Bokum Boring Bars


Hello everybody Randy Richard in the
shop today we’re going to go over some tools from the Bokum Tool Company of
Detroit Michigan they’re Bokum Boring Bars if you’ve never seen one stick
around you’ll find out about it how you doing everybody Randy Richard in the
shop today we’re gonna go over some Bokum Boring Bars this is a long one
but they’re kind of unique they’re two-piece the cutter head unscrews from
the bar itself they’re sharp burnable they’re high speed steel there you have
a unique shape to them if you’ve never seen one before
we’ll do some close-ups of them and will sharpen them we’ll do it on a surface
grinder with some jigs I’ve acquired and we’ll go over to the lathe and we’ll do
some cutting with them they’re pretty unique if you’ve never seen one before
stick around and let’s go here to the service pipe behind me and we’ll go over
them and you’ll see what they’re all about
ok a Bokum Tool Company they’re up in Detroit Michigan they’re still making
tools and you can go online they have website and see their stuff anyway
it all started with me with this I got this from Don Kaas it passes on to me
and I never really looked into it too much but somebody showed one and I can’t
remember who it was but somebody showed one somewhere whether it’s on Instagram
or Facebook or something a video anyway and I made a comment that oh you know I
think I have one of those and this is a a B one
what it is is a sharpening jig for Bokum toolbar boring bars for the
smaller boring for the small smaller ones so that’s what it is anyway I made
it some comments and Dan Dobbs sent me instructions for one for this for this
one here and basically it’s the same instructions for all their jigs here
that I anyway so he sent me that for the instructions which thank you Dan this is
very helpful actually so that’s where it all started but I couldn’t have him
boring bars so Dan Dobbs there he he sent me some boring bars
this one is ends up being almost 11 inches and then these these are 5/16
shanks these are 3/8 shanks these are actually criterion ones but they’re made
basically the same way as Bokum and what’s unique about the Bokum is their
style of head-on they’re boring bar of how it’s how it’s been ground and these
are all one piece ones these larger ones are two-piece you have your bar and then
you have your head your cutting head which is pretty select your you know you
don’t have to replace your bar all the time so you know thanks to you again Dan
for sending these another fella Bryant oh he made some comments and sent me
some pictures and he asked some of these also he might have been the one I showed
it I can’t remember about in contact with both of these guys so since then
I’ve been on eBay and I picked up a couple of additional
heads here I’ll show all these closer this is for
like a grooving type tool internal groovy this is a standard one but it’s
carbide and I know it’s old it like this but I don’t think they knew did this
unscrewed this is a very short boring bar
but yeah so I broke them loose and and such but so those I picked up on eBay
and this is uh okay we’re gonna go over it but this is a style be one those are
basically brand new and I picked up this this sat here well those maker offer
things and when all the folks took my offer which was a sweet deal for me and it’s a very nice set of it’s not 100%
complete but it was a very nice set of boring bars and the this 516 shank ones
are size one and has do the head size these little ones here these are ones
it’s very small and then this is a – a little bit bigger I don’t have a three
but this is a this is for fours fives sixes sevens and eight and this one this
is a short one is short eight and this was a short short seven and then you
have your and then this is an adapter three quarter shank here for three
eighths or you can put a three eighths bar in there so what we got is there are
different styles a B and a C style head and we’re gonna zoom in here and show
you up close about all that we’ll talk that also what I picked up on eBay
was another sharpening Jig this one’s up quite a bit this goes in here this
one’s quite a bit larger and it’s a little different on how that one they
both work basically the same way it’s just how they’re set up it’s a little
bit different and this but this one’s really made for size for heads up to 12
I think they make them a lot bigger ones now I don’t have the instruction sheet
on this one but it’s basically the same as the the small one of how it works so
we’ll talk about we’ll talk about all that so let’s talk about the little one
first so this this here it’s talking about the little one cook over you lies
you this these are these jigs are designed to go on a surface grinder or a
tool and cutter grinder you could also do it but they talked about using them
