drilling hardened steel

[Brad93]

I was given a few 1/4" carbide bits and for giggles i decided to see what they would drill. Pretty much everything is the answer. Heated a piece of ground flat stock to red and quenched it, the carbide bit went through it like it was chocolate. Drilled holes in other drill bits etc.

I’ve found things they won’t drill. They tend to chip.

 

[skotl]

No guarantees and 'customers items worked on at their own risk', but post it to me and I'll pop a hole in it with my spark eroder / edm with the nearest copper tube that I have to 1.6 mm (will be close).

View attachment 260696

Damn. There's a machine that I didn't even know existed, and now I clearly need to get one!

 

[earthman]

I’ve found things they won’t drill. They tend to chip.

Like what may I ask? Do you know the rockwell hardness of these things too?

I have found that they drill through hardened blades with no problems at all, I have experienced one chip out on me after X amount of use though, not sure if that were just down to wear, a fault etc but overall I'd say that my findings of using carbide bits on hardened material is great.

 

[Brad93]

Like what may I ask? Do you know the rockwell hardness of these things too?

I have found that they drill through hardened blades with no problems at all, I have experienced one chip out on me after X amount of use though, not sure if that were just down to wear, a fault etc but overall I'd say that my findings of using carbide bits on hardened material is great.

A bolt that was mega stuck. To be fair I had tried heating it to remove it. God knows how hard it was but it killed a Guhring 10mm TiAlN Coated Carbide Drill. Probably £30-£40 worth of drill.

 

[ronan]

Damn. There's a machine that I didn't even know existed, and now I clearly need to get one!

Get Yer soldering iron out. Lots of people making them diy. I'd love a wire edm, but no more room at the inn....er shed.

http://www.homebuiltedmmachines.com

 

[Kram]

Decent cobalt drill should go through it. Id probably use a carbide burr to get started if its on the OD, and die grinder for the drill too.

www.ebay.co.uk/itm/5-x-1-6mm-COBALT-STUB-DRILL-HEAVY-DUTY-HSSCo8-EUROPA-TOOL-OSBORN-8205020160-P8/272331427597

 

[Munkul]

I've never, ever had any luck with cobalt drills. Even Presto ones. They just chip.

I've had better luck with Dormer TiN coated ones... drilling through a hardened sprocket once with a 5mm, the entire drill length was glowing red and somehow drilled through... it snapped shortly after that!

Carbide sounds like the answer, to me. Or EDM.

 

[ronan]

If you buy a carbide drill, don't buy just one, as sods law will make sure it will break. I bought a few cheap ones off ebay and they were ok.


Fiver each

https://www.ebay.co.uk/itm/Solid-Ca...4c0dbd44d853cd2191c6|ampid:PL_CLK|clp:2334524

 

[Brad93]

I've never, ever had any luck with cobalt drills. Even Presto ones. They just chip.

I've had better luck with Dormer TiN coated ones... drilling through a hardened sprocket once with a 5mm, the entire drill length was glowing red and somehow drilled through... it snapped shortly after that!

Carbide sounds like the answer, to me. Or EDM.

Cobalt does chip I find. I’ve very few cobalt drills. HSS is cheaper, and very tough.

 

[earthman]

If you buy a carbide drill, don't buy just one, as sods law will make sure it will break. I bought a few cheap ones off ebay and they were ok.


Fiver each

https://www.ebay.co.uk/itm/Solid-Carbide-Jobber-Drills-Europa-Tool-1mm-13mm-801303-HSS-COBALT-DRILL/132762021741?_trkparms=ispr=1&hash=item1ee93baf6d:g:nAgAAOSwxzheorGz&amdata=enc:AQAFAAACcBaobrjLl8XobRIiIML1V4Imu%2Fn%2BzU5L90Z278x5ickkBUIiHwYv5YgVss0WaiENzz7REanQdsV62xAzAiR7QrkFh2kI2vH8hyN9PJ%2F5bDph42p0vk3PRuVi7vFmMlQySGGmmpRz71%2BkUPUtYRRrAXmgDXMTjfplP1MftK7yacKW5SRUELsPebDdt5WSogR2a8c8PNz7k7XQECXKu6gZR69O80ZT40Q10%2BG%2FD6V%2Fhr1h8qzILWLNvf2GzxYHwcVluSNaUqejd28TRPd7W8XkV91m%2FRMxsinwPknYK5Rmi%2BibXUcAUQEdPQVyvJ7cjNW5YxGAP63blne58hqaLv%2FyKLXpIX21RmwdOsTiIdxShjUtFd3XHTAIGgodmZBee7ZtCNvloIom%2BnBupV03RHfIuBwdIo9ocD%2F%2FqMvdcsabNmKLqhgvoG9iLylSXFZb5SBY2ghGrQv4SEQttFggHiaPI%2BuVn%2F6FpcqzErE3iqpqATw58qRRQxmdkjQXFqMdmnbzrHvxt3nsIA9TRdBe%2B3kGWHaGzTn2ceZcNYGpRJfiyYfDpla4KKSMUlG1EgjnRn1q4BmYPYh4YEKd0QryA%2BG80BV8Y%2Bi51hYuKHvpewC8CI3LFSUxuRdjWCdaOjms5nruwyfTSgyXScBVZmtiWFhECAOpk3D12ssnzQTaK38rc4QHE%2FKNV9Xb4Xp%2B2Z3VaXbb%2FlKQekCE%2F4ZtStkavo2oOpRrdUqvEvZ1pS0hWa3NXLeN4Qh9yLCrcFj%2Fu1PUNUQFMNc3VPWlBjlF0f2Dm3ZeOFlLL8ryGwP1%2FbuFx0%2BZjvnrDKGjP92u3p0%2Fjgpq6%2BFaRw%3D%3D|cksum:13276202174158ae18f6c35d4c0dbd44d853cd2191c6|ampid:PL_CLK|clp:2334524

