Geia sou, Vageli.

I found this thread after googling for 1605 runout. I happen to have 3 lengths of 750~800mm 1605s that show up to 1.3mm (!) of runout.

I put them on v-blocks and tried to apply force in the middle. I can bend them both by hand or by using a clamp (with a v groove on its plastic end). However, no matter how long I hold this position once I release them they spring back to their original shape.

I am leaving the clamp on one overnight to see if this helps. I am pushing down 0.8m (i.e. 0.15mm further down from the middle 0.65mm position).

I was wondering what did you eventually do with yours.

Cheer,
Elias