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Combination Square

Weld_

Aluminum
Joined
Mar 15, 2016
I'm in the market for a new combination square.

I have looked at Starrett, PEC, Brown and Sharpe.

I do primarily metal fabrication and welding.

Was wondering if the community could help me settle on a particular model.

I am looking for something with a 4R blade style.

I am looking for something between 12in and 18in.

I have a few questions they are as follows.

1. Should I get the hardened tool version considering I work primarily with metal?

2. I own older Starrett tools that are simply magnificent but I find some of the newer offerings not as good what are your thoughts on PEC along with Brown and Sharpe, of the three which one makes the better combination square?

3. I need something that is less susceptible to rust it seems that most of the higher-end combination squares are all susceptible to rust. I need recommendations in that department.

I am not brand loyalty any particular company so any suggestions outside of those three are also welcomed. However in this particular case have been leaning towards PEC.

Thanks in advance any and all help is greatly appreciated.
 
I am still using a Mitutoyo set that I bought new circa 1974. I have the 12" and 24" blades, which are satin chrome plated. It has proved to be a fine tool. I have picked up a number of used combination square components over the years. I advise you to not buy one with a bare carbon steel blade. They get rusty. I prefer the hardened 90/45 degree head. The protractor and centering heads do not get much use and do not need to be hard.

I have not bought a new square for decades, so I cannot comment on the quality of new tools from the makers you mentioned. For your metal fabrication and welding, I think a good used square would be a good choice.

Larry
 
For welding and metal fab. wouldnt a cheap set do?
Ive seen what welders do with precision tools.
I Am actually pretty good with my stuff. lol

What do you mean by cheap stuff, like a craftsman or empire or Johnson? those really don't cut it for me but if you know something other than that I am open to saving money. that is one of the reasons why I looked at PEC.
 
The hardened ones have an advantage if you're working light gauges. Sheet metal can wear a groove with lots of use.
 
I am still using a Mitutoyo set that I bought new circa 1974. I have the 12" and 24" blades, which are satin chrome plated. It has proved to be a fine tool. I have picked up a number of used combination square components over the years. I advise you to not buy one with a bare carbon steel blade. They get rusty. I prefer the hardened 90/45 degree head. The protractor and centering heads do not get much use and do not need to be hard.

I have not bought a new square for decades, so I cannot comment on the quality of new tools from the makers you mentioned. For your metal fabrication and welding, I think a good used square would be a good choice.

Larry

Larry thank you for contributing.
 
The hardened ones have an advantage if you're working light gauges. Sheet metal can wear a groove with lots of use.

That is a great point. what about rust resistance and the three brands that I mentioned? thank you.
 
For welding and general fabrication you can’t go wrong with one of the wide foot combo squares such as LaSquare, A New Wide Base Combination Square - Tool-Rank.com .
Mike
I am actually pretty familiar with the product. can honestly say I am not a big fan of it especially since the head is made out of aluminum will get nicks and dings fairly easy. it does have a stainless steel blade which is a big plus making the whole unit rust resistant.
 
That is a great point. what about rust resistance and the three brands that I mentioned? thank you.

You should've mentioned you were an underwater welder :D

Just keep them dry and they'll be fine. All steel bodied squares will rust if exposed to moisture or acidic conditions.
 
I haven't bought a Starret for a few years now, but they slide better than any other ones I have used. Do you need to set to 64s?
If they are going to get weld spatter get many cheaper ones.

I have a PEC double square that does not slide real smoothly, but I don't believe it is hardened.

Dave
 
I Am actually pretty good with my stuff. lol

What do you mean by cheap stuff, like a craftsman or empire or Johnson? those really don't cut it for me but if you know something other than that I am open to saving money. that is one of the reasons why I looked at PEC.

No offense intended, but our welder fab guy would destroy one in a shift.
 
You don't want one of the cheap squares, such as Empire. If it's sold in a big box or hardware store, you probably don't want it. Adjustment mechanisms are cheap, blades often machined with the groove a bit off, they're sometimes made with cast aluminum or soft cast iron heads, the adjustment may have plastic parts, the graduations aren't deeply engraved, etc.

Ditto the recommendations for a hardened head and a satin-chromed blade. I also have one stainless blade, but it's a bit soft and not especially well made.

I just went through the process of checking a large number of combo squares using a Taft-Pierce cylinder square and a squareness tester reading to .0001" One square was significantly off (a very old one) and one Lufkin (also older) was a bit off. Carefully hand grinding the groove seat got the Lufkin back to within what I could read -- I didn't bother on the oldest one. The others (Starrett, another Lufkin, smaller B&S, PEC and (surprisingly) a better-made Chinese set) were all within the limits of what I could check, no more than a tenth or two off in 8".

Starrett also makes a wonderful "builder's square" with hefty 18" or 24" blades and an integral protractor head; but it's so pricey you probably wouldn't want to use it for welding fabrication. Grab one, though, if you find one used and cheap.

I also checked some fixed squares -- all with hardned blades -- some with bevel edges (more for machining than fabrication) and others with plain blades (which is what you'd want).. You can get these in really large sizes, suitable for fabrication. Brands I tested included Starrett #20, B&S 540 and 542, Moore & Wright, a very nice Polish square, and a couple of cheaper imports (which met their spec). Even the Grade 2 squares check a bit better in most cases. There is also a newer square design made in both Germany and China which looks handy for fabrication with a ledge at the bottom. The one I checked (the German one) with a slight (.0001-.0002) bump where the base plate hits the rest of the blade. I'd still think that one -- maybe the cheaper Chinese ones -- in a 12" size would be handy for fabrication.

