this is a set of cobalt step drills which were purchased from banggood.com
this set of five cobalt step drills actually cost about twelve pound fifty
including postage and packing so they were incredibly cheap it did take about
two weeks for them to arrive but that's to be expected as the are coming from
China so I thought I'd take a gamble and buy some of these just to test out
obviously step drills are normally very expensive so to get cobalt ones you
would expect these to be even more expensive I actually chose this set
because they actually have flats machined onto the end which does make them a lot
easier to grip in a standard chuck so they start and approximately 1/8 of an
inch and they go all the way up to one inch and three-eighths I couldn't
actually get a metric set the only thing to have imperial sets that have the
machined flats on the actual part that is gripped by the chuck the reason why I
bought these is to drill stainless steel so I've actually got a piece of
stainless underneath here which is approximately 1.4 millimeters thick so
we're gonna test these out I'm not going to test them all out but we'll just test
a couple out and see how well they do at drilling 316 stainless steel
of course before we do anything I'm gonna put a pair of safety glasses on
I'm then going to select a fast speed and we're going to test out the smallest
one first that starts at approximately 1/8 of an inch and goes up to half of an
inch whenever using a drill bit like this you will need some lubricant or
coolant so I'm just going to apply some of that to the tip there and that should
be transferred to the hole when we're drilling the stainless
I think you'll agree I went through the absolutely no problem at all
I'm now going to enlarge that using the next size up and I've already applied
some of the cutting paste to the edge there
I've now applied some more cutting paste I'm now gonna see if we can enlarge
it's a bit more
so as you can see we've got a hole through that stainless steel which is
well over inch in diameter and we got through there very quickly indeed but
I'm going to see just that long the drill bit lasts I'm going to drill a
series of holes in this stainless and we'll see if the performance of it is
impeded in anywhere
so I've actually drilled four holes with that one and it still actually looks
like a brand new step drill so the reason why I bought these because they
were incredibly cheap to be honest I would not have expected them to be as
good as they actually are I should point out that actually I did a set of three
of these but the actually sent a set of five instead by accident these do I
still like a quality made item I'm on one side of the step drill did they well
the sighs he's laser etched I'd like to thank you for watching this video if you
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