What kind of fastener is this on this Lionel 4050 Transformer?

These were used to keep average Joe from opening the transformer, getting electrocuted and suing Lionel.  You found the right tool.  You can, probably, get it cheap and quick from Amazon.

Have you tried a flat blade screwdriver that fits the diagonal corners. I would think that would work. Maybe sacrifice an old beat up one that you used as a chisel a few too many times and grind it to fit.

Pete

George, ....if you’re going to be the end user, I’d do as Pete suggested, and then simply replace those tamper proof screws with a matching Phillips, torx, or whatever you’d like,.....I wouldn’t be bothered buying a bit unless I planned on opening up bunches of them,.....

Pat

@harmonyards posted:

George, ....if you’re going to be the end user, I’d do as Pete suggested, and then simply replace those tamper proof screws with a matching Phillips, torx, or whatever you’d like,.....I wouldn’t be bothered buying a bit unless I planned on opening up bunches of them,.....

Pat

But Pat!!! It's a tool!!!! I collect tools ... or so it would seem! I did stick a small sacrificial flat blade screwdriver down in there, with the intent of replacing the removed security screws, but they are in there tight and my thousand or so years of experience immediately told me the screwdriver blade was going to round out that hole really quick. Interestingly, I found references that pointed to this type of security bit being used from the 40's into the 60's, with a few applications in trailer window mounting into the late 70's.

Wow, I must be retired or just have a lot of time on my hands!

@GeoPeg posted:

But Pat!!! It's a tool!!!! I collect tools ... or so it would seem! I did stick a small sacrificial flat blade screwdriver down in there, with the intent of replacing the removed security screws, but they are in there tight and my thousand or so years of experience immediately told me the screwdriver blade was going to round out that hole really quick. Interestingly, I found references that pointed to this type of security bit being used from the 40's into the 60's, with a few applications in trailer window mounting into the late 70's.

Wow, I must be retired or just have a lot of time on my hands!

Then George, proceed with the upmost fun at hand!...😉 carry on, we’ll be in the area all day .....🤣🤣🤣

Pat

I believe it is called a Double D bit.

I picked up a security set similar to this Protorq set at an auto parts store. <$20

The torx bits with hole have helped me out often

George,

Those use a 1/8" Clutch bit.

A word of caution... the vast majority of those transformers were assembled with drive screws, meaning that they were intended to be a one-way operation. I've had some luck heating-up the screw with the tip of a soldering iron before the extraction attempt, but that can be hit-or-miss.

A few later transformers were assembled with true clutch screws, and those can be easily removed -- they were blackened. But the galvanized finish on yours tells me it's one of the drive screws.

Good luck!

TRW

@PaperTRW posted:

.. the vast majority of those transformers were assembled with drive screws, meaning that they were intended to be a one-way operation.

Yes, very steep threads with sharp self-tapping threads.

@PaperTRW posted:

George,

Those use a 1/8" Clutch bit.

A word of caution... the vast majority of those transformers were assembled with drive screws, meaning that they were intended to be a one-way operation. I've had some luck heating-up the screw with the tip of a soldering iron before the extraction attempt, but that can be hit-or-miss.

A few later transformers were assembled with true clutch screws, and those can be easily removed -- they were blackened. But the galvanized finish on yours tells me it's one of the drive screws.

Good luck!

TRW

Thank you, Todd! I had not thought they might be drive screws, that will change my approach to removal!

George would an EZ out extractor bit work for you?

@Rich Wiemann posted:

George would an EZ out extractor bit work for you?

Very possibly ... hadn't thought about that either! I will probably try that when I get my new surprise drill bits this Christmas! My easy-outs are new, but my drill bits got rern'd as they say around here. Seems my Drill Doctor either wore out, or I'm using it wrong - works on the bigger bits, but cuts a negative slope on the leading edge of all my smaller ones - they now cut like the back side of a spoon!!!

Just to put closure on this thread, I ordered a 1/8" clutch bit (and a 3/32" bit just to round out a set - I already had the larger ones) and easily removed the first drive screw, things got a little tougher as I twisted the head off on the second one, the third one broke the shaft but left some sticking out which I was able to get a hold of and finish the removal, and the 4th one broke off just below the plastic base. I was eventually able to remove all of them. Man, they are made of some seriously soft metal!!!

When I looked inside, the throttle shaft had cracked and half fell off with the Palnut still attached. There was just enough square portion of the shaft remaining to hold the wiper, apply a self threading screw and a large washer and epoxy the shaft, screw and washer together. Works like a charm! And who knew it had a small glass thermal breaker in there!?!? Reassembled with Phillips screws.

Worth the effort? Yeah, I just like to see how stuff is put together and make it work again!

George