Jigsaws have never really been made for presice and accurate 90 degree cuts, unless you are dealing with thin material. The thicker the material being cut gets, the more likely the blade is to wander from square.
Some jigsaws made within the past decade or so, and some higher end older jogsaws were better at square cuts, but even individual manufacturers were not always consistent with cut quality, and a newer model jigsaw in the lineup could easily be wirse than an older one.
Cheap jigsaws usually **** as far as square cuts go.
The best jigsaws as far as square cuts go tend to be pricey.
The current Mafell jigsaw is probably considered the current best model available.
It costs more than $500 in the USA, plus extra for some accessories you might want.
It can also take special, extra thick blades, that help keep cuts square, but it can also use regular T-Shank blades.
The Festool Tripn is another good jigsaw.
The Festool jigsaws have side blade guides designed to keep the blade square.
The Trion is an older Festool model that Festool was going to discontinue, but which they didn’t, possibly because the newer Carvex model meant to replace it wasn’t as sturdy a design.
Festool also makes slightly thicker blades for cutting thicker material, but the blades aren’t as thick as the Mafell blades. The blades are somewhat more affordable though, and way more readily available.
The saw was really only designed for carpentry work though, so the shoe is plastic, and tends to get torn up is you use the saw on metal.
The Festool Carvex should be able to do square cuts, but a bunch of the jigsaws seemed to have problems, either from the start, or after a certain amount of use.
The Carvex design doesn’t seem as robust as the older Trion saw.
The main advantage to the Carvex is that it has way better ergonomics, and a bunch of more versatile accessories.
It’s also available in a cordless model.
It’s been a while since I’ve checked, so I fon’t know whether the issues have been fixed yet.
Bosch tends to do very good jigsaws, at least as far as their higher end jigsaws go.
These models were either Swiss or maybe German made, and before that USA made, at least for the US market.
The flagship Bosch jigsaws use a guide system to keep the blades square, similar in idea to Festool, but made differently, and easier and kess of a hassle to use.
Someone above mentioned the older Bosch jogsaw that was considered the top of the line model, and one of the top jogsaws at the time.
The current top of the line models appear to be the JS572EK and EBK models. If you considered a Bosch, I wouldn’t recommend purchasing any oc the cheaper models for heavy work.
The Bosch jigsaws seem to get hot in the gearbox, and also leak a little oil, but it foesn’t seem to affect their cutting performance or longevity.
Hilti used to make a Jigsaw model WSJ850.
I never used one, but it had a very good reputation, and some people considered it one of the best jigsaws at the time.
Since then the newer Hilti Jigsaws seem to have less features, and cost less, so I don’t know they would be as well made.
One major issue for jigsaws and precision 90 degree cuts may actually be the roller behind the blade that is designed to support the blade.
If you try to push the saw too much into the cut, the roller can cause the blades to twist off to one side or the other, leading to innacurate cuts.
The pinch guides on the Trion sort of make this less of an issue.
The design of the guide on the flagship Bosch model seems to avoid this as well.
The Mafell jigsaw has no side guides or back rollers, and seems to rely on a very well made plunge mechanism and orbital design, so this isn’t an issue.
The other issue that comes up for cutting straight with jigsaws is the current trend towards quick tooless nlade change mechanisms.
Some of the blade lcks twist or rotate the blades into the locked position, and a bunch of companies seem to have completely screwed up on the engineering on the blade lock mechanisms.
The Festool Trions nlade lock works excellently, and keep the blade aligned properly.
The Carvex design may have had an issue with this, that vould skew the nlade slightly.
Some older German/Czech made Molwaukee designs used a quick change mechanism that really needed to be lubricated with grease or oil, and still needed to be checked for alignment, because it could lock the blade at an angle.
Older jigsaws that used a screw and clamp usually didn’t have these issues, you just needed to purchase some extra hex wrenches in case you dropped the one that came with the saw.
As far as blades go, Bosch blades are probably considered Top of the line.
Bosch not only makes the nlades they sell under their own name, they also likely manufacture most if not all of the other “Swiss Made” jigsaw blades you might see, including ones branded for Skil, Milwaukee, Makita, Vermont America, etc.
Otherwise ther are a couple German Jigsaw blade manufacturers, Wilpu and MPS Sagen.
One ir both likely make the jigsaw blades sold under the Festool brand name, as well as others. The Spyder jigsaw blades that lowes had were likely made by one of these German companies, maybe MPS.
Lennox still makes Jigsaw blades, and at least for metal, the jigsaw nlades have a good reputation. I believe the Lennox blades were made in the USA.
I’m not sure about Dewalt blades.
I’ve used Dewalt blades in the past without issue, but the nlades dometimes seem to be made in the USA, and may be rebrands of Zlennox, since Lennox is now oart of Stanley Black and Decker which owns Dewalt.
Other tomes the Dewalt blades I’ve seen are made in Germany. I don’t know if Black and Decker owns their own tooling manufacturer in Getmany, or whether the blades come from one of the above German companies.
There was a French manufacturer called Ultra that made quality jigsaw and hacksaw blades.
You used to be able to find the blades on Ebay, but I yhink the company went out of business, and the brand may have been sold to someone in India, so I’m not sure the current status.
Eclipse in the UK was a high quality British manufacturer of jigsaw nlades, but I’m not sure whether the nlades and still made in the UK, and what the current quality level would be.
Starrett also makes jigsaw blades, incliding some specialty patterns for woodworkers.
I don’t think the current blades are made in the USA, slthough older ones were.
I think currently they may be made in Brazil, but I’m not sure.
Don't see them on amazon for the US market though... Mafell brand stuff...