How often do spring bars need to be replaced

Why would you need to replace the spring bars on the regular?  Unless you break one, there's no need to touch them.

My neighbor was working in the garden the other day, and claimed his watch fell off his wrist. Spring bar was nowhere to be found. It was an older watch, perhaps preventative maintenance could have avoided this.

I think they are meant to essentially last for a good part of the life of the watch strap, but as we all know anything mechanical will eventually need replacement or repair. Just keep an eye on them when you change your straps, and if they feel too loose for you, you can order them in bulk for cheap. I wouldn’t worry about them much, but the more exposure to dirt and water, the more likely they could get weaker and break.

There is a YouTuber I watch, WristwatchRevival, and he did a video with a watch in a similar situation-vintage watch that needed a service because the owner liked to use it no matter the activity, I believe they mention gardening.  I respect the owner for wanting to use the watch like their family member did in the past, but also there comes a time when you have to consider the age of the watch and if it is still worth it as the owner to risk wearing it in those situations.  But everyone has different ways of showing love and sentiment for their items and their past owners, so I still respect their decisions to wear the watches the way they do. 

Answer: Every time they fly across the room.

Nonsense, they only reach maximum reliability once corroded in place. 😂But seriously, my oldest watch is 35 years old, and I was wearing it every day for about 10 years, then in frequent rotation for another ten, and I still wear it off and on. None of my watches has had any springbar problems. That being said, I would consider springbars relatively sensitive to impact or other forms or mechanical stress.

I have had zero lifetime springbar failures myself. I have a feeling that NATO straps cause spring bars to fail, thus solving the problem that they themselves cause.

I’m willing to bed something else came loose, and that pushed the spring bar out and allowed it to Andy Dufresne into the garden.

My co-workers springbars on his SKX007 crapped out recently. 2011 watch that had occasional saltwater exposure and hard use. Replaced the mains and one in his clasp and all was good. 

Like a lot of things, they work until they don't. Most probably last the life of the watch.

The cheap spring bars that come with little tool kits are poor quality. The good ones have little collars near the tip for removal. 

Interesting hearing this. I'm a fan of Perlon straps, especially in the summer but curious about the effects it has on spring bars.

I just got into the vintage scene myself. Thinking I should just replace the spring bars for peace of mind. 

There may be some truth to that, because compression cycles wear springs, and not so much age. The more lateral movement a strap/bracelet allows the more it could age the spring bar.

Yet I have a feeling that many failures are due to a bad fit. Sure, the lug width is standard, but there is the question of diameter, both for the tips and the main body of the spring bar. The number of flanges, and the distance they will travel, as well as spring force, meaning how hard or easy it is to compress the springbar.

Ocasionally one will bend, or the little shoulders get worn down, or the guts get gunked or rusted up, but otherwise it it ain't broke, don't fix it. Did I miss any failure modes?

"...maximum reliability once corroded in place." 😂 Oh boy, have I struggled getting the spring bar out on a watch that has seen some serious wrist time. Even stabbed my thumb with the tool hard enough to draw blood several times trying to remove spring bars that had achieved "maximum reliability." 🤣

Amen.

I watched a guy on YouTube use dental floss to remove spring bars. His argument was the tool easily damages the watch and strap. 
He looped it around the end and pulled quickly. It worked.