why can't I drill a small hole? have a laugh on/at me

[MoreWellie]

has anyone tried to repair a cheap multi tool? I was shown the internals of a cheap multi tool that a friend has where an arm that is a press fit on a shaft has started moving which makes the tool useless.

Easy enough I said drill a small hole through the lot and put a pin in it

After an hour of drilling and trying different drills I have managed to get the centre of the hole just over a mm deep

I suspect the answer is going to be carp drills but I have used 4 different 1.5mm drills and one I tested on a bit of mild steel and it drilled through without any problem

They were unused as 1.5mm isn't a common size on the things I normally do but they were 2 from a screwfix tin set, a normal hss axminster set and the final one from a presto hss set

any suggestions for a different way of sorting the problem

you can see the little dimple (scratch) I managed to make on top of the collar

 

[Seadog]

It's probably a hardened part. Have you run a file across it to test it? If so, you'll need a carbide drill and lots of RPM to get through it.

 

[Arclikeharrypotter]

Decent cobalt I can recommend dormer a777

 

[Bobtail4x4]

are you drilling the correct way? ie clockwise??

 

[Richard.]

Cobalt might but if the part is a very hard material then even a 777 may struggle. I would say go with a carbide to be sure.
Bearing in mind I know nothing about that material your trying to drill but if for any reason it's work hardened from your drilling attempts then you should definitely look at carbide as even cobalt drills suffer badly once a material has worked very hard. It might not be a work hardening material but if it is you've likely made it harder.

 

[Richard.]

Use a cutting compound as well. They are not just useful to prolong the edges of your bits. Compounds help a lot with the actual cutting of the material.

 

[brightspark]

clean and Loctite on and its going nowhere

 

[Peloquin]

As has been said...carbide and cutting fluid. Steady pressure but don't hang off the drill.

 

[MoreWellie]

are you drilling the correct way? ie clockwise??

looking at the results I would tend to say I wasn't but as I haven't found reverse gear on my pillar drill I think I will have to say no

 

[MoreWellie]

clean and Loctite on and its going nowhere

excellent idea, thank you

easy to get too focussed on what you were doing and ignore other possibilities

 

[RichardM]

clean and Loctite on and its going nowhere

seconded

 

[MoreWellie]

Thought I might come back and finish this off. I could only move the bracket a small amount up and down so when I tried Loctite from both sides I wasn't confident how much had wicked in to the gap, left it for 12 hours, and when I tried the tool it came free fairly easily

Then the cobalt drill arrived and it was slow to get through the surface layer which had presumably hardened from all my previous attempts but once through that it drilled ok and I was able to pin the arm to the shaft and put it all together, job done

 

[Richard.]

Obviously some form of work hardening material. Either that or it's case hardened or something
You did well to get through the hard crust. Glad the job was successful.