Previous in Forum: Thick Thin Nut   Next in Forum: What is This Plumbing Item?
Close
Close
Close
16 comments
Participant

Join Date: Feb 2011
Posts: 4

2mm Drill Bit Broke in 20dia SS Rod

06/25/2011 2:57 AM

Hello Every1,

If we remove O from hello it will be hell. thats what i feel now.

while making 2 M.M. Drill hole in S.S. 304 Rod. Drill bit broke in 2 parts. i removed job from lath chuck & knock on wood. 1part came out other got stuck inside 15mm deep its not moving out. my friends if you have any advice for me to remove drill bit broken part please let me know.

God love you all.

Thanks

Sujit

Register to Reply
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".
Guru
Technical Fields - Technical Writing - New Member Engineering Fields - Piping Design Engineering - New Member

Join Date: May 2009
Location: Richland, WA, USA
Posts: 21024
Good Answers: 791
#1

Re: 2mm drill bit broke in 20dia ss rod

06/25/2011 3:24 AM

If you use too slow of a feed rate, the SS can work harden and become very difficult to drill/mill/cut. I have had best success with fairly high drill pressure and feed rate, with kerosene as a coolant/lubricant. If the curl or chips are binding, back the drill out a few times to get another fresh cut.

__________________
In vino veritas; in cervisia carmen; in aqua E. coli.
Register to Reply
Participant

Join Date: Feb 2011
Posts: 4
#3
In reply to #1

Re: 2mm drill bit broke in 20dia ss rod

06/25/2011 6:02 AM

I am using plain oil & cutting oil. 1st time when i use High feed rate centre drill broke when it touched object.

Slow feed rate & oil worked but for this time thing went wrong.

Bye

Register to Reply
Commentator

Join Date: Dec 2009
Posts: 87
Good Answers: 5
#14
In reply to #3

Re: 2mm drill bit broke in 20dia ss rod

06/26/2011 3:31 PM

Hello when the drill bit disintegrates when it touched the object then I would suspect that the drill bit did not ht the center of the rotating object or the drill was asymetrical sharpened. With small drill bits this is fatal.

So when I was tought the trade we always had at first use a short & stuby machinists drill to really establish the center of rotation. under these circumstances smaller drill bits start better. I also was tought that the correct rpms for the drill size can be obtained from a list in any machinists handbook. Getting the piece out is hell - I think the best is redo the job.

Register to Reply
2
Guru
United Kingdom - Member - New Member Hobbies - Musician - New Member Engineering Fields - Mechanical Engineering - New Member Hobbies - Target Shooting - New Member Engineering Fields - Power Engineering - New Member Hobbies - Fishing - New Member

Join Date: Mar 2007
Location: South-east corner of Spain 50 48 49.24N 2 28 27.70W
Posts: 1508
Good Answers: 31
#2

Re: 2mm drill bit broke in 20dia ss rod

06/25/2011 4:02 AM

You need a friend with an EDM (Electrical Discharge Machine) to spark that little piece of hell out for you otherwise I see a very hot future for you my friend

__________________
“It's kind of fun to do the impossible.” Walt Disney
Register to Reply Good Answer (Score 2)
Participant

Join Date: Feb 2011
Posts: 4
#4
In reply to #2

Re: 2mm drill bit broke in 20dia ss rod

06/25/2011 6:04 AM

Dont think so i will get EDM.

Thanks

Register to Reply
Associate

Join Date: Jun 2011
Posts: 37
Good Answers: 1
#5
In reply to #4

Re: 2mm drill bit broke in 20dia ss rod

06/25/2011 8:14 AM

A crazy idea but that I have used with some success.

Line the inside of the hole with insulation. Then lower the weld wire from a mig torch to just touch. Switch on in bursts . You may burn the bit of drill out. also if it heats the bit to red heat, another HSS drill will cut it, but carefully.

