Where to buy flat metal bar for jigs.

[Deadeye]

Hi

I *was* after some 3/4" by 3/8" flat steel bar to fit in my table saw mitre slot for, y'know, reasons...

But then I wondered if it was possible to buy matching profiled bar (T slot but with wide base to the T).

I can't find anything that matches the T slot; and all the rectangular bar seems to worryingly equate "3/4 inch" with "20mm"!

Any pointers?

Also, if the primary properties I need are a) rigidity and b) constancy in temp/humidity/state of the moon changes (you'd be surprised how much this seems to affect everything else!), then is aluminium or steel better or doesn't it matter?

Thanks as always!

D

 

[marcros]

I have seen hardwood used, so aluminium will be fine. I use eBay for bits and pieces of aluminium and can usually get metric or imperial easily enough. Not checked steel though.

 

[Phil Pascoe]

I wonder if you could use two different sections epoxied together?

 

[CHJ]

one-stop-reference-links-t67853.html

There are some metal stockists listed in the General Metalworking forum links.
Metals4U etc.

 

[MusicMan]

Also, if the primary properties I need are a) rigidity and b) constancy in temp/humidity/state of the moon changes (you'd be surprised how much this seems to affect everything else!), then is aluminium or steel better or doesn't it matter?

Thanks as always!

D

For a given cross section,
1. Steel is about three times stiffer than aluminium.
2. Aluminum extrusion is usually a bit softer/weaker than mild steel, but this depends entirely on the alloy.
3. Aluminium alloys have around three times the thermal expansion coefficient of steels, so are less thermally stable.
4. Aluminium has much better thermal conductivity hence equilibrates faster
5. Neither is affected by humidity or the state of the moon or planets.

The differences are usually negligible in jigs for woodwork, unless you design something that is trying to match steel with aluminium, when you will make a nice bimetallic strip which bends as the temperature changes.

 

[Deadeye]

Great - thanks for the info.
Steel it is then.
Any clues on where to buy imperial bar rather than 20mm metric pretending to be imperial?

Thanks

 

[lurker]

I bought a cheapo plastic bread board from tesco , I think it was £2
This can be cut, drilled and routed just like wood, I even planed it with a block plane.

I made a batch of 8 t bars in less than an hour
IMHO these are better than metal

 

[powertools]

Cromwell tools sell ground flat stock in that size.
https://www.cromwell.co.uk/shop/materia ... l-/f/63520

 

[novocaine]

what is the table made from?
I'd rather the bar wore out than the table, so unless your table is harder than steel, stick with aluminium, the changes due to ambient temperature will be so marginally as to be ignored for the this application.

it can also be worked with a router although clamping it maybe awkward.