Date registered: Sep 2004
Vehicle: 1985 500SEC, 1991 190E 2.6.
Location: Los Angeles / Hannover Germany
Mentioned: 11 Post(s)
Quoted: 1011 Post(s)
The bolt insert appears not to be T-30 anymore, and you can't really blame mechanics for not wanting to deal with the stubborn bolt at this point.
The craftsman bit you tried to use is likely made in China. Taiwan is a step up imo, as many top US brands contract (outsource) there.
There are bolt out kits available, that can be used with an impact driver (make sure its set to turn left), or an air gun.
Neiko 01138B 1/2 drive CroMo set used with a 26" breaker bar has yet to disappoint.
At apx $40 (set), I wouldn't be able to buy one same spec US made bit.
To avoid the edges to chip, it helps to clean the insert of debris to have the bit properly seated .
Hope this helps.