Register to Reply
Guru

Join Date: May 2006
Location: Placerville, CA (38° 45N, 120° 47'W)
Posts: 6137
Good Answers: 246
#9
In reply to #2

Re: 2mm drill bit broke in 20dia ss rod

06/26/2011 12:50 AM

As Truman indicated, a plunge EDM can do it rather easily, although not very rapidly. Including setup, it would take me most of an hour to do it, depending on how long the broken piece is. I have removed several broken taps and small drills that way.

When looking for someone to do it, make sure you specify plunge EDM. In my limited experience, wire EDMs are more common, but they won't do this job.

You don't say where you are located, but I suspect it is not in the USA...

__________________
Teaching is a great experience, but there is no better teacher than experience.
Register to Reply
Guru
India - Member - New Member Engineering Fields - Electromechanical Engineering - New Member

Join Date: Oct 2006
Location: India, 200 Km. North of Delhi.
Posts: 1391
Good Answers: 53
#6

Re: 2mm Drill Bit Broke in 20dia SS Rod

06/25/2011 11:32 AM

You can think of leaving it in an acid bath that have very low reactivity with SS 304 but can etch HSS (DRILL) quickly.

__________________
Jesus gave me message, Gandhi gave me method, M.L.K
Register to Reply
Guru
Panama - Member - New Member Hobbies - CNC - New Member Engineering Fields - Marine Engineering - New Member Engineering Fields - Retired Engineers / Mentors - New Member

Join Date: Dec 2006
Location: Panama
Posts: 4273
Good Answers: 213
#7

Re: 2mm Drill Bit Broke in 20dia SS Rod

06/25/2011 11:55 PM

You might want to try heating the rod- but that depends on what the rod is going to be used for- getting it hot enough to turn loose of the drill bit will likely change the crystal structure.

Can you drill from the other end?

Register to Reply
Participant

Join Date: Jun 2011
Posts: 2
#8

Re: 2mm Drill Bit Broke in 20dia SS Rod

06/26/2011 12:46 AM

Try A real quick fix, use a strong Magnet and hold under the hole and bump the rod on a solid surface.

Register to Reply
Guru

Join Date: Apr 2006
Location: Cincinnati, Ohio, USA
Posts: 662
Good Answers: 48
#10

Re: 2mm Drill Bit Broke in 20dia SS Rod

06/26/2011 12:54 AM

This is a two-step process.

First, build a simple electromagnet using a large washer- maybe 6-8 mm larger than the rod's diameter and wrap it with a single loop of AWG 12 insulated wire. Set up a switch connected to a 12 VDC battery and each end of the wire coil.

Place the rod inside that magnet assembly with the drill hole on the bottom and the magnet about 15 mm above the likely location of the drill end.

Connect the leads of a welding unit to each end of the rod and hold the rod with a vise grip using about 2 mm of fiberglass insulation between the jaws of the vise grip and the rod- clamp tight but not enough to damage the rods finish.

Power up the welder slowly to begin heating the rod due to resistance. When the rod is too hot to touch, stop increasing the power of the welder but keep it running.

Energize the electromagnet and slowly (1 mm per second) begin to lift the rod through the magnet ring.

When the the welding lead at the lower end of the rod gets within 10 mm of the magnet, turn off the welder and disconnect the lower lead connection. Continue to extract the rod through the magnet.

When it passes through the magnet, the dirll bit should be extracted and caught by the magnet. Turn off the magnet and the drill will fall to the floor.

Then- use adequate lube oil to continue drilling the COOLED rod.

By the way- IF the drill is not extracted the first time, REPEAT the process but heat the rod another few amps hotter the second time.

