KC Tool is good, but expensive. I’ve ordered direct from Amazon Germany or UK or from German tool shops when it was a big ticket purchase. But there is sometimes a long wait, where KC Tool will tell you if it’s in stock or not. In stock you’ll have within days, so sometimes it’s worth the premium.
XZN is metric. My suggestion is to do a little research to find out what you’ll need for common repairs and get those especially if you’re buying those German made bits you don’t want to buy full sets when you won’t use 75% of them. Pay attention to whether you need the short bit, mid length (4”) or long (6”). Tight clearances often mean one of those will work (in my case, an extension on a short bit or an open end wrench on a long bit would not work). At $20-25 ea. you don’t want to be buying full sets. Look at VIM, they make good economical options.
On my Audi, so far I’ve found a standard and mid length M8 and an ultra short and long M12 has covered my bases. But I’ve bought full sets of ultra short, short, mid and long bits from brands like OTC, Koken, Duralast (Taiwan) and gearwrench. Most of those sets were under $30 each, except the Koken.
Make sure you clean the head of the bolt and tap the bit socket in until it bottoms out. Keep it aligned with the bolt head and you’ll have no problems. If you don’t seat it properly or lean the bit over to one side, the probability of stripping the head goes way up. Once you strip it, it’s game over. So think about how the heck you’re going to get a drill in there as you’re leaning into the wrench. Like I said, do it right and you’ll have no problems.
