Help / Advice on drilling

[Hunter_zero]

Hi all,

Can anyone please give me some help/advice on the best sure fire way to drill a hacksaw blade.
All the HSS drills I have here don't make a mark on the blade. I don't want heat the blade, just drill a couple of holes. (any bit's I can get from B&Q?)

Any help would be VERY appreciated.

John

 

[billycan]

Hi Hz
Some of the cobalt steel drills are hard enough to drill hardened steel, although might be a little bit expensive just to drill a couple of holes?

 

[Dave Budd]

Try annealing the area you want to drill. Either use a torch to heat it to red and let it cool (wrap the bit that you want to stay hard with a wet rag) or use the blunt back end of a drill bit (slightly larger diameter than the hole) and 'drill' onto the area to be softened. if you try the latter you will needa firm backing under the blade, use high speed and lots of pressure, this will very locally heat the area to be annealed and thus drilled

When annealed centre punch the hole and try drilling. Use a slow speed when drilling steel or you blunt the drillbit quickly! If you still can't get through try drilling a smaller hole and open it with a larger one

If it still ain't working, give up

 

[wingstoo]

I knew a guy who used to put holes in hacksaw blades with an Arc welder! litterally blowing a hole in them.


But as mentioned above, a slow speed and a good drill bit will be best, try to ensure you have a good solid base board underneath and the blade well clamped to it.

LS

 

[jojo]

just found that in a book: "cut the head from a nail and flatten the point. Secure the nail in a drill press, press the flattened nail on the hole mark, run drill at high speed until the heat generated turns the spot blue; do the same for other spots, and the steel is selectively softened, then drill the marks at low speed with a high speed twist drill".

Now, I have not tried it and don't know if it works! Makes somme sense, though. Let us know if you do try.

 

[Hunter_zero]

Thanks everyone for the info!

I'm making a RM style knife out of a hacksaw blade and need to drill the holes for the handle

Shaping the blade was easy (bench grinder). I popped the blade in my log burner (using coal at the mom) and dropped the blade in to an ice bath. Blade was coloured a lovely black, not soot or burn, looked more like paint.

A HSS drill bit, will not even mark the blade, not even scratch it" A centre punch makes no mark either

My plan was to buy a diamond drill bit or carbide drill bit to cut the hole. I like the idea of using a blunt nail but this blade is VERY hard.
Out of interest I did heat the handle to cherry red and put it aside to cool over night, but never the less the HSS drills will not mark it!

Again, thanks for all your help!

John

 

[jojo]

The other trick that may be worth trying is to use a masonery drill bit, they haveTCT tips and I have heard of people using them, they are cheap and easy to get.

 

[retrohiker]

I'm with JoJO's suggestion of trying masonary bits. I tried drilling out a rivet hole for a Green Mountain knife blade and used a titanium coated drill bit. Nothing but smoke!!!!! Tried a masonary bit and it worked like a hot knife through butter. Not expensive either.....

 

[Hunter_zero]

I'm with JoJO's suggestion of trying masonary bits. I tried drilling out a rivet hole for a Green Mountain knife blade and used a titanium coated drill bit. Nothing but smoke!!!!! Tried a masonary bit and it worked like a hot knife through butter. Not expensive either.....

Gave the blade to a chap in an aero-space factory today.

I explained that it was VERY hard steel. He did cut one hole with a masonry bit BUT I begged him to use the spot welder to cut the second (closer to the blade). Okay he said, it'll be done by the time you come back.

To cut a long story short, he found me and admitted he wanted to prove me wrong and used a drill for the second hole and shattered the blade in to two

Never mind I told him, just three days work gone.

What annoyed me was the fact the he wanted to "prove me wrong", instead of using the spot welder which we both knew would do the job.

Never mind. I'll make another one day.

