# I need some help drilling into a metal bolt



## Eds_tls

Theres a wide range of bolt hardness. Everythng from unhardened mild steel that is super soft up to a high strength alloy steel hardened socket head cap screws...and everything in between.

We use carbide drill bits sometimes, but theyre expensive and break easily if youre not careful. Or you could take it to a machine shop and they can EDM a hole in it for you. But that will cost some $$$


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## ddawg16

Is it a grade 5 or grade 8 bolt? If you have 5 lines on the head....that is a grade 8....if only 3....grade 5. A grade 8 is going to be hard to drill into.

I guess most of us would use a drill press. Slap that bolt into a drill press vice and start drilling.....


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## jbfan

What kind of bolt?

Some bolts are hard to drill into.


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## md2lgyk

Drilling into metal works better if you don't turn the bit too fast.


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## user1007

Speed does make a difference but unfortunately you do not have speed control on your drill. Most drill presses do. Generally, the bit should be stronger than the material you are trying to drill so you might try a carbide bit but heed the warning in the post about them being brittle. 

What are you trying to accomplish? If the bolt head is broken you might try using an extractor. You will still have to drill a hole for it but you won't, if it works, have to drill out the whole bolt.


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## toolaholic

Get blu moil or dewalt cobalt drill bits. Cobalt is very hard and doesn't dull easily.


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## wkearney99

A drill press is among the best tools to have. Even a bench-mounted one would be better for the purpose than a handheld, let alone cordless, drill. With a drill press you get control over speed and pressure, while keeping things straight. Pickup one secondhand, you'll be staggered that you didn't buy one a long time ago.


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## amodoko

Thanks for the replies and suggestions everyone, I appreciate it. To answer some of the above questions above I am attaching some pictures to this post of what I have done so far. I'm not sure what type of bolt it is since I have already drilled a bit into the head and can't see the 3/5 line markings. Also, the reason I am drilling into this bolt was so I could drill out the bolt completely to access the rubber washer in a frost proof faucet so I could replace it (the faucet was leaky). The bolt is over 30 years old and it had rusted so bad that it was stuck. I had tried penetrating oils, tapping it with a hammer, using screwdrivers and socket wrenches and it wouldn't budge. I can't use a drill press in this case since the bolt is attached to an immovable object, thus the job is out in "the field" as some pros would say. It is broken off, but just impossible to pull off without damaging the faucet itself. It's one of those situations where you need all the force you can get to get it off, but if you use too much force it will break the inner workings of the faucet I believe (and that is even when I stabilize the copper piping). 

At this point, I am actually just going to replace the faucet completely and solder a new one in, so drilling into the bolt is no longer necessary. But I am going to continue to drill into the bolt anyways because I really want to learn how to do this so if I run into this issue some day down the line (and I'm sure I will), I will know exactly what to do. 

Even though HSS drill bits should be sufficient, I think I am going to buy myself some cobalt bits too. If I understand correctly, cobalt can be used for the hardest of drilling jobs, and the bits are cobalt through and through vs the other harder bits which are just coated, correct? If you think I should get another type of bit let me know, I'm open to suggestions.

With the attached pictures, you can see my attempt at trying to drill through the bolt. The little work shown there literally took me about 15 to 20 minutes, and it barely did anything to that bolt. 

I really do want to learn how to do this properly now, so when this happens again in the future I'll know exactly what to do.


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## toolaholic

Where you going to drill it out completely or use a screw/ bolt extractor? Looks like maybe after some more drilling you could try a extractor. Cobalt bits rule when it comes to hard steel/ stainless steel/ cast iron etc.


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## ddawg16

Looks like your using too big of a bit....

Start small.....say like a #25 or even smaller...then work your way up.....

BTW.....just how old is that faucet?


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## amodoko

I was planning on drilling it out completely, I didn't really want to do the screw extractor method on this one... but I'll probably try that the next time I need to remove a bolt for fun At this point I want to find a method that works well enough for drilling out a bolt completely though.

I was thinking about starting smaller as well with the bits. I will try that too, to see if that helps much. The faucet itself is roughly 30 years old.


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## DangerMouse

Why can't you use a pipe wrench and pull the entire faucet off? Then just put on a new one.

DM


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## amodoko

Hey DM Yep, I'm replacing the faucet completely, but I made this thread mostly to learn how to drill through a hard bolt. So yes, I'm replacing the faucet, but I still want to learn how to drill through a bolt so when i have to do it again one day it won't be such a hassle.

