I agree that Sugino makes excellent products. I have been using their cranksets for over 35 years, and currently have five different bikes that use them, including a set of 75's on my track racer. However, nobody is perfect, and occasionally a defective part is made, even in the case of top line products. All manufacturer's have had these problems. It is not a condemnation of them, but simply a recognition that mistakes can be made. Based on what the OP has said, I think this is one of those cases. I have seen this type of failure in which the threads shear off completely at the base, and it is almost certainly a problem of faulty metallurgy and not human error.

I do not base my purchasing decisions on the personalities associated with companies, but on my own experiences with the product, including customer support when there is a problem. My experiences in this regard with Zipp were very bad, and I will never buy another Zipp product in my life. OTOH, my experiences with companies like Phil Wood have been excellent, and I will be a customer for life.

^Agreed, and this is why I think it might be worth it for the OP to take it up with Sugino. I'm not going to get into the debate of whether new track cranks are "worth" the investment, but I'm sure if I spent something north of $200, I'd expect it to last or for the company to stand behind the product if it didn't. All the nay-sayers aside, it sounds like the OP did everything right in this situation and the cranks failed. For any product, a small failure rate is inevitable, and it's how the company responds that counts. At that price, I'd say it's worth the price of a phone call or a letter; if you have pics of the fully stripped threads, Sugino might be compelled to help out. It boggles my mind that so many folks are quick to jump on the OP and insist it was user error -- I'm guessing in the interest of good customer service that Sugino will at least listen with a more open mind than that.

Yes, I'm not necessarily turned off by the quality of the crank; I feel like I must have gotten a lame pair or something, or perhaps a pair that wasn't fully finished in production. The crank puller cleaned out all of the threads to the bottom.

I was able to get the arm off with the 3 jawed balancer puller. Wasn't too tough and I was able to preserve the crank arm from a more destructive removal method (read angle grinder). I replaced the arms with another set of 75's that Ben's sold me on the cheap. If it's possible for me to be in touch with Sugino ab it, I have a fully intact, but stripped, drive side arm.

If you pulled out *all* the threads, that's just weird. I'd get in touch with Sugino. Sounds like a QC thing and should be under replacement or something.