When Laying Out a Flat Pattern, Should a Hole's Position Account for Bend Deduction the Same Way Flange Lengths Do?

Yes. A hole's position on a flat pattern has to account for the same bend deduction that flange lengths use, because the flat pattern isn't a scaled-down copy of the formed part; it's the unrolled length of material that becomes that part once bent, and every dimension on it, including hole locations near a bend, shifts by the same math.

Why this isn't optional

Bend deduction exists because the material at a bend doesn't simply fold at a point. It stretches on the outside, compresses on the inside, and the overall developed length of the part comes out shorter than the sum of the two flange legs measured to their theoretical sharp corners. That's true whether you're dimensioning a flange edge or a hole fifteen millimeters from a bend line.

If a hole's position is calculated on the flat pattern as if the bend simply hinged at a mathematical line with zero deduction, the hole lands in the wrong spot once the part actually bends. The error is usually small per bend, but it's not zero, and on a part with a hole close to a bend, or with multiple bends between the reference edge and the hole, the error compounds.

Where this actually bites people

• CAD-generated flat patterns done right, manual layouts done wrong. Sheet metal CAD modules calculate bend deduction automatically and place holes correctly on the flat pattern because the hole's position is defined relative to the 3D formed model, not laid out by hand on the flattened sheet. Manual layout, or a flat pattern built without a proper sheet-metal feature tree, is where this mistake creeps in.
• DXF exports that lose the relationship. A DXF is just geometry: lines, arcs, hole centers. If the flat pattern that generated it already accounted for bend deduction correctly, the DXF is fine. If someone manually adjusted hole positions on a 2D flat layout without redoing the bend math, the DXF looks plausible and cuts a part with holes in the wrong place relative to the bend.
• Holes dimensioned from the wrong reference. A hole dimensioned from the far edge of a flange, on the far side of a bend from the datum, needs the bend deduction applied correctly in that direction. Get the direction of the correction backward and the error doubles instead of canceling out.

What to actually do

Model sheet metal parts in a CAD tool with a real sheet-metal feature set, one that tracks bend deduction (or an equivalent K-factor calculation) automatically and derives the flat pattern from the formed geometry.

Don't hand-adjust hole positions on an already-flattened DXF to "fix" a measurement. Fix the 3D model and re-flatten.

If you're checking a supplier's flat pattern before sending it out, verify that hole-to-bend distances on the flat pattern match what the formed part's drawing calls out once you account for the deduction, not the naive flange-length sum. A part that measures correctly flat and comes back wrong after forming almost always traces back to this exact step. DigiForge cuts and forms from STEP, STP, or DXF; a model with the bend math already correct is what turns into a part that matches the drawing.