But you did mention something that got me thinking, I thought you couldn't remove these faucets with a pipe wrench since that would cause the copper piping to twist inside the house causing a possible break/leak in a soldered joint. I thought these had to be cut out with a pipe cutter since they are soldered in, right?


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## DangerMouse

That would depend of course if it's screwed on or soldered, yes.
Mine is a screw on type, easy to pop off and replace if it ever fails. 

DM


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## wkearney99

Had you mentioned it was on a spigot I'm guessing most folks would've said to just replace it. I certainly wouldn't have brought up the drill press notion as it would quite clearly not work for that particular task.

Have dealt with outside spigots on old houses I can tell you it's usually best to always plan to replace it. If you get any resistance, quit while you're ahead. Because once you get it loose you often discover there are no standard parts for spigots. About the only thing you can do is replace a washer (with one that'll crap out MUCH faster) or try to repack the stem (which usually leads to the packing nut breaking).

But to the job at hand, you used too large a bit. Best to use a small one and then use an extractor bit to try and work the old fastener out. An extractor usually looks like a small drill bit but with backwards threads. The idea is as you turn it counter-clockwise it digs itself in tighter, further increase the surface area on which it pushes the old fastener. 

Many spigots are connected by threads. This is often by using a short segment of threaded pipe back to a tee inside the house. You have to hold the tee on the inside and then turn the spigot outside. This makes it a two man job. If you can't get to the inside, well, you're going to have to get to the inside. Drywall and plaster are not that hard to repair. And botching a plumbing job that eventually damages inside walls will teach you this, but you can learn from everyone else's mistakes instead!


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## wkearney99

DangerMouse said:


> Mine is a screw on type, easy to pop off and replace if it ever fails.


Heh, which are supposed to be easy to pop off if they're installed properly in the first place. I've rarely had that luck.


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## DangerMouse

wkearney99 said:


> Heh, which are supposed to be easy to pop off if they're installed properly in the first place. I've rarely had that luck.


Yes, but it was *ME* that installed it!  Good for *50 years* and more!

DM


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## Daniel Holzman

The key to drilling any metal is to use a bit that is very sharp, and is harder than the metal you are drilling into. Strength of the bit is almost completely irrelevant, unless you are unable to drill straight, in which case a bit that is hard but brittle can snap on you.

When a bit is referred to as a cobalt bit, that usually means the steel is coated with cobalt oxide or cobalt nitride, not that the drill is solid cobalt. Similarly, a bit that is referred to as a titanium bit is almost certainly coated with titanium nitride or a similar ceramic material, a solid titanium bit would be very expensive and would not offer any performance advantage over a coated bit. I have titanium nitride bits at home, they work well in metal, but like most bits require oil or water to keep them cool while drilling. Even titanium nitride bits, which are much harder than most steels, will dull quickly if overheated. If they are even slightly dull they don't drill worth a damn, and they are not worth sharpening, so you buy a new set of bits.


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## md2lgyk

That bolt probably only holds on the faucet handle.


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## jschaben

I put a union on mine. Do all the soldering on the bench now
To drill that I would agree with a smaller bit. I'm also not as convinced as you are that your bits are sharp. Cobalt will work well but be aware that they are very hard and also very brittle. You haven't lived till you try to get one of those out after it broke off. DAMHIKT.:yes:


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## s10sleeper

I have found titanium bits work well, but tend to flex alot when they are smaller. I also like cobalt bits as they have been the only thing I have been able to use to drill spring steel. My trick has always been to us a small punch to set a pilot, and while drilling, an excellent lube is transmission fluid or PB blaster works too, it helps to pull the metal away so the bit doesn't build it up on it plus prevents overheating. By the time you invest in decent cobalt bits, it would be cheaper to just replace the spigot. Easiest way is to shut off the water main, remove it from inside the house where it joins and take it to a hardware store to compare it.

There is no point in buying low name cobalt bits as they are still pricey, as I found that one cobalt bit can be as expensive as a set of titanium, but even titanium bits should drill through a screw.

Another big help is reverse thread drill bits, I use them with my screw extractors all the time.


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## Rochsolid

You need a new drill it sounds like


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## notmrjohn

amodoko, good thing you explained you really did want to learn about drilling into a bolt. This looked like a time when the question asked wasn't the question that should have been asked. Sure helps to explain *why* one wants to do something. I was in a thread the other day where OP wanted to remove lower spray arm in dishwasher. I had experience in doing that with similar model. Not difficult, but some easily breakable moderately expensive parts involved that are kinda difficult to describe without diagrams and/or a lot of verbage.My one finger typed response was more verbose than normal. Did I say easily breakable? Especially if one does not know exactly what one is doing (ahem) and did I say I had experience in removing the arm?Turned out what she really wanted to know was how to clean her dishwasher of _possible _mineral build up and _possible_ glogging of spray holes. Broken $60 part vs $1 worth of vinegar and some tooth picks.


