Stefa CNC Sheet Metal Folder Fit: VHX, VHB or VH?

For a CNC sheet metal folder, the first decision is not automation level. It is whether the recurring part family needs alternating bend directions with automatic blank positioning, or whether it needs a positive-folding machine with the length, material, backgauge, and clearance envelope required by the profile.

That is the useful dividing line between Stefa VHX double folders and Stefa VHB or VH long folders. Roofing trim, gutters, architectural cladding, HVAC transitions, and OEM panels may all begin as flat blanks, but the right folder changes with bend direction, finished length, blank format, flange geometry, taper, material, and finished-part handling.

VHX fits repeatable parts with bends in both directions

The Stefa VHX is a double folder with positive and negative bending to +142 and -142 degrees. Automatic grippers position the blank through the programmed sequence. That makes VHX a strong candidate when recurring profiles require bends in both directions and manual blank reorientation is consuming cycle time or creating handling difficulty.

Published VHX models run from 3,200 mm through 8,400 mm working length and are listed at 2.0 mm maximum thickness in St40 steel. The machine uses front and rear backstops that support 90-degree bends up to 45 mm high, while the bending beams have up to 300 mm of retractable distance for additional bend clearance.

Those features matter only when the specific profile can remain controlled through its full bend sequence. A capacity table does not confirm clearance for a tall return, tightly spaced bends, a deep profile, a hem, or a part that cannot be released cleanly after the final bend.

VHX should lead the comparison when:

• Recurring parts require both positive and negative bends.
• The programmed bend sequence can retain the blank in the automatic grippers through multiple bends.
• The dominant blank lengths and materials fit the published envelope of the selected model.
• The profile clears the tools, grippers, backstops, and finished-part removal path at every bend.

For flashing packages, cladding returns, recurring trim profiles, HVAC components, and formed OEM panels, the attraction is not simply automatic movement. It is the ability to connect blank positioning and bend sequence when the part family is repeatable enough to support that workflow.

VHB and VH solve different long-folder problems

VHB and VH are positive-folding long-folder configurations, but they do not share the same published working-length, thickness, or backgauge envelope. That distinction should be settled before a quote is built.

The published VHB range covers 3,200 mm, 4,200 mm, 6,400 mm, and 8,400 mm working lengths. Depending on model, VHB is listed at 1.5 mm or 2.0 mm maximum thickness in St40 steel. Its published backgauge range is 5 mm through 1,250 mm, and its standard equipment list includes a two-axis backgauge for conical function.

The published VH range begins at 4,020 mm and extends through 12,060 mm working length. VH models are listed at 3.0 mm maximum thickness in St40 steel and a 1,100 mm maximum backgauge range. A fabricator needing the longer or heavier published envelope should not assume a VHB configuration provides it.

Put VHB forward when:

• Deep blank location matters for wide gutter bottoms, pans, fascia, or other broad profiles.
• Tapered work can use the published two-axis conical-backgauge function.
• Counterbending requires the access provided by VHB retractable trays.
• The recurring parts remain within the applicable VHB length and St40 steel capacity table.

Put VH forward when:

• The part family exceeds the published VHB working-length range.
• The required material envelope points to the published 3.0 mm St40 steel capacity.
• Long formed parts matter more than retaining a fully automatic positive-and-negative folding sequence.

Because VHB and VH are positive-folding configurations, profiles needing opposite-direction bends may require planned part reorientation between operations. That can be the correct tradeoff for long, variable, or lower-volume work. The real production question is whether the additional handling is acceptable once part length, operator access, staging space, and finished-part removal are considered.

Taper needs a drawing review, not a feature-list answer

Tapered gutters and architectural profiles are where broad machine claims can create expensive assumptions. VHB has a published two-axis backgauge for conical function. VHX supports tapered-part programming and collision checking. Neither capability alone confirms that a specific tapered part can be located consistently, folded without interference, and removed without damaging the finish.

For each tapered profile, I need the developed blank, finished dimensions at both ends, bend order, flange heights, return geometry, material details, and intended removal direction. That allows us to review backgauge movement, blank positioning, tool clearance, operator handoffs, and downstream stacking before the configuration is committed.

Material and part geometry belong in the same review

The Metal Construction Association identifies starting material format, thickness, panel profile, bend proximity, profile depth, surface condition, and fabrication-equipment limits as planning considerations for exterior cladding. Its fabrication guidance also connects profile geometry with finished-part nesting and material protection.

Those considerations apply directly to a folder quote. Coil gives a fabricator flexibility in finished length, but the resulting blank, profile depth, and handling plan still have to fit the folder and downstream process. A published St40 steel capacity should not be treated as approval for a different alloy, grade, temper, coating, blank width, or bend geometry.

Bring these items for the leading part families:

• Developed blank width and length, including the largest and most common blanks.
• Material type, actual thickness, alloy or grade when known, temper where applicable, and coating or finish requirements.
• Flat and finished-profile drawings showing bend angles, flange heights, returns, hems, notches, and tapered dimensions.
• The required bend sequence, including bends that must be positive or negative and points where the blank can be safely reoriented.
• Weekly production mix, lot sizes, changeover frequency, and profiles creating the most handling or quality difficulty.
• How blanks arrive at the folder and how completed profiles must be protected, nested, stacked, or transferred downstream.

Use acceptance parts to make the quote usable

Maximum length and material capacity are screening numbers. They are not acceptance criteria for the parts that will justify the investment. I recommend defining the quote-stage acceptance list around the profiles that actually govern machine fit:

• The longest blank and longest finished profile.
• The most demanding material within the intended production mix.
• The widest developed blank and deepest profile.
• The closest bend spacing, tallest return, smallest hem, and most demanding taper.
• The finish most vulnerable to marking or handling damage.
• The part that is hardest to remove, nest, stack, or transfer downstream.

Controls belong in the same plan. Confirm how each acceptance part will be identified in the control, who establishes the approved bend sequence, where an operator must reorient a blank, when long parts require additional handling support, and how completed profiles leave the machine. A control recipe is only useful when material staging, part orientation, clearance, and downstream handling match the programmed sequence.

Compare the difficult parts, not just the published capacities

Mac-Tech currently offers Stefa VH, VHB, and VHX folders. When comparing a long folder against a double folder, bring the drawings and materials that are difficult to fold, clear, or handle today.

I can help turn that information into a machine-envelope comparison, bend-sequence and clearance review, backgauge and gripper discussion, layout and handling review, control-recipe scope, and acceptance-part list for the quotation. The objective is to establish whether VHX, VHB, VH, or a different production sequence fits the work before the equipment specification is locked.

Related Video

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Sources

• Stefa VHX Double Folder
• Metal Construction Association, Best Practices for Use of Single Skin/Plate Metal for Exterior Cladding: Fabrication
• Mac-Tech — folders
• Mac-Tech — Stefa Brand Page
• Mac-Tech — long folders