Classic cars forum & vehicle restoration.

[ukdave2002]

Hi

I need to drill a case hardened shaft, any recommendations on the approach / type of drill? I don’t really want to use any heat. The holes don't need to be very accurate , looking on the web using masonry drill bits is one suggestion ?

Al advice welcome

Dave

[47Jag]

Dave,

I don't know what sizes they come in but there are special diamond bits for drilling ceramic tiles. May be worth investigating.

Art

[Uncle Alec]

I would have thought that a HSS cobalt bit, slow speed , and Rocol or sim drilling/tapping lube should do it.

[peter scott]

How about cutting a notch with an angle grinder first?

Peter
_________________
http://www.nostalgiatech.co.uk
1939 SS Jaguar 2 1/2 litre saloon

[PAUL BEAUMONT]

If you can find a local tool maker maybe you could have the holes spark erroded??
PAUL

[Ghost]

I go to model engineering exhibitions, just to gawp, my skills don't reach that far! But there are micro grain tungsten solid carbide drills for sale. Yes they are expensive, and no I don't have any, guess why! I would try one of these. Any decent model engineers supplier would advise on drill speed and lubricant too. Let us know how you get on.

[ukdave2002]

Thanks for all the advice The challenge in question concerned cross drilling the oil ways in a new layshaft I was making for the Morris 8 gear box. The original one had about 20 thou wear, and new ones are not available. Drilling the oil way through the length of the shaft was not a problem as its only the case that was hard. I had forgotten that the original shaft had "flats" where the oil holes were, so had to mill through the case hardened steel (rather than just drill). Normal milling bits just wouldn't touch it, so I ended buying a solid cobalt 8mm 3 flute mill and with some light cuts milled through the case hardening. I have never done any milling before so probably not the best job to start on ! ( it was a good excuse to buy a vertical slide for the lathe tho !)



Anyway it worked, the final drilling was the a straight forward job.



You can just make out the wear on the original shaft on the photo above.

Cheers again

Dave

[peter scott]

Very nice!

Proper engineering.

Peter
_________________
http://www.nostalgiatech.co.uk
1939 SS Jaguar 2 1/2 litre saloon

[Dodgealpine]

Glad you sorted it. One solution is to use a "Dremmel" or such like, using a grinding bit just to get through the hard case then you can drill it.