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## Rikbarry

I have a very similar challenge. I have rigged up something in my car intended to hold my phone. I have a mount for the phone that I want to attach to this thing I've rigged up. 

There is a female thread inside a small nut. The phone mount has a male bolt that matches this thread, and needs to screw into it. 

However,there is another bolt threaded into the back side of the nut, and I allowed it to come too far forward into the nut so it doesn't leave enough room to thread for the front bolt to grab. That rear bolt is mounted to a space on the dashboard with strong epoxy putty, so trying to avoid messing with it.

Instead, I'm trying to drill onto the rear bold from the front in order to shorten it enough for the front bolt to catch. 

I tried a cobalt 1-8" bit, but it's hardly made a dent. I haven't yet tried to drill at half speed as someone suggested here. Any other suggestions would be appreciated. Some folks have mentioned carbide bits. Is this worth trying? Thanks!


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## wkearney99

Why not just get a longer threaded standoff or spacer instead of that bolt? One with either threads all the way through. This being one such example: http://www.grainger.com/Grainger/Hex-Standoff-6RB72?Pid=search

If they don't sell one short enough then just cut it to the desired length.

That or get a solid chunk of aluminum and cut whatever threads you need into it. A tap and die set isn't very expensive. Just remember to use cutting oil (a small bottle is likely a lifetime supply for most DIY folks). One tip, use a left-over medicine bottle that has an eyedropper as a means to apply the oil, much neater than just about any other way to apply it.

Or did you glue the nut onto the bolt? Epoxy isn't the best adhesive for this sort of thing, which is likely a good thing.


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## Rikbarry

The nut is sitting in a recessed inset that holds in place and keeps it from turning. It part a manufactured mechanism (ProClip) that a manufactured phone holder seat (ProClip) bolts into.

I haven't tried using cutting oil, so that's next.


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## wkearney99

Unless you remove it from the car it would be unwise to use the oil in there. It'll stain. That and it's probably not going to work anyway.

Which mount is this? I've had various Pro-Fit and ProClip mounts over the years. None have required this sort of dance. There's almost always some other combination of mounting clips to avoid hassles like this.

Meanwhile, you didn't answer my question, is the nut in there already glued on? If not, remove it and just use a standoff to get your greater depth.


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## Rico_44

Hi Amodoco, you don't say what type of metal the bolt is made of, where is it installed or is it loose held on a vise.
I really don't like to drill into metal with a battery operated drill motor unless it's a small project, you're putting that unit into a lot of stress. If you have an electric drill motor I think you would have better results. 
a lot of things take place when drilling but none can be met by drilling by hand.
maybe I can help you if you are more specific. if you don't know the type of metal at least where does the bolt go on, how deep you're going. let me know and see if we can figure out something. take care stay safe,and "measure twice and cut once". Rico_44
sorry I hadn't seen the pic.


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## daveskye

*how to drill through screws and bolts*

I had the same problem. I wanted to drill and tap a hole through a 6mm wood screw - made of hardened steel. Putting the screw into a lathe did nothing!
The solution was to take the screw (or bolt) in a pair of pliers and hold it over a gas ring until it is red hot. Keep it there for a short while to ensure it is uniformly heated.
Then slowly raise the held screw away from the heat source - take as long as you can be bothered - so the the temperature slowly falls. Finally leave the screw to cool to room temperature - the time taken will obviously depend on the size of the screw. DO *NOT* COOL THE SCREW IN WATER.
When the screw is back to room temperature it can be drilled.
This process is ANNEALING.

Having drilled and tapped the hole, I wanted to re-harden the screw. 
Once again, heat the screw over the gas ring to red heat and hold it there a while to ensure complete heat uniformity. Then plunge the screw into quenching oil or hot water so that it cools quickly - but not *too* quickly. This will re-harden the steel. Quenching TOO quickly will make the steel brittle.

In my application, I was then able to screw the screw into hard wood, without damaging the screw head and the subsequently use my drilled and tapped hole for its purpose.
Good luck.


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## Thurman

@ Rikbarry: Does the nut in the photo come off? IF so, you could use a "coupling nut" on this. A coupling nut is just a long nut mainly used to connect threaded rod together. These can be found at Lowe's and Home Depot, I've purchased them from these stores, or there may be a different branded home improvement store in your area.


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