Straight edge hanging hole

[Jay Norton]

Is your question if it is hanging vertically would it stretch and affect accuracy or is it the hole will somehow distort the rule? If you're worried about it stretching, even aluminum has a modulus of roughly 250-280N. The force of gravity is a measly 9.8N and therefore would not be enough to even come close to elongating your rule in the slightest. You're more apt to lose accuracy by dropping it or letting your kid play with it

I was questioning if drilling the hole would distort the metal.

[Bill Dufour]

I was thinking cast iron camelback. For a simple steel flat bar. Not much effect.
BillD

[Warren Lake]

what I read think he said he hands camel back up to a certain weight then they put them somewhere special maybe on a plate or something as too heavy to be lifting. SO hanging is fine and wont be concerned. This was built from a shear blade then tool and die maker had it ground. Friend knew he was selling it went behind my back and bought it for my birthday.

[Greg Quenneville]

For precision straight edges the machinists are taught to support them on the airy or bessel points. The bessel points are .56 of the length apart, centered on the tool.

[Andrew Hughes]

I have 72 inch precision straight edge I bought from suburban tools. I keep it hanging from the hole in the heavy cardboard tube they sent it in.
My other straight edges are for wood and lay in well on my bench.

[Bill Dufour]

For precision straight edges the machinists are taught to support them on the airy or bessel points. The bessel points are .56 of the length apart, centered on the tool.

I knew a surface plate had airy points as does the support base. I did not know they were used for a straight edge.
Bill D

[Ole Anderson]

We are talking for woodworking use here and not NBS caliber stuff, right?

[Robert Hayward]

We are talking for woodworking use here and not NBS caliber stuff, right?

I sometimes wonder that same thing.

[Mel Fulks]

The main reason I made the 8 foot straight edge was to lay out an accurate sundial. Cast them from pewter and sold a bunch of them.
Even as kid I was fascinated by real sundials. I also have a North-South “noon mark” on the kitchen ceiling. Great instructive fun for kids
…of all ages. Done with mirrors ! There is a ridiculous number of non working sundials for sale.

[glenn bradley]

Mine have holes for hanging. I still did this.
Straight edge Storage (2).jpgStraight edge Storage (1).jpgStraight edge Storage (4).jpgStraight edge Storage (3).jpgStraight edge Storage (5).jpg
Just three pieces of elec conduit spares. Made sense for me since I already have cleat walls.

[Mike Cutler]

Drilling a hole is not going to affect it's accuracy.
I started my career working in a mechanical standards lab. I "calibrated" devices like straight edges, calipers, and such. In a lab, and machine shop environment, you will not find precision tools hanging from pegs and nails. They're almost always kept in wooden boxes, or drawers, for protection when not in use.
I have two Starrett 72" machine rules that lost their NIST Cert back in the 90's. They went from $700.00 precision tools, to 6' paint stirrers, when their paperwork was lost. They hang by holes drilled into the ends with the rest of my straight edges. My squares are a different story. They are very well protected when not in use. It's very easy to damage a square.

[Greg Quenneville]

In answer to the question about overkill for woodworking purposes:

My precision tools are for calibrating and adjusting my woodworking machines primarily. For the actual projects I have more appropriate tools.