Thanks for the link,...near fainted after looking at the price of a 13mm one though. Lol

 

[lotus 30]

Well i tried it on an old shaft and got a set of drills off a mate did not scratch going to go with @awemawson and spark erode it safest option for me.
Brilliant response i thank you all very much.
Andy

 

[Morrisman]

I was given a few 1/4" carbide bits and for giggles i decided to see what they would drill. Pretty much everything is the answer. Heated a piece of ground flat stock to red and quenched it, the carbide bit went through it like it was chocolate. Drilled holes in other drill bits etc.

I’ve seen such carbide drill bits displayed at car and bike shows, generating holes in files, other drill bits, stainless disc brakes etc.

I always thought they were just a scam......

 

[tom2207]

Do you have any 1.6mm masonry bits, Tom?

3mm and a flap disc , I certainly wouldnt be stuck for one if i needed one .
Just checked ,, my 3mm bit is missing ,, Id have to use my 2mm and buff a lot less off it.

id drill through thee case hardening with the 3mm then use what ever took my fancy its an oil way so it really wont matter what size the majority of the hole is , as long as part of it is 1.6mm .

Then again , Im not very often stuck for anything .

 

[ronan]

I’ve seen such carbide drill bits displayed at car and bike shows, generating holes in files, other drill bits, stainless disc brakes etc.

I always thought they were just a scam......

Nope, i've drilled out broken HSS taps successfully with carbide. Worth their weight in gold at times.

 

[Kram]

Another option is drill an easier size, say 4mm, ream, then fit a 1.6mm drilld plug of something softer.

I have ordered these.
www.ebay.co.uk/itm/x5-off-2-1mm-diameter-carbide-jobber-drills-engineers-quality-drills-light-use/254232281622

 

[awemawson]

Andy's MGA gear shaft arrived and I duly popped a 2mm hole radially to give an oil feed to his wider bearing. Only problem was that the axial hole didn't extend as far down the shaft as he wanted the new hole.

I stood the shaft upright and popped a 3 mm hole down it's axis deep enough for the new hole. Only problem was that I'd popped the radial hole just deep enough to meet the none existent (at that point) 4.7 mm original bore.

So I had to set it back up horizontal to deepen the 2 mm hole to join up - so we got there in the end !

 

[lotus 30]

Andy's MGA gear shaft arrived and I duly popped a 2mm hole radially to give an oil feed to his wider bearing. Only problem was that the axial hole didn't extend as far down the shaft as he wanted the new hole.

I stood the shaft upright and popped a 3 mm hole down it's axis deep enough for the new hole. Only problem was that I'd popped the radial hole just deep enough to meet the none existent (at that point) 4.7 mm original bore.

So I had to set it back up horizontal to deepen the 2 mm hole to join up - so we got there in the end !


View attachment 261301
View attachment 261302
View attachment 261303

I don't quite no the words i am very grateful to you for doing it for me and great to see the machine in action never seen one before. Although as a apprentice electrician i did see the power of sparks blew up a few screwdrivers all part of learning then i suppose. Many thanks Andrew for going to all that trouble. I am 18 months into this rebuild of a 1956 lotus eleven got a headache today doing the wiring it does take a bit of getting back into.

 

[tom2207]

well done ,, even I couldnt have done that with a masonry bit.

 

[My Old Landy]

The power of this forum is fantastic!

 

[lotus 30]

The power of this forum is fantastic!

You are not kidding got to be the best one on the web andy