Keys - Non-Ace was RE: ACE Key codes (xx2247 etc.)

Dennis Boone drb at
Sat Apr 23 11:04:18 CDT 2016

 > What do you think of the Klom imitation of it?

Initial impressions of the Klom K-747 tubular key cutter

The Klom K-747 cutter is designed to cut Chicago ACE type tubular
keys, and the Fort equivalents.  It is available in at least four
key barrel sizes, 7.0mm, 7.3mm, 7.5mm and 7.8mm.  The "common" size
seems to be 7.8mm, which is the inside dimension of the key barrel.
(In US measurements of such tools given in inches, it seems more
common to specify the O.D.)  The 7.8mm size is the appropriate one
for cutting e.g. DEC XX2247 keys.

Comparing the Klom to the drawings and photos of the HPC device in
the HPC manual, the Klom has some differences: more labeling than
the HPC, less projection of the cutter shaft out the back, and more
contact between the cutter knob and the depth knob at the bottom of
a cut, a rotating key shaft.  In the absence of a Klom manual, the
HPC manual is useful in interacting with the Klom version in spite
of the differences between the devices.

The design concept is straightforward and should be fairly easy to use.
The unit comes with a T-style key gauge, but no manual or 2.5mm hex
key for making adjustments.  The Klom unit provides spring and bearing
detents to help hold the key to the proper pin position and the depth
knob at the selected setting.  With a key inserted for cutting, the
device is about 5 inches long, and just under 2 inches in diameter.
Overall, construction seems sturdy.  The finish is black paint which
seems to scratch fairly easily.

The Klom design does not allow cutting of left or right offset keys.

Both the rotational position knob and the cutter depth arrived in
need of adjustment.  Both operations are obvious.  The rotational
adjustment is trivial, since the shaft on which the key mounts for
cutting has detents.  All one must do is turn the key to the first
position, then loosen the set screw in the knob to align the "1" on
the knob with the true line.  The depth calibration is not as easy,
since one must adjust the distance the cutter shaft is slid into the
device by loosening the set screw in the knob, pushing it in a whisker,
and tightening the set screw.  Since the designated difference between
cut depths is 0.016", this is fiddly.

Chicago ACE numbers pins clockwise from the 1 o'clock position
(looking into the lock).  Fort numbers pins counterclockwise from
the 11 o'clock position.  There is also a difference in pin depth
numbering between the two manufacturers.  The Klom unit matches the
Chicago scheme.  The HPC manual describes these numbering schemes,
and the information there applies to the Klom as well.  You will need
to understand these differences, as well as which variant was used to
specify the bitting you will use, to cut a usable key.  Both brands
have some numbering painted on their knobs.  It seems that it would
quite easy to paint full rotation and depth numbering for both Chicago
and Fort schemes on them, which would make using the devices easier
for novices, but neither does this.

There is a little bit of play in several places that could affect
accuracy: the depth knob rotates a large screw whose threads could be
tighter; the end cap that holds the key on the shaft can wobble enough
to shift the key side to side a wee bit.  The cutter shaft also has
more play than is probably necessary, but that won't affect depth.

Since this is a low-cost Chinese device one would expect a few issues,
and this device does present a few:

* Both sets of detents were a bit grouchy at first, as if there was
a bit of manufacturing debris inside, but seemed to settle down some
after a few minutes use.

* I managed to accidentally rotate the depth adjustment a couple of
times while making a cut.  The knob that turns the cutter meets the
depth adjustment knob at the bottom of the cut, and depending on how
hard you're pressing, friction between the two may be enough to cause
the problem.  Murphy is (as always) on hand to ensure that when the
knob moves, it goes toward a deeper setting, spoiling the key.  This is
a design issue that will have to be worked around by paying careful
attention during use.  It would be nice if the depth could be locked.
There are set screws to adjust the spring tension on the detents,
and I tightened them a little.  This helped some, but not enough.

* In my first attempts, I had some small variations in depth of cut
between different pins that were supposed to have the same value.
The above notes on play probably explain this.  Practice will help.
I haven't tested enough yet to opine on the impact in terms of marginal
or bad keys.

* It would be nice if the key gauge was labeled on both sides, since
when holding it in one hand and the key in the other, one uses it
face up for odd cut sizes and face down for evens.  (You could also
turn the key around, but it's easier to keep track of where you are
if you flip the gauge.)  I find the T-style gauge easier to use for
fine evaluation of depth, and the Southord style (key-shaped) gauge
faster for reading bittings from unknown keys.

I was unable to find the Klom cutter for sale in the US, and had to
order from China.  I ended up using  Delivery time was
nearly a month.  Listings also appear on aliexpress.


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