I've been trying to find a 18"-24" precision straight edge for about $40 or less (delivered), and it's not easy to do. Typically, a 24" edge ground to 0.001" (really bad!) costs at least $50 before ship.

There's a pretty cool writeup here on making your own:

http://home.comcast.net/~jaswensen/m...ight_edge.html

As far as I know, the 1/4"x2" steel stock at e.g. Lowe's are hot rolled steel. A 6' piece, enough to make 3 2" edges as described here, would cost probably $15 or so, and a tube of lapping compound a few bucks more.

I'd guess that kind of steel stock should be accurate to within 0.002" over 2', guessing by the piece I have here and comparing it to other flat surfaces.

Any thoughts?

 

So did you follow through with the straight edge project?

I've lost mine or it grew legs and ran off...lol
I do have 2 pieces of stock that should be really close.


sp1

 

I cheated and got a 24" from Rockler that cost about $40.

To originate a straight edge, you need to start with three pieces of stock. Lapping just two together could leave you with an arc shape!