Aluminium or Steel Squares?

niemeyjt · 3 Feb 2021

Not sure about rules on naming products, so let's just say an e-mail arrived in my inbox from an American manufacturer doing special offers on their all aluminium (or should that be aluminum) squares. Browsing their site I see they also offer a variant with a stainless steel blade.

So, I just wondered about the pros and cons of each - and which style (not specifically maker) people prefer.

I hope I am not (re)starting a contentious topic! I did a search and I did find comment from Peter Defton and Custard in January 2018 suggesting weight may be one issue.

deema · 3 Feb 2021

Aluminium is soft easily damaged, you can’t run a knife down the edge with out risk of damaging it. IMO aluminium shouldn’t be used for any tooling, it always ends in tears

Tony Zaffuto · 4 Feb 2021

deema said:
Aluminium is soft easily damaged, you can’t run a knife down the edge with out risk of damaging it. IMO aluminium shouldn’t be used for any tooling, it always ends in tears

Your tears, stained red on whatever wood You were striking a line!

D_W · 4 Feb 2021

Steel. both for long term durability (lack of dents and cuts) as well as accuracy.

I don't know why, but some of the "precision" aluminum squares that I've seen aren't accurate out of the box. A friend here has a starrett certified square and didn't want to use it out in the open constantly and bought an incra certified square (I believe it came with a certificate or some guarantee - maybe it was called "guaranteed" square). Whatever it was, it wasn't close to its squareness spec and was far enough out to draw two lines and see that they weren't parallel.

I've seen other cheap aluminum or light alloy squares way out of square, when something is cheap, I guess the expectation is you can make it square.

Hardened head vintage combination squares are, in my mind, better than buying moderately priced fix squares. The reach is better on them and the older american hardened head combination squares usually have very little wear and work smoothly and lock up tight.

novocaine · 4 Feb 2021

it very much depends on the type of square and where it will be used.

something like one of those new fangled speed squares that has found popularity is fine being made of ali, it is never intended to be a precious or precision square (although I see plenty of youtube gods proclaiming them to be) it was aimed at a roofer joiner stuck up in the gods between rafters all day needing something quick and dirty mark and cut birdsmouths or ends with so has mutliple clever uses built in (taking a framing square up there being somewhat cumbersome)

my every day combination square (Again more used for site work than fine work) has an aluminium body, it's square enough for what I use it for and can be quickly repaired if I ever ding it. the Mitutoyo combination square (like Starrett only better) is all steel and is only ever used in the shop.

very much horses for courses.