__________________
NO MATTER HOW WELL YOU HAVE DONE SO FAR, ALWAYS TRY TO BE BETTER TOMORROW.
Register to Reply
Guru
Popular Science - Weaponology - New Member Safety - ESD - New Member Hobbies - Fishing - New Member

Join Date: Sep 2006
Location: Near Frankfurt am Main, Germany. 50.390866N, 8.884827E
Posts: 17996
Good Answers: 201
#11

Re: 2mm Drill Bit Broke in 20dia SS Rod

06/26/2011 6:51 AM

You usually weld using the same metal, so if a slightly smaller HSS drill was wrapped in insulating/Teflon tape (to stop it contacting the sides of the hole), connected to a switched on stick welder, then pushed down the hole till it contacts the broken bit, maybe it would weld itself to the other part......at least it stands a chance!

Once connected/welded, turn the new HSS drill a little anticlockwise first as the original drill bit end is probably slightly "buried" on a cut in the SS rod (nobody else mentioned that!), which is probably why it won't drop out!

By the way, I have never done this myself, but I had an acquaintance that according to him did it fairly regularly on expensive castings, but don't ask me what metal!, with good results - he said!

It stands a chance I feel......

Best of luck.

__________________
"What others say about you reveals more about them, than it does you." Anon.
Register to Reply
Guru

Join Date: Oct 2009
Location: sometimes Wales,UK.. was Libya, now Oman!
Posts: 1715
Good Answers: 116
#12

Re: 2mm Drill Bit Broke in 20dia SS Rod

06/26/2011 7:35 AM

if all else fails.. throw it away and start again.. this time.. take your time and lubricate correctly and drill at a suitable speed.. but i think you know the last part already!!

__________________
The square root of nothing is what you make it!
Register to Reply
Active Contributor

Join Date: Nov 2009
Location: Houston, Texas,USA & Bonacca, Bay Islands, Rep. Honduras.
Posts: 21
Good Answers: 2
#13

Re: 2mm Drill Bit Broke in 20dia SS Rod

06/26/2011 11:41 AM

Put it in a vise and get a small sharp cold chisel and give it a wack. Need a point or small chiesel, If you grind one down to a small size do not heat it up. Sharpen it manual on a sharpening stone or keep it cool best you can. I am not sure how far down in the hole your piece of bit is. Hopefully you can get a chiesel point down in there and find an edge to bang (pry force) A small screw driver may work for you but use caution bang little easy.You have a two hard brittle materials striking each other-easy to crack one. After one wack manally pry at it. Do not bang so hard you bend up your rod. Perhaps you can grab at it with a diagonal cutter (wire cutter plyers). Some of them are tiny and perhaps can get a bite on your piece of bit.

If your bit was starting to break through the other side when itr broke, bank on that side with a Tiny punch (round flat end, no point). Keep at it you can get it out. Just do not use so much force that you wreak your piece. That piece of drill bit is jambed in but it is a tapper so once it is jared it can come loose.

Register to Reply
Associate
Hobbies - Target Shooting - New Member Hobbies - Automotive Performance - New Member

Join Date: Mar 2007
Posts: 31
#15

Re: 2mm Drill Bit Broke in 20dia SS Rod

06/26/2011 11:06 PM

I would think something like H2SO4 would get rid of a lot of the drill before it ate much 304. Would pay to check with a chemist. If not that, there will be something else to do it. Rex Devantier.

Register to Reply
Member

Join Date: Aug 2010
Posts: 5
#16

Re: 2mm Drill Bit Broke in 20dia SS Rod

06/27/2011 6:57 AM

Please do hammring at opposite side of drill hole to remove breaked drill bit 2nd part.

Register to Reply
Register to Reply 16 comments
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".
Copy to Clipboard

Users who posted comments:

Andy Germany (1); brich (1); Captkirkconnell (1); cwarner7_11 (1); dkwarner (1); energygod (1); Mr. Truman Brain (1); oldwidget (1); PrashantVS (1); rakesh_semwal (1); Rex Devantier (1); ssujitp75 (2); Tornado (1); uli_newBuilder (1); ve7reh (1)

Previous in Forum: Thick Thin Nut   Next in Forum: What is This Plumbing Item?
You might be interested in: Guide Bushings and Drill Bushings, Drill Bits, Drills

Advertisement