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Making spade drills

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Hi everyone,

Yesterday I made a spade drill for the first time following the instructions on the Chicago watchmaking school books, now I'm wondering if its possible to make a 0.10mm drill. Has anyone ever tried making one?

Thanks alot

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I've not, but I have seen a 0.3mm drill that was made to drill the hole in a collet for the hairspring on a verge pocket watch.

The drill is in the red square numbered '2'.

 

example parts numbered2.jpg

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I've made a 0.10mm spade in carbide for repivoting a small escape wheel pinion. Robert Porter wrote a nice pamphlet on making spade drills in steel or carbide with plans to make a simple indexing jig and a slightly modified pin vice which is available from AWCI.

A handy thing about spade drills is they can be ground "waisted" or narrowing from cutting edge back. In the event of breakage while drilling this makes it fairly easy to remove the broken drill from the hole.

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Thanks for the replies everyone.

Nickelsilver and Praezis, do you anneal the steel before making the drill? I'm trying to use blued steel, is it possible to make a drill from it or am I just wasting my time?

Thanks a lot everyone

 

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Thanks for the replies everyone.
Nickelsilver and Praezis, do you anneal the steel before making the drill? I'm trying to use blued steel, is it possible to make a drill from it or am I just wasting my time?
Thanks a lot everyone
 
Blue steel isn't hard enough to use for cutting steel. For a small drill start with O1 or similar tool steel. You can rough it out prior to heat treatment or not. Harden, then temper to a light straw color. Now you can grind the drill form, being very careful not to overheat and draw the temper further.

Carbide is handy for small drills as the heat issue disappears but you need very good diamond wheels and laps.

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I suggest buying them. 

Solid carbide sold in packs of ten, because you WILL break a few. Be careful because you can easily get a carbide “splinter” when the bit jams into your finger and snaps off...

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On 8/7/2018 at 11:08 AM, Tudor said:

I suggest buying them. 

Solid carbide sold in packs of ten, because you WILL break a few. Be careful because you can easily get a carbide “splinter” when the bit jams into your finger and snaps off...

Are you talking about carbide twist drills? 

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Here is how I make my custom drills:  http://jamesriser.com/Machinery/MakingCustomDrills/Spades.html

By starting with HHS I can skip the hardening process and possibly warping when using O-1.  I prefer to step down from a standard diameter to the required drill diameter.  This makes for a stronger drill and one easier to mount in the lathe or drill press.

Jim

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