Having a couple sizes of fixed squares is a good complement to a combo square. The combo square depends upon both the central groove being machined right and two small patches where the blade rests (and slides) to maintain squareness. Not all that good when you're prepping welds with a grinder -- you're bound to get wear sliding a combo square head.

I've also had good luck with 18" and 24" satin chromed combo square blades bought as seconds (made in USA, but with the name ground off) and also gently used sets. The trick is having some way to check them when you buy them -- at the very least (for fabrication) scibing reversed lines and making sure they exactly match.

Anyhow, I'd be inclined to look for a used square, with a hardened head, protractor, and center head with both 12" and 18-24" satin chromed blades. A tiny double square (4" or 6") is also handy. Just be sure you have a way of checking them before putting into service. I'd also consider if a large fixed square might not be best for squaring up work.

If buying new, PEC is fine and a bit cheaper than Starrett/B&S/Mitutoyo. .
 
A lot has been said about rust. When my brother was working as a contractor he coated his tools with Future floor wax to prevent rust. When I was working in a testing laboratory we used Future to prevent our steel sample tubes with Future. Should work for squares and scales used in a welding shop.
 
For a welding shop, I would think that a 12" x 18" carpenters square would be just the ticket. Most of the weld departments I have frequented, do just that. I sure wouldn't use a precision tool.

JH
 
You should've mentioned you were an underwater welder :D

Just keep them dry and they'll be fine. All steel bodied squares will rust if exposed to moisture or acidic conditions.
I am not underwater welder LOL I know that if you keep them dry and put a little bit of oil ( not to mention constantly wiping stuff down with acetone) it will be fine but wipe down with acetone one time and leave it in the truck ( by mistake) and you got rust.
 
I haven't bought a Starret for a few years now, but they slide better than any other ones I have used. Do you need to set to 64s?
If they are going to get weld spatter get many cheaper ones.

I have a PEC double square that does not slide real smoothly, but I don't believe it is hardened.

Dave
I don't really need 64ths. As far as spatter goes there is really none with the tig process.
 
That is a great point. what about rust resistance and the three brands that I mentioned? thank you.

rust = occupational hazard. I've had Starttett and B&S and M&W as well as mitutoyo. All great. I've not had a pec. All will rust, well the Mit probably has an advantage with the satin finish.
 
You don't want one of the cheap squares, such as Empire. If it's sold in a big box or hardware store, you probably don't want it. Adjustment mechanisms are cheap, blades often machined with the groove a bit off, they're sometimes made with cast aluminum or soft cast iron heads, the adjustment may have plastic parts, the graduations aren't deeply engraved, etc.

Ditto the recommendations for a hardened head and a satin-chromed blade. I also have one stainless blade, but it's a bit soft and not especially well made.

I just went through the process of checking a large number of combo squares using a Taft-Pierce cylinder square and a squareness tester reading to .0001" One square was significantly off (a very old one) and one Lufkin (also older) was a bit off. Carefully hand grinding the groove seat got the Lufkin back to within what I could read -- I didn't bother on the oldest one. The others (Starrett, another Lufkin, smaller B&S, PEC and (surprisingly) a better-made Chinese set) were all within the limits of what I could check, no more than a tenth or two off in 8".

Starrett also makes a wonderful "builder's square" with hefty 18" or 24" blades and an integral protractor head; but it's so pricey you probably wouldn't want to use it for welding fabrication. Grab one, though, if you find one used and cheap.

I also checked some fixed squares -- all with hardned blades -- some with bevel edges (more for machining than fabrication) and others with plain blades (which is what you'd want).. You can get these in really large sizes, suitable for fabrication. Brands I tested included Starrett #20, B&S 540 and 542, Moore & Wright, a very nice Polish square, and a couple of cheaper imports (which met their spec). Even the Grade 2 squares check a bit better in most cases. There is also a newer square design made in both Germany and China which looks handy for fabrication with a ledge at the bottom. The one I checked (the German one) with a slight (.0001-.0002) bump where the base plate hits the rest of the blade. I'd still think that one -- maybe the cheaper Chinese ones -- in a 12" size would be handy for fabrication.

Having a couple sizes of fixed squares is a good complement to a combo square. The combo square depends upon both the central groove being machined right and two small patches where the blade rests (and slides) to maintain squareness. Not all that good when you're prepping welds with a grinder -- you're bound to get wear sliding a combo square head.

I've also had good luck with 18" and 24" satin chromed combo square blades bought as seconds (made in USA, but with the name ground off) and also gently used sets. The trick is having some way to check them when you buy them -- at the very least (for fabrication) scibing reversed lines and making sure they exactly match.

Anyhow, I'd be inclined to look for a used square, with a hardened head, protractor, and center head with both 12" and 18-24" satin chromed blades. A tiny double square (4" or 6") is also handy. Just be sure you have a way of checking them before putting into service. I'd also consider if a large fixed square might not be best for squaring up work.

If buying new, PEC is fine and a bit cheaper than Starrett/B&S/Mitutoyo. .
I really appreciate the time you took to write this up. thank you. So from what I gather Starrett/B&S/Mitutoyo are better than PEC according to you.
 








 
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