm expanded metal”: it leaves the supplier to guess which measurement matters.

For example, if a panel must fit a channel, the relevant check is its finished section at the mating area. The original sheet thickness remains necessary for selecting material and equipment, but it cannot replace the fit check. Supply the channel drawing or an approved sample along with the mesh drawing.

Mark Pitch and Clear Opening on the Drawing

LWD and SWD describe the long and short design dimensions of the pattern. LWO and SWO describe the corresponding clear openings. A pitch dimension and the empty space between strands are different quantities; a drawing should show the endpoints of each measurement. McNICHOLS' expanded metal catalog lists design size, opening size, strand dimensions and overall thickness separately.

For a flattened product, state whether the specified opening is measured before or after rolling. This matters when a purchaser sends a photo of a finished panel but dimensions copied from a raised-mesh catalog. Ask the purchaser to approve one finished drawing rather than letting two references define the same product differently.

Allow the Trial to Establish Dimensional Change

Rolling can change sheet dimensions and the mesh pattern. The direction of rolling is relevant: Niles Expanded Metals distinguishes rolling along the long and short pattern directions and describes elongation along the feed direction.

Use that as a reason to measure trial pieces, rather than adopting a universal percentage allowance. Record dimensions before and after rolling, identify the rolling direction and retain the material and pattern details. A result for one mesh is not an allowance for every product in the order book.

The same discipline applies to width. Ask whether a quoted machine width means incoming solid sheet width, mesh width entering the next machine or the usable width of the trimmed product. These are separate checkpoints in the route. A wide expanding machine does not by itself establish that the downstream rolling and cutting equipment can handle every mesh it produces.

Build the Route Around the Product You Sell

The two routes below are planning examples for finished sheets. They show the added process, not a standard DAPU equipment package. Material feeding, intermediate cuts, transfers and the exact position of leveling must be resolved for the proposed configuration.

Raised sheets: prepare and feed material → expand → level if required → finish cutting and edge work → inspect and stack.

Flattened sheets: prepare and feed material → expand → flatten → level if required → finish cutting and edge work → inspect and stack.

Conceptual routes for finished sheets. Intermediate cuts and transfers depend on the equipment and product.

Decide Where the Final Cut Belongs

Some equipment arrangements require sheets to be cut before they enter a separate flattening machine. That does not necessarily make the first cut the final sizing operation. If rolling changes the sheet dimensions, allow for the agreed finishing route and verify the size after that route is complete.

Bring edge requirements into this discussion early. A customer may want a specific outside size, closed diamonds at an edge, or a visually balanced pattern. Those requests can constrain each other. Brown-Campbell's expanded metal tolerance guidance treats sheet size, squareness and manufactured-to-size edges separately. Its numerical tolerances apply to its products; use an agreed specification for your own production.

The practical question for your trial is whether the proposed route can deliver the required dimensions and edge condition together. Inspect all four edges. A satisfactory center section does not show whether the final panel will fit its frame or leave acceptable cut ends.

Make Transfers Visible in the Quotation

A separate rolling machine introduces loading, unloading and temporary storage. Ask how each sheet moves between operations, who performs the transfer and how the mesh is supported. A quotation with three machine names can still omit the handling equipment needed to connect them.

For a linked arrangement, request a description of how material progresses through the line and what happens when one stage stops. For separate machines, establish batch size and where unfinished sheets will wait. The right choice depends on order quantities, product changes and available floor space. There is no need to force every mixed-product factory into the same arrangement.

Compare Finished Output Across the Whole Route

An expanded metal machine's strokes per minute describe the press cycle. A flattening machine may be described by a rolling speed. Neither figure alone tells you how many accepted sheets the complete route will deliver during a shift.

For a useful comparison, ask the supplier to run one defined product through every included stage. Count sheets that meet the agreed specification and record the elapsed time. State whether setup, loading, transfers, inspection and packing are included. This makes two proposals comparable without converting unrelated nameplate figures into a misleading output promise.

