On Feb 18, 6:32*pm, Grant Erwin wrote:
Grant Erwin wrote:
I have a 4" tube which I want to scribe lines on. The two lines will be
parallel to the tube axis and should be exactly 180 degrees apart, i.e.
on the opposite sides of the tube.

I know how to draw one line down a tube, but I am looking for a good trick
to locate the other line.

Ideas?

Grant

Got it, thanks. I was mitering a 45 degree cut, then rotating one piece
to make a 90 degree bend. All done, looks OK too (it's just for a barbecue).

Grant

I clamp angle iron to pipe with U bolts before making miter cuts.
There's no layout except marking the length because the angle squares
it in the saw vise, and I have flat clamping surfaces to align the
pieces for welding.

To attach a piece of angle at the other end parallel with the first
one I clamp a piece of bar stock on crosswise and level them both or
align them by eye.

Jim Wilkins