Is the thickness of the leather used for a vest a big deal? I found a 1.2mm one online and wanted to know if it's good.

 

Not really.

 

Not really because a vest doesn't really protect you. If you were talking jacket, gloves, or chaps, then leather thickness and grade matters.

 

If you like it, wear it.
I prefer this guy's stuff...
http://clubvest.com/t/mens-club-vests

 

If you like it buy it, 1.2mm of leather vest is more protection than a t-shirt. I would consider 1.2mm to be light weight leather. My vented leather jacket is around 1.4mm and my heavy leather jacket is 1.6-1.8mm just for comparison.

 

A properly design leather vest when buttoned or zipped up will help keep your chest warmer.

 

I meant in the event of a crash, such as sliding or impact, things of that nature.

 

Leather is good for road rash, sliding down the road, and to a lesser degree some impact protection. All other things being equal, thicker is better. If you're really worried about protection I'd think a good quality jacket would provide better coverage than a vest, your arms are not protected at all, (and if you are wearing regular jeans, they'll be ground away quickly in a slide). If it was me, I'd buy the vest without worrying about protection, to me they are more about the look.

 

Yeah, wear a jacket now, but temp is going up fast. Deep Deep South texas

 

I disagree with most answers here. Maybe the thickness isn't the best question, but the quality sure is. If you want your investment to last, and to last a long time, get good quality, which will typically mean a bit thicker. Best vest I ever had was 'Lil Joes, guaranteed for life. Made in the good ole USA.

http://liljoesleather.com/