Is It Okay to Model a Bend Relief as a Tear Relief on a Part That Gets Anodized or Painted?

Yes. A tear relief at a closed corner is fine on a part going to anodize or paint, as long as the flange geometry supports it in the first place. That's a geometry question, not a finish question.

Why the finish doesn't factor in

Anodizing and painting happen after forming, on a part that's already bent. The relief type is a decision you make at the flat-pattern stage, based on flange width, material, and bend radius relative to thickness. By the time the part goes into a coating line, the corner geometry is locked in. A tear relief that was sound before anodizing is still sound after. The coating adds a few microns of oxide or paint film, nothing that changes how a corner that's already torn in a controlled way behaves.

What anodizing and painting do change is how visible the tear is. A raw tear relief on bare aluminum reads as a small irregular opening. Dye can pool differently there than at a clean laser-cut relief, and paint can build up unevenly if the gap is tight. If the corner is cosmetic, that's worth weighing before you commit to tear over standard relief. It's an appearance call, though, not a strength one.

When a tear relief is the wrong choice regardless of finish

The real limits don't change with coating. A tear relief concentrates stress at a single point instead of spreading it across a radiused cutout. That's acceptable on a flange wide enough to carry the stress without the tear growing past the bend line, in a material ductile enough to keep the tear local. It stops being acceptable on a narrow flange, a tight inside radius for the thickness, or a material prone to crack propagation. None of that is about the finish. It's about whether the corner survives the bend itself.

If your CAD is giving you a choice between standard obround relief and tear relief at a closed corner, pick it using the same flange-width and radius math you'd use on an unpainted part. Decide the relief type for the forming operation first. Decide whether the resulting corner looks acceptable for the finish separately.

What to check before locking it in

Look at flange width on both sides of the corner relative to thickness. Check the inside bend radius against the alloy. If both check out, a tear relief at a closed corner is a normal production detail, finish or no finish. If the flange is marginal, fix the flange. Don't swap relief types to paper over it.

DigiForge's sheet metal line runs laser cutting, press-brake forming and PEM insertion, holding ±0.13 mm on the cut and ±0.5° on bend angle. Whatever relief you model carries through to the cut file exactly as drawn, so settle the geometry before you send it.