welcome back to steve rob reviews today we're going to explore why people break so many drill
bits i break drill bits too and we're going to explore the reasons why so many people break metal
cutting drill bits now i've learned all these things over the years from many different teachers
and you know what we all learn from each other and i'm here today to share what i know about drill
bits and how to prevent you becoming a person that breaks a drill bit especially in a spot that's
very critical and you didn't know why that drill bit just broke so let's go over and take a look at
the workbench here and i'm going to explore some reasons why drill bits break well here's the setup
right here and you know what i broke this drill bit it was my fault that i broke it but i knew
exactly why it broke and it was cutting through a hollow pipe like this we're going to go over
different styles of drill bits and why they break and just to say my favorite drill bits of all time
are cobalt drill bits now you can get whatever drill bits that you like but generally there's
various reasons why a drill bit would break and a lot of people break a lot of drill bits
and don't actually know why they break so many so today hopefully we can explore this
and resolve a lot of the mystery behind why so many drill bits are broken
in my experience the top three reasons why a drill bit breaks is because either the tip is
not sharp you're using the wrong rpm speed of the bit itself or you're not using enough lubricant
or i find like and i broke this drill bit itself was when you try to go through a hollow tube
it's very difficult sometimes to be absolutely perpendicular to your your hole so if you go a
little ways off like this and you start drilling well you're going to start to get it to bind here
and here and that's what happened in my particular case and that's just part of actually doing stuff
you will break drill bits the best thing to do is to actually be as accurate as you can
and try to make it exactly straight all the time but you know what in reality we just can't do it
so if we take a look at these drill bits here you can see the difference in lengths and you can see
the difference in diameter and the one thing you notice is a drill bit of this length here
why isn't this drill bit that long well there's a lot of engineering that goes in the drill
bits and they know that this drill bit at this particular line can only take so much torque
so as you increase the diameter of your drill bit
you can apply more torque so what's another reason why a lot of drill bits are broken well
in my experience a lot of people like to use pilot holes so they will drill a pilot hole first
and then well they take a drill bit and they try to finish it off but if you take a look right here
and you could see see well can you see the the drill bit in there that's hard to tell
but if you take a look at the reasoning behind this is this particular tip
is not engineered to actually drill through this plate only on the tip
because you will start to get chattering on your cutting edges here it's meant to cut
smoothly from here to here as it goes through the material now many times a lot of people are
going to say okay it's easier to do well yes it is but you do risk the possibility of breaking
your bit because the bit was never designed to have a pilot hole so generally i don't
use a pilot hole unless i have to you gotta be very careful on bits under one inch now you might
think that that's quite a bit you know a lot of people do use pilot holes but it depends on how
thick a material going through what the material you know thickness is and the and the material
itself and how hard it is and how good of a bit you have if you got like a four dollar
bit are you trying to drill through a 200 piece well you're better off to get yourself
a more expensive bit rather than get something stuck you know this far in now what do you do
so in reality yeah i kind of stay away from you know going the route of all these uh
pilot holes and this kind of stuff if you can't drill through it well you know what your bit needs
to be sharpened so what's another reason why a lot of times people are breaking their bits
well it's the lubricant a lot of times people don't use the right lubricant
they're just using motor oil they're using all kinds of different things but generally
i don't use any lubricant under uh you know 1 8 thickness and really there is no reason to do
it because you know you're not drilling through that long of a section right another thing is
a lot of people will take a drill bit say like this one here and they will put that
in their drill regular cordless drill or whatever now this particular drill
you could see the difference between the two here and we're just going to take a look
see if i can show this the best i can here the difference between the end of the flutes and the
end of the shaft so a lot of people what they will do is they will put this in their drill and put it
onto the flutes up here and what you end up doing is you end up snapping your bit here if it ever
does bind or grip it'll snap right in this section right here so you want to only put your your your
drill bit inside the retaining collar on the solid shaft not right at the end here that's
another reason why so let's go on to another reason why a lot of people break their drill bits
well as you can see here you're looking at the drill bit chart and it shows the
different materials and the different speeds and when you take a look at the different materials
not all materials require a lubricant and some actually specify not to have a lubricant
and if you take a look at the drill speed chart there you could see that yeah you're getting up
into high rpms the smaller the drill bit generally the faster the rpm so when you
get up into a one inch drill bit yeah you're not spinning that thing you know like 7000 rpm because
it's not designed for it and that's the main reason why i think a lot of people are busting
drill bits is because they're not actually using the right rpm and it's so easy just to go online
and only take like two minutes to google the rpm speed or print yourself out a chart like this
so you can just look it up and see what is the range now of course these are ideal ranges and you
know most people don't have them kind of speeds on different you know drill presses or your hand
drill but in reality yeah you really need to to be close to the ideal rpm range know if it should
have a lubricant use a half decent lubricant and majority of the time you will not break
your drill bit if you actually drill straight and that's the another key thing is straight
so as you can see by the chart yeah there's a big difference in you know the diameter of the drill
bit and the cutting speed and you know in reality most you'll never have access to the cutting speed
you know that they're requiring but take for instance this little pipe here this hollow tube
if you wanted to drill a hole between here and the other side and you have access to it well you
just use your square you just transfer it over to the other side and you'll have no problem
my situation was the part was welded on a piece of machinery and i had to the access was horrible
and i was off a little bit and she snapped right there so there's another reason why a lot of times
these drill bits will snap on you especially like i just use any material that says cutting
fluid and it works fine i just put it in this little container and squirt it in the hole
but there's one thing that causes a lot of drill bits to break even when you use cutting fluid is
when you have your flutes all filled up with cutting material a lot of people don't remove
it and i always just take an acid brush and just take it off and then start drilling some more
because if you don't you're cutting fluid inside and all your material here
well what happens is it binds up and it just causes a stress point right here now if you take
a look at these flutes you see like this is pretty thick here but if you take a look at the distance
you know and remove the material from one side to the other you're down to one quarter
of the diameter of your drill bit so yeah it will break you know in the flute area quite often
if you allow too much cutting material or fluid itself build up and it causes too much pressure
right in here so it's best just to use an acid brush and just you know wipe it all off and
then start over again now they do make cutting paste and i do use the cutting paste as well
and it almost looks like soldering flux kind of thing a little bit a little bit more dense than
soldering flux for plumbing and i find that is great in situations where you're drilling where
you're vertical and this stuff here regular liquid it you're drilling up how you're going
to get that liquid in there except coating your bit and then trying a bit at a time
so they do make some ideal pace that go on that are a lot more effective than cutting fluid itself
well i hope you found that informative i am not no way at all an expert on everything that has to do
with drill bits cutting fluid you know all the different processes involved in using metal
cutting drill bits but i like to just share what experiences that i've had over the years
and what works for me and hopefully you can pick up some tips that may help
you in the future as well we all learn from each other on youtube and i have hope i've
actually taught some people some good tips to follow so that they don't end up breaking more
drill bits than you absolutely have to so thanks for joining me here today if you've ever seen this
channel before you're welcome to subscribe come back for some more interesting subjects
cheers
you