Monday, November 11, 2019

How does a Yankee jam?

Had been browsing the online auction sites, something that can lead to an impulse buy. Perhaps this is also a subject that's in-line with the typosphere; vintage tools - another analogue, chip-less technology domain. So to add to the tool-chest I got delivered a very clean looking Yankee No 30A screwdriver.

These are of course very common, though not quite as common here as they are in North America. This specimen was manufactured by North Bros. in Philadelphia, made in the United States of America.

The subject of old tools is again a niche where the internet provides quite a lot of information - e.g. that Stanley purchased the North Bros. company in '46, so this screwdriver would pre-date that. It notes the '23 patent date for the improved ferrule and handle-mounting, so it's post '24.

An odd thing is that it is not nickel plated all over (or chrome plated, as it would be post '31). It's however mentioned online that during the war years, nickelling was abandoned to conserve materials and the parts were blackened or brushed brass. The steel (not brass) main tube was indeed originally blackened, traces remain, so that this particular screwdriver probably dates from '42 to '45 or so.

Another thing is that it's in very good condition, almost none of the usual dings and scratches. As if it was never used much, kept in a box or chest all the time. The wooden handle looks too good to be original in fact, as if it was re-finished at some time - most (all?) Yankee handles of the era are red. Then again, looking around the aforementioned auction site a bit, some handles seem to have been stained and lacquered like this.

When unlocking and testing the screwdriver, it worked beautifully and then suddenly would jam solid. Only after some 'knocking' would it come unstuck. Being curious what could be the cause and wanting a tool to be functional, took a look inside.

The brass sleeve can be slid off the ratchet mechanism, as is explained elsewhere on the net. Small screw removed, sleeve rotated to let the notch slide under the small 'bonnet' and it's off.

Playing with the mechanism exposed, no clues as to how or why it would jam. It still jammed, but certainly not on the ratchet gears. (Strange spiral marks on those ratchet collars by the way, can't imagine what wear-mechanism'd cause that. Could this be a tool-return scar during manufacture?)

Looking further, took a look at the one other possible point it could jam; the washer on the end of the spiral-shaft that keeps it in. So removing the end-screw (this is the No 30, the springless version, otherwise take care to extend it first...) the handle can be pulled off. This incidentally also makes clear that the tube indeed was originally blackened.

That holding washer is actually more of a malleable c-clip, that fits on a recessed bit of the shaft. It can be seen and accessed through the opening in the side of the tube. This clip should be tight, but here it was rattling quite loose. It was narrower than the recess for it too. Testing a bit, it turned out that this c-clip could tilt a little and then wedged itself tight inside the tube.

To remedy this, the tube on a wooden block, c-clip rotated in 'c' orientation and then given a few blows with a hammer (via another 'anvil-block'). This closed the open beak of the clip and made it tight on the shaft. Handle back on and screwed tight - and the screwdriver has not jammed again. So this probably was the cause of the jamming.

Unknown if this was a manufacturing fault or caused by someone having tampered with it more recently. (Perhaps when they took off the handle to re-finish it?)

Maybe it was an original fault - it happened on and off, so could've been missed in factory checks. That could also explain its near-new condition; as a temperamental tool it would have seen little use. Yet too expensive and functional to be discarded.

Even though the finish is unusual, the handle does look very 'credible'. The dimensions seem a bit off, the screw is recessed more than it should, but the seat is milled in the handle correctly. Maybe wartime new sub-contractors with small variations...

Not sure if the handle tube will be cosmetically blackened again. The brass tube shows no hints of ever having been blackened, maybe somebody once did a stellar polishing job or maybe it never was blackened at all. In any case, we may well leave it all as-is - with a bit of oil on the bare metal.

So still (or for the first time since '43?) a fully functional, usable ratchet spiral screwdriver.

In the tool-chest :)


  1. Nice screwdriver. I remember those from my childhood. I even had one that I never used when I was older. I never used it much. I have the push drill and have used that quite often. It still gets used. Much easier to grab than the electric drill.

    1. This is more of a 'gadget' than a tool for frequent use I think - does feel nice & solid though. Actually do use my geared hand-drill relatively often - indeed often easier than an electric :)