Maybe because the screw was Phillips and the Milwaukee is Phillips, but the Euro and Jap drivers are, respectively, ISO and JIS?
JIS standard is apparently obsolete as of 2008 and I think PB Swiss (who claims to do JIS) and vessel now conform to DIN 5260-PH/ISO 8763-1
Someone mentioned that to me I think last year when I was talking about JIS screwdrivers. Lots of really fun information at this link below
Phillips vs. JIS (called "plus" in Japanese) vs. DIN 5260-PH/ISO 8763-1 Screwdrivers It seems that there is a lot of confusion regarding the various types of recessed cross-head screws and screwdrivers -- well, for me anyway! Most folks are aware that JIS (Japanese Industrial Standard)...
www.garagejournal.com
I contacted Tekton and I asked them what standards they were built to. And they did not have an answer and said... None.
I took this too mean that they simply contracted some company in the US that make screwdrivers and if I asked the actual manufacturer they would probably be more able to give me a definitive answer and it's just not anything Tekton ever thought about.
I think that one reason that the Milwaukee USA made grip so well is related to the coding that they have on the tip of their screwdriver.
Some of the Williams Phillips screwdrivers have serrations on the edges which I'm assuming are kind of digging into the screw, which is why those fit so well.
When I've tested screws in the past, at least Phillips, I found the tekton to mostly grip them pretty well. Most of the screws I was testing were relatively cheap screws and so I can't say for sure that they were manufactured well to tolerance of any sort. Well, the Robertson bits were really expensive and I specifically use them where it really matters what screw I use.
So I don't really hold it against the vessel that the pH1 didn't fit the screw well cuz this crew could have been garbage. And I only tested four screws one of each size.
Oh, and the only festival screwdrivers I tested were my megadors because those are the ones I have in my basement. I am more likely to be doing fine things while I'm in my basement and I really like the knurling on those megador vessels.
I also took a nice look at my older Craftsman professionals that I like so well and it looks like the PH2 driver s have had enough use. It's time to swap those out. Those are the last of my old Craftsman screwdrivers. I got rid of all the rest.
Not really related, but, some of the larger Tekton slotted screwdrivers are very smooth and I've never been convinced. That's a good thing. I prefer some kind of finish on the tip to help with gripping.