Huot index with 8 USA HSS Silver and Deming drill bits, 1/2" shank,
9/16 to 1". All new except 3/4", which is almost new. $12.05
Union Butterfield drill bit set, 1/64 to 1/2 by 1/64", TiN plated, in
huot index, all brand new, $10.
USA made drill bit set, small sizes about up to 1/4" by 0.001 or 0.002
(I do not understand the principle), looks like all others, $5.
Are you sure that is not a number size (wire size) drill set?
60 drills ranging from something like 0.040" for the #60 up to 0.228"
for the #1.
Don't expect them to be even sized steps. The sizes essentially
fill gaps left in the fractional inch sizes, so some skip over the
fractional in size. Also -- the size of the steps varies with the
overall size of the bit. For example, the #59 is 0.0410" and the #60 is
0.0400" -- so only 0.001" step size. But at the other end, the #1 is
0.2280" and the #2 is 0.2210" -- a step size of 0.007".
I believe that the sizes are related to the formation of wire by
drawing it through successively smaller holes -- with adjustments to
skip the fractional near misses. So you wind up with 0.1285" for a #30
and 0.1200" for a #31 -- skipping the 0.1250" for a 1/8".
Anyway -- don't expect the number sizes to fit a neat formula
for calculation. It is easier to implement a look-up table in your
Here are the sizes:
The number series actually goes on down to #80 (0.0135") in a
separate smaller index. If you have one of the 115 bit Huot indexes
(fractional, number, and letter sizes) you may have noticed a bent up
hook in the letter size section. It turns out that this is just right
to hold the index for the #61-#80 bits. (I discovered this almost by
accident -- never read about it anywhere, but wondered what it was for,
and since I had a Huot #61-#80 index, I tried it for fit and was quite
In which case -- *keep* it. Usually called "number size" or
"wire size" drills.
Those sizes are the best choices as the tap drills for many
smaller taps. I like having the fractional, number, letter, *and*
metric drill sets -- so between them you can usually find something just
the size you need -- including fine tuning the tap drill size when you
are tapping long threads in tough material. As long as there is enough
length to supply the strength when you have less percentage of thread
I've been damned annoyed by that hook for decades, in that it allows a
few drill bits to slide forward, preventing lifting the index on that
side until they've been slid back. Now I know!
Learn something new every day....
Yep! You grab the edge of the topmost letter tray in the
115-bit set and start to lift it, and it comes up about a quarter inch
or less and then pulls out of your grip -- until you tilt the index so
the letter drill side is down and the bits are no longer protruding
under the clip (he called it a hook) designed to hold the #61-#80 index
(sort of like a thick matchbook in size).
FWIW -- while the old HUOT drill indexes were gray hammertone,
and the newer ones are something like a fine-grained gray wrinkle
finish, the #61-#80 index from HUOT is blued steel -- or at least mine
Oh yes -- I also have an index for 3/4" to 1" Morse Taper 3
drills (a nice fit for my lathe's tailstock) which is olive drab -- and
the bits weigh enough so the pins on which the trays pivot tend to pop
out from time to time. :-)
I have three new Huot's for inch/number/letter purchased (empty) just
last year, but they don't have that "hook" piece. I have a Cleveland
and a few "Chinese clones of the Huot's" of the same type, and they
don't have it either. Funny thing is, I have about a dozen Huot boxes
altogether, and not one of them has what I would consider a "part
number" on them, so I have no reference to note.
In any case, I only have a few of the # 61-80's indexes, but none are
Huot that I could see, and I don't use anything in them often enough
to care about keeping them "convenient". In the smaller sizes, I keep
package size lots of just what I do use, including a goodly number of
the numbers and smaller inch, but none of the smaller letter drill
bits. I'm not good enough and don't care to learn how to sharpen the
itty-bitty stuff, and they are not expensive in package lots, so when
they quit cutting, they quit being drill-bits and become "pins".
It's the 3-in-1 box that has this hook. The hook is formed out of the
divider between fraction and number drills. I've wondered for many years
just what the heck it was there for. I assumed Huot didn't put it there
to annoy me, but couldn't divine any sensible purpose. I never thought
to try putting the small index in there. It does fit, and now it makes
Hey Jon (and DoN)
Hmmmm....I guess I just have different ones. These three have
fractions in three folding levels to the left, letters in three
folding levels to the right, and there is an upright divider between
them, and then the number drills are straight lined on the "lid" along
what I guess I'd call the "back" when it is open.
Found it on their site (called "Combination" indexes)
Have a look...no "hook" visible to me in the pix. Maybe they have
quit that extra piece?
It's there, just not exactly obvious. At the side of that divider, you
can see a light strip. It's punched on three sides and formed into an
'L'. This L is what we were calling the 'hook', and will hold the
miniature drill index. Maybe hook wasn't the best descriptive term...
Actually -- this photo *does* have it. Look in the divider near
the front edge. You will see a streak of lighter color bong perhaps 1/3
of the way along the divider. That is actually the bottom of the index,
seen through where the metal was bent to form the hook. The actual hook
will show up lower than we can see clearly in that photo.
It is formed from metal bent out of the divider into an 'L'
shape, with the open end towards the center of the box.
It looks sort of like this: (ASCII graphics -- use a fixed pitch
font like Courier to avoid image distortion)
| --------------Number--- \ ---Bits--------------------- |
| \ |
| Fractional bits \ Letter Bits |
| \ |
| \ <-- divider |
| \ \ |
| Hook for #61-80 index->\ \ |
| \/ \ |
Unfortunately, the '/' character does not make a true right
angle with the '' ones, so the hook is a bit distorted.
Interesting. My 115 piece set was purchased perhaps ten years
ago -- a "Made in USA" drill set from MSC with the HUOT index.
The hook is on the fractional drill side of the partition
between letter and fractional sections -- and close to the opening edge.
It lines up with the three largest fractional bit tips.
It is interesting that the index does not have the HUOT name
stamped in the lid -- that is blank. The only maker's mark is stamped
in the bottom - visible when the letter size drills are tipped up. And
yes, it *is* marked HUOT. (I've always wondered why the name is always
all upper case. Is it an acronym?)
I keep mine there less for convenience, and more as a way to
keep it where I can *find* it the few times I need it. The 115 bit
index is a lot easier to find than something as small as the 61-80
Yes, I used to keep it in a specific drawer of a machinist's
tool chest -- I forget who made that particular chest (if it even had a
maker's name visible), but it was not Gerstner. I do have a couple of
theirs, but this one is not it. (It does not have a hinged lid, so it
lives between two shelves a lot better than one with a hinged lid.
I happen to have a sharpener (which used to be made by DuMore)
which will handle 1/4" down to #70. Below #70, it is a mater of just
purchase new in packs of 12. :-)
If you are interested in what the sharpener is like, I made a
web page when I was getting it working.
I didn't have a Huot, but my index did that & was very irritating. So I
just left it open. But it was on a shelf and the sizes were hard to see
beyond the 1st row.
What I did was take the bit holders out, mount them side-by-side, just
above my drill press:
They are very conveniently located, I can see the sizes, and I can
extract & replace bits easily. None of which was true before.
I never could see the usefulness of boxed indexes - YMMV,
Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here.
All logos and trade names are the property of their respective owners.