John

 

[chrisanson]

Hello,
I have used masonary bits to drill out broken taps so they should be up to drilling hacksaw blades. But you must re-sharpen the the masonry drill the same as an ordinary HSS drill( preferably on a green wheel). If it is not re-sharpened it will not cut even mild steel.
Hope this helps .
Chris

 

[chrisanson]

Ho ya and use plenty of cutting oil or past (even washing up liquid will do a pinch)
Chris

 

[C_Claycomb]

Man, that is gutting

I really feel for you. I have had a blade destroyed by someone who should have known better and in their case they weren't even apologetic. It can be pretty agravating.

I do hope that you kept the pieces though! Those can be your trial samples to test methods of drilling. Better to know your chosen method works than to try it on another blade.

Now, by the sound of it you are using one of the really big industrial reciprocating hacksaw blades, about 24"x2"x3/32, solid M2 HSS. Those things are HARD. They are also red hard, so trying to anneal them is all but a non-starter. They are incredibly abrasion resistant with high levels of tungsten. I had a go at making a blade from one recently and couldn't get a solid 1/8" carbide drill to make more than a little dent. That same drill has cut hardened and tempered O-1 without a problem. That is not to say that solid carbide is not the way to go, just that my drill was not set up with the correct angles for this kind of work.

Have a look at the Cromwell catalog, they sell a good range of carbide drills if you want to try that.

It was suggested that I try a Stellite drill, but that would be expensive to try, and you need a lot more power than my drill press can muster.

The last option is not to drill at all, but to make a pinned mortise handle. Form the tang narrow enough to fit well within the handle shape, cut several U shaped notches in the tang with a cut off wheel, lay it on the wood to be mortised and drill through the wood where the tang isn't. When you glue everything up, the pins will interlock with the notches in the tang and prevent the blade from moving.

Whatever you do, best of luck, and be sure to show us a photo!

 

[Hunter_zero]

Man, that is gutting


The last option is not to drill at all, but to make a pinned mortise handle. Form the tang narrow enough to fit well within the handle shape, cut several U shaped notches in the tang with a cut off wheel, lay it on the wood to be mortised and drill through the wood where the tang isn't. When you glue everything up, the pins will interlock with the notches in the tang and prevent the blade from moving.

Whatever you do, best of luck, and be sure to show us a photo!

I have to admit to being ever so slightly GUTTED! The blade profile was exactly the same as the RM bush craft knife, very nice and totally finished, polished and all. This explains my feelings :sulkoff:

Okay, the bright side is that I just reshaped the blade, now it's a lot smaller and looks like a Buck 110 with the exact same set-up as you described (narrow tang).

All I have to do, is file or grind the blade profile (when I have a little more light) and start polishing again.

I guess I'll make a small sheath type knife, sort of a mini bowie of sorts, good for rabbits I guess. Anyway, it's a brighter side than sulking around the house like a wet dog tonight (really was proud of the blade).

Yes, I'm using big industrial hacksaw blades, very finest quality money can buy. I'm lucky in that I carry out pest control visits on some major factories and often get the chance to pick up damaged blades. This particular blade was ordered specially to try and cut titanium sheet and was very expensive. It lasted ten minuets and snapped.

The bench grinder has trouble shaping it, but it will do it.

John

 

[garbo]

Sorry your blade shattered but it was the best thing that could happen
(a) it didnt shatter while you worked on it or were working with it
(b) it shattered before you invested any more time and effort in it
(c) hacksaw blades are always too fragile or brittle for good knife blades (but some do take a great edge) they stand virtualy no side loading at all.
(d) I seriously doubt that you can re harden a hacksaw blade should you manage to aneal one in the first place, I suspect they are made of air hardening steel like files these days, many have a flame hardened cutting edge
a much better choice of steel would be a spade blade or old car leaf spring that will aneal and re temper IMHO restated IMHO
I have tried to make knives from those big power hacksaw blades and leaf springs the spring was much better, but the spade blade knife I saw was the best of the lot
all the best with your next attempt

Garry

 

[Hunter_zero]

Well after all the hassle and trouble with making a knife this is what was born from the wreckage of the RM knife type blade.

It was never meant to be pretty, just a functional knife with a sharp edge.
Not sure what I will do with the knife, most likely use it in work for this and that, may even use it for gutting rabbits.