Drove off to work this morning and after 200 feet the driversside torsion bar snapped like a loud muffler explosion.
As a reminder, I installed the new set of 1" Just Suspension torsion bars just over a year ago.

Looking at the dark area at the broken part it tells me the crack must've been there for a while and it finally gave up.

Bad timing, but great time for an FirmFeel upgrade...

Glad you came through it okay. Wow! Have you checked out the Bergman torsion bars?

Just did. Only saw B & E-body torsion bars.

Luckily my car was already fairly low so the drop wasn't that much and I was able to drive around without much issues, other than slowing down for speedbumps and roadjoints.
Manage to go to work with just a small delay.

Yikes! Glad you made is out okay.

Like to hear member Molloy's take on those pictures. IIRC, he is a metallurgic engineer.

I've forwarded this to a metallurgist.

Below are 2 more pics I quickly took today.
I haven't examined the damage up close yet but I *think* the crack could have originated at/near a flat of the hex end.
Perhaps even at the parting line of the forge.

(It's the front of the bar that broke by the way. Driverside)

holy cow

I think I would've probably SHAT myself. Sucks being over seas like you are too, would make a great spear to toss through Just Suspensions front window....

Looks like crack/split started on center edge of one of the Hex Flats that starts the transition from flat to round.

bummer man. i went with MP units when they were still available because i was prefer OE QC vs aftermarket.

Well that rots! They sure look older than a year though? Not that it matters as they shouldn't break. Daily driver?

One year and one month. The car is a dailydriver.
Before I installed them I even gave them a coat of paint for protection.

Here's the entry on my site when I installed them;
http://www.bigblockmopar.nl/2013/11/1973-dodge-dart-1-torsion-bar-upgrade/

We did have our first night of freezing temps the day before, maybe they just couldn't handle the cold... lol

I do need to say the car sees a lot of speedbumps everyday here on my daily commutes. Most are fairly 'smooth ramped' speedbumps but I also encounter 3 concrete short curved bridges 2 or 4 times a day which have a ridge on the ramps that can be considered rough if you don't slow down enough.

Unless you are sliding over the speed bumps on your torsion bars they aren't the issue.

Wow! That's ugly!

I see classic fatigue features in the upper right portion, adjacent to the hex region, however, it looks like the fatigue is secondary to a pre existing defect.

Tortional loads will normally cause a spiral type fracture surface, and you sorta have that in the fatigue region (clean area). The long, flat (and dirty) area is very suspect. As was said, that's the older (and more significant) portion of the fracture. Maybe a lamination (or some other planar defect) in the steel from manufacture? Original sin?

Have to also say that pre existing defects (like large laminations) in wrought products is really rare these days, unless you're talking about material sourced from China or India - then all bets are off. But even they are raising the bar compared to some years ago.

If you clean the fracture in a good solvent with a non-metal bristle brush, you may be able to use the concentric beach marks and river patterns to locate an exact origin. Sorry for the fractography garbledegook. It's fairly intuitive.

Too bad you're not closer. If you clean it and take more photographs in macro-mode, I'd be happy to take a look. Or you could just buy new bars and move on with your life....

"I'm just a caveman, thawed out by your scientest", but here is my observations based on the photos.

It appears to be a fatigue fracture that initiated at multiple locations (Stage I-fracture initiation) shown my the red arrows, although these are only examples that can be verified by closer examination. The ratchet marks(white arrows) form as a result of multiple fracture planes and lends support to more than one fracture origin. The flat portion of the fracture (dark bracket) and, to some extent, the woody appearance of the fracture (dashed bracket) are a result of progressive crack advancement (Stage II- crack propogation). Final separation, or overload region, occurred in the cleaner-looking dull gray area that is shown as Stage III. Some evidence of beachmarks (blue arrows) indicate progressive crack growth before final separation (again, points to fatigue).

It is unclear if any material deficiency or pre-existing defects exists without looking at it closer.

I my past experience while driving in a 69 Dart with the torsion bars raising the front end quite a bit we experienced the same thing. That fracture had a classic torsional break of a round bar in a brittle material(spiraling fracture). However, that fracture had a tiny thumbnail near the origina (Stage II), and a rock ding at the fracture origin.

Bones break in a similar manner when torsionally loaded (see below), and you can recreate a torsional fracture using chalk or a crayon (also shown below) by twisting it in opposite directions just for fun.

torsional break on a bone.

crayon torsional break