The only time that should happen is if the spring bars are too small for the holes., or the bars are of bad quality.

Most standard bars are 1.5mm to 1.78mm, but "fat" bars are 2.5mm so make sure the correct sized bars correspond to the hole size.

 

I think, more importantly, you need to try to fit the spring bar tips to the hole size. Not only do the spring bars come in sizes (as noted by Nokie) but also different size tips. When buying quality spring bars, you will usually have the option of selecting the tip size which are available in a variety of sizes. The common ones are 0.6mm up to about 1.1mm.
I have, on occasion, contacted the watch manufacturer to ask the size of the lug hole. You just want to get as close as possible without going over.
As for the spring bar ends causing the hole to enlarge, I don't buy it.
I hope this helps.

Bill

 

I recently bought a BNIB Seiko SRP231 that uses fat seiko spring bars. The watch comes on an OEM Z22 strap.

Even when brand new, the strap "clicks" a bit when applying pressure on the lugs. I feel it is the spring bar that slightly bends and clicks in the process.I even tried to check if it is loose by removing the strap and trying the same test. It was sturdy and didn't move within the lugs, the clicking noise came from inside the springbar itself as I suspected.

S.

 

you mean something like this ?

Means you are using wrong springbar.

 

I've had the click happen on both my monster and sumo, replaced them with 1.2mm ended springbars that fit perfectly even though the lugs are spec'd to be 1.1mm. The OEM springbars were 1.1mm but had a tiny bit of play caused by the tips being on a slight shoulder where connected to the rest of the springbar, force on the bar causes the tip to slide a tiny bit and the shoulder to jump up and click.

I wouldn't worry too much unless there is noticeable wobble and/or your case is made of a very soft metal like brass. Otherwise it's just annoying and any serious damage would require decades to show up.

 

Thanks for the tip! Gonna look for some 1.2mm ended springbars for my sumo. Worn on a NATO, it clicks whenever I bend my wrist.