If the expanding stage works faster than downstream processing, establish where the extra mesh will wait and how much storage is available. If flattening is used only for part of the order mix, a separate unit may allow batches to be scheduled around other work. Check the actual workload before deciding that the lowest individual machine speed must always determine daily output.

Ask for a changeover demonstration as well as a steady run. Moving between a regular raised product and a flattened product can involve different tooling, settings, handling or inspection requirements. Have the supplier identify those changes for the proposed machines. The useful record is the full sequence and its observed duration, not an unqualified promise of a “quick change.”

When estimating cost, include the additional processing and handling actually needed for flattened sheets. Record labor, energy, consumables, inspection, rework and any outsourced operations on the same finished-product basis. Keep these project estimates separate from the purchase price of the main press.

Three Order Mixes That Lead to Different Decisions

The following are planning situations, not DAPU customer cases.

Suppose a building-material producer sells raised stock sheets but is asked to supply flattened infill panels. The first useful step is to obtain the panel drawing, quantity schedule and finish requirement. Only then can the producer compare outsourced flattening, a separate in-house unit and a more connected line.

That comparison should include who owns the quality checks between operations. If a subcontractor performs flattening, agree the incoming condition, finished dimensions, handling responsibility and rejection procedure. If processing moves in-house, those checks still need an owner. Buying the extra equipment transfers the work into the factory; it does not remove it.

Put the Acceptance Trial in Writing

Choose trial products from the range you intend to sell. Include the regular product and any other specification likely to challenge the proposed route. The thickest raw sheet is not automatically the only demanding product: width, material and mesh geometry also need consideration. Agree the trial selection with the technical team.

Separate checks for mesh form, sheet shape, finished size and edges.

Retain representative samples and record results against the same drawing. If a requirement is changed during the trial, revise the acceptance record so that purchasing, production and the end customer are working from one version.

Frequently Asked Questions

Can I Add Flattening Equipment to an Existing Expanded Metal Line?

Assess the actual mesh leaving the existing machine: material, profile, width, dimensions and output format. Then review the proposed flattening unit, transfer method, utilities and space. Confirm compatibility through a representative trial and an agreed supply scope. Matching the nominal widths of two machines is only one part of that review.

Does a Flattened Surface Mean the Edges Are Ready for Handling?

Inspect the edges separately. Rolling the mesh profile does not specify the result of subsequent cutting or edge finishing. Put acceptable cut ends and burr condition on the finished drawing, especially where people will handle the panel or where it contacts another component.

Can Raised and Flattened Sheets Use the Same Product Code?

Separate codes or clear condition suffixes make ordering and inspection easier. A warehouse should be able to distinguish the two without opening every bundle. Keep the drawing revision and agreed dimensions attached to each product, particularly where customers use similar catalog names for different finished specifications.

Can I Use One Sample to Approve Several Material Grades?

A sample demonstrates the material and conditions used to make it. Ask the technical team which additional trials are needed for other grades in your range. Include material identification in the trial report so that a successful run with one grade does not become an assumed approval for another.

Should Coating Be Included in the Production Line Quote?

Include it in the project scope if you sell coated finished mesh, and state whether the work will be performed in-house or externally. Agree the processing sequence and the condition in which the product is inspected. A quote for expanding and flattening equipment should identify separately any coating, curing, handling or packing operations needed afterward.

What Should I Send if I Only Have a Finished Mesh Sample?

Send clear views of both faces, a side view and the full panel with its orientation marked. Add any known material information, dimensions and end use. Arrange physical sample evaluation where photographs cannot resolve the section or material. Confirm a dimensioned drawing before approving the machine configuration.

Send DAPU your material specification, finished mesh drawing, required delivery form and target output. Identify whether dimensions apply before or after flattening so the equipment review covers the complete route to the product you intend to sell.