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The screws and nuts
that hold a saw handle onto its blade are getting to be either
hard to find, or are exceedingly expensive. The standard issue
nuts from the hardware store are simple plated steel, and are
not consistent in length in my experience. The brass split nuts
are available, but are limited in supply and quite expensive at
about $5 each plus shipping at the time of this writing.
I
thought to myself that I could make them almost as well using a
few simple tools found in most woodworking shops - and then I
would be able to claim that the saws I make are made entirely by
myself, something I thought would be kind of cool to be able to
do.
Materials and Tools Required
The split nuts
themselves will be manufacture from 10-24 (or 10-32) threaded
brass rod (1" long, from McMaster Carr) and plain 9/16" brass
rod (9/16" is a common size on most saws with split nuts, but
I've also seen 1/2" used), both available from good metal
suppliers online (such as McMaster Carr or MSC Direct). Tools
needed are a hacksaw, a drill press, a 10-24 (or 10-32) TPI tap,
a disk or belt sander, and finally a grinder outfitted with a
de-burring and buffing wheel. A jig for making the nuts will be
crafted out of some 8/4 ash, some 1/8" plate steel, and a
threaded insert.
To make the bolts, a
torch (along with all the necessary accoutrements) is necessary
for silver-soldering the nut to the threaded brass. An
oxy-acetylene torch is the best tool for this job - however,
here I am use one of those $50 welding kits that use a small
bottle each of MAPP and oxygen gas. These small kits supply
plenty of heat for the job, and are much less expensive than
buying a full oxy-acetylene rig. If you do a lot of soldering,
this is not very cost efficient method - but for occasional use,
they works fine.
You will also need
some silver solder and flux - I use a brand called "Stay-Silv
45" for the best results. This should be available at most good
welding supply stores.
A Simple Jig, and Making the "Tube"
What's needed first is
a way to drill a hole through the center of the brass rod in
order to thread the nut. The hole must be sized for the size
thread you want to tap, and centered in the rod to be proper.
The only way to do this is to build a simple jig to hold the
brass rod upright so the hole can be drilled into it's center.
You will see the jig in many of the following pictures here, and
I won't go into too much detail on it because of it's
simplicity.
Using a forstner bit
that's the size rod I am using, I drill a vertical hole into
some 8/4 ash, not all the way through, leaving about 1/2" of
wood at the bottom so the rod won't fall through. I then pick a
spot on it's side near the top and drill an additional 3/8" hole
from the side, centered on the previous hole. Into this hole I
insert a threaded insert - this will allow me to use a small
bolt to "lock" the brass rod in place, so it doesn't turn in the
hole while drilling it.
A small piece of steel
mounted on the side of the ash was added when the threaded
insert I used started wanting to strip out of the wood - the
steel is there simply to hold the threaded insert in place in
its hole.
Once the jig is
complete, I take a 7" or 8" section of brass rod, and insert it
into the jig. Using a center finder, I locate the center of the
rod and use a center punch on it to locate it for the drill bit.
I place the entire assembly on the drill press, and drill a
13/64" hole in the center of the brass rod to the drill bits
full depth:
Drilling it to the
full depth of the drill bit is necessary for the next step,
which is tapping the hole for 10-24 thread.
Making the Nut
The next step is to
tap the brass rod using a 10-24 tpi tap:
Tap to the full depth
of the tap - on subsequent nuts, it's occasionally necessary to
drill the center hole a little deeper to accommodate the tap.
Now its time to add
the slot for the nut - you can skip this step if the nut is to
be used for the bolts. I use a hack saw to make the slot:
Cut to a depth of
about 1/8" to 3/16" or so, making sure the cut is level across
the nut - then cut the nut off... |
