span of Presto-O-Lite key

[stumpstalker]

Questions:

1) What is the span of a Presto-O-Lite key?

2) and, they appear to be exactly square in photos; are they square?

Thank you.

[Mumbleypeg]

I believe the answers to your questions can be found in this old Knife World article posted in another thread here on AAPK. viewtopic.php?t=50466. Included in the article are the dimensions of the wrench hole, and the span of time when they were used. And yes, they are square.

Also dispelled is the common notion that these were "skate key wrenches".

(It should be noted that another square hole found on knives is that used by carpenters and painters to set older style mortise lock door hardware. The square holes in those blades fit the shaft to which door knobs were attached in those lock sets.) viewtopic.php?t=45209#p457508

Ken

[stumpstalker]

Mumbelypeg:

Thank you for those links.
The reason I asked this is that a 3/8 inch wrench appeared in a different field of collecting and it had an unknown application. The wrench, I now see, would be too large to be intended for a Prest-O-Lite tank.

In one of the linked Threads on Prest-O-Lite keys there is mention of other possibilities for the square opening (or, wrench) in the knife blade, i.e., mortise lock door; faucet and steam radiator shafts.

I live in an antique house and had all three shafts to check for viable wrench size, but was fresh out of Prest-O-Lite tanks for that final stage of the experiment.

9/32 inch seems to be about right for all three of the shafts that I tried out, but djknife13’s Ka-Bar Scout wrench blade in 3/16 inch would have been too small for them.


So, maybe the carpenter’s knives will turn a Prest-O-Lite valve -– with some play -- but a dedicated Prest-O-Lite key would be too small for the other applications discussed here.

Am always open to "peer review".

[TazmanTom18]

Prest-O-Lite tanks are still probably stocked at your local plumbing wholesaler. A call should locate one if you'd just like to check. A plumbers copper tubing cutter also has one in the pipe reamer built it.
Taz