Drilling high speed steel

[ianedge]

I have managed to get hold of a broken power hacksaw blade made of hardened high speed steel and was hoping to make myself a parting tool but none of the drill bits I have will touch it, does anyone know what type of drill bit I should be looking for

 

[paul-c]

hi
i have done the same thing - the best parting tool i have - its so thin and cuts so easily.
as its hardened steel you will need to use a dremel or similar with a small grinding stone.
just like sharpening a drill bit, the grinder just cuts no problem.
just be careful when you break through , i turned the blade over and then came at it that way rather than straight through from one side.
if you decide to carry on from one side make sure you open the hole up with a fair bit of clearance so the grindstone is unable to jam and possibly shatter.
best of luck
paul

 

[Spindle]

Hi

A carbide tile drill as supplied by all the 'sheds' will do it - lube with a little three in one oil or similar and go easy on the feed rate

Regards Mick

 

[chipmunk]

+1 for spear-point carbide tile drills.

If you want bigger holes than say 4-5mm then use more than one bit if you can, gradually increasing the size from small to large.
This should result in an easier and cleaner hole and faster in the long run.

HTH
Jon

 

[ianedge]

hi
i have done the same thing - the best parting tool i have - its so thin and cuts so easily.
as its hardened steel you will need to use a dremel or similar with a small grinding stone.
just like sharpening a drill bit, the grinder just cuts no problem.
just be careful when you break through , i turned the blade over and then came at it that way rather than straight through from one side.
if you decide to carry on from one side make sure you open the hole up with a fair bit of clearance so the grindstone is unable to jam and possibly shatter.
best of luck
paul

Thanks Paul I gave it a try after my tea and it worked a treat, not very accurate but that could be my ham fists It did the job though so now I have a tidy home made parting tool nice and cheap, thanks

 

[-Matt-]

Little confused here, as I've drilled sawblades before... and have done none of the above and been fine?
Standard HSS twisty bit, drilled like any other metal.

 

[woodiedonald]

The main body of a circular saw blade is mild steel or something similar, only the teeth are tungsten carbide (hard stuff).

Cheers,
Donald.

 

[KimG]

Little confused here, as I've drilled sawblades before... and have done none of the above and been fine?
Standard HSS twisty bit, drilled like any other metal.

These are the big 1"+ deep industrial hacksaw blades that are under discussion here Matt, they are HSS right through (otherwise they wouldn't be much use as a turning tool) and as such are equally as hard as HSS drill bits, so while you may eventually get through one, it would be more by a process of wear than actual cutting. You can get Cobalt drill bits that are harder, but they don't cut the HSS very well at all.

 

[AndyT]

I thought I remembered a discussion where someone suggested getting the bit of the blade where the hole was wanted red hot, to change its temper and soften it. They did this by abrading it with a blunt drill first, to get local heating by friction.
However, I can't find that so it may be just my dodgy memory. But while looking for it, I did find this thread which seems to have several answers to your exact question

https://www.ukworkshop.co.uk/forums/two-questions-drilling-hss-lathe-lubrication-t62152.html

 

[duncanh]

In the past I've successfully used carbide bits intended to drilling ceramic tiles.
Our club's engineer also drilled some for my using a solid carbide drill bit, although I managed to find some incredibly hard HSS planar blades which dulled them. In the end I had most success using an extra thin grinding disk in my angle grinder to cut slots. This was for custom scraper shapes and tips for hollowing but you could do something similar for a parting tool.

 

[Inspector]

Why do you need to drill holes in the saw blade to make a parting tool? If it is to put rivets in for a handle, like knife scales, they can be left out if you use a good epoxy to bond the handles to the metal. Or have I missed something?

Pete

 

[bassethound]

Why do you need to drill holes in the saw blade to make a parting tool? If it is to put rivets in for a handle, like knife scales, they can be left out if you use a good epoxy to bond the handles to the metal. Or have I missed something?

Pete

That's what i would do as well!

 

[Spindle]

Why do you need to drill holes in the saw blade to make a parting tool? If it is to put rivets in for a handle, like knife scales, they can be left out if you use a good epoxy to bond the handles to the metal. Or have I missed something?

Hi

I would advise on always fitting rivets or some similar mechanical locking system. Just using adhesive risks the epoxy bond failing if the tool should catch and the sharp edges causing injury.

For the sake of a few rivets I know which method I prefer.

Regards Mick

 

[paul-c]

Thanks Paul I gave it a try after my tea and it worked a treat, not very accurate but that could be my ham fists It did the job though so now I have a tidy home made parting tool nice and cheap, thanks

your welcome ianedge ( Ian i assume )
glad to see it worked for you , as i said its the only parting tool i turn to - despite owning a few.
i think its the fact its homemade as well as so good at what it does.
there is something very satisfying about doing a job using a tool you made yourself .
all the best
paul-c