on a surface grinder and you’re the this is the holder you put your boring bar in
there you know lock it down obviously and then you slip it in here this is a
three quarter shank then you have a little bar here which is for studying
your tool your boring head up against and you are going to be grinding this
right in this area of the surface grinder they has a diamond that comes
with it for surfacing your wheel for you know dressing the wheel and what you do
is basically is you come in you dress your wheel leave it that bad height and
just move over here and you’ve already set this and you come in at the
appropriate angle you’ve locked it down and you come in and grind that
and you have a new edge like I said like said you you have a continuous edge
going around here you have over 180 degrees on a new one that’s 210 or 20
degrees of angle that you’ll be able to grind and resharpen and this is a you
know down on the magnet flush up against the fence here and you just grind them
it’s a really pretty pretty easy method here now that holds 3/8 this is the one that
came with then I made one right here that I’m in another one that will hold
screw those in a little bit that will hold the 5/16 bars
now you can they say you can buy them in all different sizes 1/2 inch 5/16
quarter inch 12 millimeter 10 millimeter 8 millimeter that’s so I just made one
for 5/16 right now go in there hold the 5/16 bar was doing the same thing pretty
pretty simple pretty simple deal there and the big jig I mean it’s quite a bit
larger you know comparable eyz you know quite a bit larger it’s base here is
almost 9 by a little over 5 private quarter very nice they’re very nice to
me they’re all cast-iron this one came with the so that basically works the
same way but this is mounted on an angle and the different heads which will look
at mount against here I don’t know why they didn’t put a hole over here myself
too so you could swing this so it’s at 90 degrees like the small one there’s
the small ones Millie are 90 degrees I don’t know why they didn’t but anyway
I’ll probably end up doing that and you’ll see you’ll see why here as I go
through the different styles so really right now this is set for a B
type style anyway it has a diamond and like cities it has what it set out from
the surface plate or the base of this write-up you set that at that specific
height here this one’s 1.90 five inches this one’s one point two eight five the
small one and you lock that in place and you come in and you grind it
this one’s been hand ground and so it’s all messed up and this one we’re going
to grind as a demonstration so it comes with this one here these are adapters that go in this piece
and I have adapters here and these adapters there stepped for different
bars to sit in and sit on those steps I have no bars that fit in me and this
one this one’s a this one’s an 8 and it’s still too small for the smallest
step on that one but this this bar I have in here this
one here is a 7 and then the 8 also fits in this adapter here but this one also
and then the smaller ones one going this one here this one holds two sizes I have
this so this this one holds eight seven six I think it was and then this one’s
four and five you know floors fours go in there and then the 5 and then they
all they all fit and this holder here and then I I made one I also made one to
hold the 5/16 bars in here I’ll probably gonna make one to hold the 3/8 bars also ok so this is what we’re gonna be using
anyway that’s gonna that’s goes in there nice little hole to tighten it up with
and that goes in there and then you set it and lock it down and grind it came
with different screws and this different screws fit in here there’s a socket head
screws and they the heads have to go down here low enough so you don’t grind
the heads so some of them that dare turn down I ended up having to make
it was missing any or because of the size here for the six is I had I had to
make one I just turned the heads down to make them work that’s kind of nice it
you know it has the screws here screw holes here to hold all your screws to
hold your different heads on and then these other holes here I figured out
that they’re for Allen wrenches so we’re gonna look at these heads and this is a
six a a 6 B and we’ll grab a 7 C so here’s a an of B and the C just will get
them all framed together I guess see here the different styles like I said
this is a a B and a C and the a has a front rake angle on it here as it’s
going in for boring it’s also kind of rounded here they’ve they’ve taken a
little bit off of the nose and have a back rake here that clearance angle here
as a bar boring bar goes in they say this is kind of a finishing one I
believe this one here is flat across the front so if you need the flat bottom
hole or or shoulder you have this flat across the front and it also is a little
