How to avoid a crank arm failing

Hello all...

Can I pick your brains please? Out for a good heart-pumping ride this week on my '98 Mantra and I had my left crank arm fail me with no warning (see the image below)

To my surprise, I didn't come off but 30 seconds before I was on a main road, and they'd still be shovelling my remains up now if it had failed then.

You'd like to think this is a one-off event but the thing is, I've had this happen before (with another Truvativ crank).

Any advice on the following would be great:

1: Where can I source a 175 mm square taper crank arm (ideally black) which I can actually trust? With no warning when riding, I need to know I have a crank that either won't fail, or give me plenty of warning that it is...

2: If I avoid an aluminium crank arm and get a steel jobbie instead (on the assumption I'd get more warning of the crank arm failing again), do you think it would up to the job? Any suggestions for a particular model would be most welcome.

I'd like to avoid Truvativ for the replacement - for obvious reasons - so that rules out SRAM stuff currently on the market too.

All advice gratefully received - Lack of confidence isn't an attribute normally applied to me, but after two close scrapes, I want to make sure I don't have a third unlucky scrape with the same issue!
 

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Re:

Holy crap! I assumed the bolt had come loose. That is crazy. I swear by Shimano. That being said I am running Race Face and White Industries on a few of my special rides.
 
Make sure you don't over tighten the pedal as this can lead stress cracking. Always use the correct torque settings.
 
Thanks for the feedback from you both - I'm assuming Alivio is the only range from Shimano I can get a new square taper crank. Hope it is up to my heavy-handed riding if I go that route!

As to the right torque, I will make extra certain for the new crank, but I don't think I've been overdoing things on that count...

Any more thoughts from anyone?
 

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