relieved on the nose so it has a kind of a radius here for a larger radius
cutting I think this one and this one I think is to finishing one this one was
like the roughing one but but anyway it has the flat across the front not this
angle here and then the c1 this is I’ve measured this this is actually 60
degrees you could actually cut threads with this and it has a it has a sharp
point you know it’s been formed to a sharp edge so you know you could bore
with it but also but mostly they talked about this one going in and being able
to chamfer on this edge here on the front of a hole and reaching around the
back and back chamfer without removing your part but we had over and cut that
they don’t really say it’s a threading tool but I don’t see your reason you
can’t thread with it so you could internal thread with it front and back
chamfering and then you have your other two so those those are basically the
three types and this one here now this what this one here is a is a B style
flat bottom but it’s card bite and so here you know it’s not carbide a
whole way or carbureted the whole thing the head’s high speed steel I think but
it has a carbide insert for not quote not quite 90 degrees oh when it was new
when it was new was probably about ninety degrees you can see here it goes
in ends right here yeah so this is all carbide so there’s a lot then there’s a
lot of a lot of boring bar left in this one but I’d have to use a silicon
cardboard or diamond wheel somebody’s ground this one a little tiny bit this
one here is also carbide quite large so the grooving tool setup you can see here
square or flat on the bottom or you the flat bottom a big hole but that’s quite
a bit here almost half an inch sticking out and not quite a quarter of an inch
width there now these these two here are these two these are both six bees or no
I’m sorry this is an a and this is a be I’m sorry Anna be and I touched these
ones up now already and they came out pretty nice this one was something that
you know touch with a hand grinded and so I needed a little it was wasn’t quite
the same as their hand grace I had to clean yeah anyway uh kind of sick waiter
sharpen things anyway we’re gonna go over to the grinder and little sharpen
sharpen uh that that’s seven one I have in there and show you how that works so
there’s a setup up here on the grinder now you have to put a 45 degree bevel on
your wheel and a flat and so far I’ve already done that but I did it a little
bit more than halfway so a little less than a quarter of an inch of flat you
know first thing first we need to put a 45 on the edge of the wheel and cuz I
don’t have one already set up we’ll be doing this 45 on them I’ll do it all right on the surface
plate here we need to set the height to the diamond and it’s engraved right here
one point 905 and that’s from the base here so I’ve already set my height gauge
at 1 905 and wood I already have it set there’s two set screws one on the side
to lock it and there’s one underneath one underneath here to adjust the height
which is kind of nice so what I did was I just hung it over the side here put
putting my allen wrench in the bottom and just barely had some tension on that
so it stays in position and brought my Heights gauge over until I just hear
barely touching scratching so we’re we’re all set on our height you go
over here set your set where you want to have the diamond and you dress
well you know we’re gonna do this so we’re gonna dress the wheel now we just leave the height that’s it
on your height and you bring here
let her down now this is kind of subjective but rotated up
basically just touches now this one’s been hanging around and
it’s kind of a tough shake so we’re gonna go through and grind it
and then and you have the tool up against that
stop with the way the stop is it matches the
angle on the boring bar head and you come up until that 45 just
touches the angle on the board lower already face way that sound and this
one’s been kind of messed with so it’s not quite right we’re going to take a
little bit off and you rotate it a little bit more
because it’s not right and tolls here for taking something I
find it nice just put down allen wrench in that hole
and give it a little tiny bit very controlled rotation so you just do it a
little bit you know take it out and they say to
strop it with a piece of wood there’s a very fine little burr but we’ll just you
can see where somebody hand-ground a little bit on that face on this one
they they touched it here and hand-ground it a little bit you can see
the air but it’s just minor I don’t think they actually that was the wood it
actually works quite well anyway nice nice finish draining and it’s a new tool
I need it ready to go and then the screwed in the center move that and it comes out you can see
where somebody else’s ground ground it right in here because they had the angle
quite a bit off anyway it it comes up very nice and that’s a nice boarding bar
head ready to go so that’s the operation and the small jig is the same way it’s
just this is at a different angle and you you still you do it all the same way
but it up against there you know set your height with the diamond and lock it
in and grind it all right we got the boring bar set up the one we just
sharpened so this is a h7 B and these these all have a hex hole broached in
them even though the screw passes through but just down to the hex and
that’s to tighten the boring head on the bar now one of their suggestions when
selecting what bar to use you have the centerline in your part or your whole
right and the centerline your bar well they want the bar diameter to be more
than half of the whole or half the rate you know I’d have to have the diameter
right more than that so they want this to extend past the centerline you know
over this side of the of your park so you know you don’t want to use a tiny
little boring bar where the whole boring bar is over here in in the in half of
the diameter you want it to be larger than half the diameter so you’re using a
bigger bar for a bigger hole all right that’s one of their suggestions and
that’s a probably a very good suggestion so well let’s uh let’s cut this around
9:50 ten thousands per Rev
let’s take 20,000 depakote this aluminum tube in there nice chip nice coil but still nice very
nice finished very very smooth very nice I think we have a successful sharpening
and very sharp tool you touch it very sharp now this has a fairly sharp point
you know it’s not like a rate too much of a radius on there fairly sharp so
it’s not gonna be a glass it’s not going to be the glass shiny finish I mean it’s
shiny but it’s very very smooth but you know you do have the slight machine
turning marks good but you know we use a larger will change over let’s try the
larger radius tool and see how it goes so to change this it’s just that simple
put a Helen wrench in there that’s what I had to grind quite a bit
since it had been hand ground pretty pretty bad and it really clean it up
still could use a little bit more and we’ll realign it to healing center let’s do the same speed same cut
actually now when I when I touched off I was
within mm of where the other tool touched off no all the way inside their smoother feeling finish yes I quite a
bit I can’t feel the machine marks or anything like that now very nice very
nice very sharp very very very sharp I mean yeah I like these boring bars and
especially we’ll see how they do it’s I’m going to maybe some softer steel
eventually here and a little addendum to the Bokum boring bars so this is a
number 11 I picked up on ebay love and B so the B is for flat bottom you know
boring to a shoulder or you know a blind hole type of thing this one was brand
new I took off the covering and one thing I want to note about the the bars
is that the proper grinding angle this angle here this angle here is through the
centerline of the bar so as its as a you grind this and where you’re always
grinding back to the centerline along the centerline and that’s critical
that’s what the jigs for is to maintain that angle to centerline you know you’re
holding it like this so this is basically parallel with the plate and
you’re coming in with your wheel and grinding this way but maintaining an
angle through the center line or center axis of the bar I just wanted to show
that but this is a really large one so I didn’t have a boring bar for it so this
is what I came up with now this is an odd size again but this is fourteen
threads per inch where the other ones are 20 threads per inch and an odd
diameter and so I mean a short bar here and then the boring head goes on this
end a little taper in there this is an inch
of quarter stock and I just put a little bit of taper in there to match the
smaller size of this and then this end I bored out I go to tapped three-quarter
ten and made a one inch piece of one inch stock a base for the bar my quick
change tool post boring bar holders has a one inch bore in it so this could go
right in the tool holder and I could build whatever length ones of these I
might want well maybe I’ll build a shorter one or
another longer or a longer one even but there you go built up boring bar from
the bulk of it yeah anyway this came out really really good this should work
really nice you guys enjoyed the Bochum boring bars I’ll be using these fairly
often I think they work really nice a very solid and nice finish
especially on softer stuff do you know but yeah very happy with that very happy
so thanks you guys thanks for watching please subscribe and support the channel
you know by a scribe by a dovetail cutter support the channel sure
appreciate it alright thanks you guys and thanks for
watching

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