How to Drill Out a Broken Bolt?
I over-torqued four bolts in the lower unit of an outboard, and the
heads of three bolts broke off. I managed to remove one of the broken
bolt using a Dremel tool and a diamond grind bit. But I cannot remove
the other two broken bolts using the Dremel tool. Based on the past
posts in this newsgroup, I learn that the best option in this situation
is to drill out the broken bolts. I would like to learn the details of
the way to drill out the broken bolts. My question is:Which size of drill bit do I need? Should it be as large as the hole
where the broken bolt is? Related questions: The bolts are for securing the water pump housing for the
impeller. The hole for the bolt is at the edge of the water pump base |
jaykchan
Oct 25
2006
|
| I wouldn't worry about it. Sounds like the one thing the hardware guy
neglected to mention is that they don't always work. |
Ernest
Oct 28
|
| IOW, corrosion formed around the bolt threads creating something that looks
like a threaded hole. That sounds plausible enough for me. > Do we need to re-apply the heli-coil insert whenever we
> replace the bolt (like when we need to replace the impeller)? The coil will probably stay in there forever. I suppose it's possible for it
to back out when you remove the bolt, but I've never seen it happen. |
Ernest
Oct 28
|
| following well considered thoughts to the readers of rec.boats:
Good point. They tend to be a poor excuse for a reliable tool....
judging (1) from my experience with them (no, I've never broken one)
and (2) the number of them that I have had to drill out that others
have broken off (no fun, but very profitable)....
|
Gene
Oct 28
|
| Jimmy is screwing with his karma again. |
JohnH
Oct 28
|
| === As a point of interest, I'm curious how you do that. |
Wayne.B
Oct 28
|
| Myself and every other person I know takes a hammer and gives it a little
love tap to set the teeth of the Easy Out. But when you break one, you will
not call it an easy out. |
Calif
Oct 28
|
| That's nice, but Jay obviously has no feel for these things, so he's better
off to see if it works first without the hammer. |
JoeSpareBedroom
Oct 28
|
| OK, now I know that I am not supposed to use it like a drill bit, and I
am supposed to use the tap-wrench. In other words, the hardware store
owner gave me the correct instruction. There must be something missing
in the "execution". Jay Chan |
jaykchan
Oct 27
|
| And Jay....if and when you respond to this message, and mine (before
Gene's), please do not mention the motor, or who's fixing it now. That'll
just clutter this branch of the discussion. Let's deal with your approach to
this particular tool. It's important. |
JoeSpareBedroom
Oct 27
|
| I have brought the lower unit to a marine mechanic, and he will use a
coil insert to repair the messed-up-threaded hole. Thanks anyway. Hopefully, someone else has a similar problem will be able to take
advantage of your suggestion. Jay Chan |
jaykchan
Oct 27
|
| These tools come in various sizes. This is why I told you to measure the
size of the hole you drilled into the bolt, write that down, and take the
piece of paper to the store. On the back of the tool's package, there's a
chart which tells you what size tool to use with different hole sizes. With
the correct size, you put the tool in the hole and with no more force than
you can apply with your fingertips, you'll feel it grab tight when you turn
it counterclockwise. That's opposite from the direction traveled by the
hands of a clock. If the tool doesn't grab right away, you can put a little
pressure on it with your hand and turn it again. Then, you grab the square
top with a wrench and turn counterclockwise. |
JoeSpareBedroom
Oct 27
|
| Thanks for your kind words. Jay Chan |
jaykchan
Oct 27
|
| >brought the lower unit to his store. One question that I would like to
>ask you: Do we need to re-apply the heli-coil insert whenever we
>replace the bolt (like when we need to replace the impeller)? Quoting from here: http://www.emhart.com/products/helicoil/standard.asp "Screw-Lock Inserts positively secure threaded members against
loosening caused by vibration and shock. They have a high reusable
factor due to the exclusive HELI-COIL Resilient Screw-Lock which
permits frequent removal and reassembly of bolt without appreciable,
loss of torque." |
Wayne.B
Oct 27
|
| That's just not exceptablized. |
basskisser
Oct 27
|
| I know one that is a friend of mine who certainly would. He's another
black belt! Oh, and he makes a mean grilled tuna, too! |
basskisser
Oct 27
|
| I learned a bunch of useful stuff in home-ec back in Jr. High. One of
which was learning to sew, which has come in handy for automotive and
marine upholstery. I'm a good cook too, though most of that I learned on
my own. Sure I still found shop class and welding to be more interesting, but
both were useful. |
James
Oct 27
|
| I learned to sew, type, cook, wash and iron clothes and a few other things
in Uncle Sam's Canoe Club. Eisboch |
Eisboch
Oct 27
|
| Yes, I used the Dremel tool with a diamond grind bit to form a slot on
top of one of the broken bolt, and I used a screw driver to remove that
bolt -- successfully. But this didn't work for another two bolts that were sunk inside the
holes. The pointy grinding bit simply could not have a good angle of
attack on the bolt surface. What ended up happening was that the two
ends of the slot were slightly lower than the center of the slot and
this weakened the slot. When I used the screw driver to turn the bolt,
I ended up stripping the slot. But this is kind of behind me now. As mentioned in my another reply, I
found an easy way to remove the broken bolts by simply removing the
water pump base, and this allowed the broken bolts to show up in the
open, and I used a channellock piler to remove the broken bolts. Nice to talk with you. Jay Chan |
jaykchan
Oct 26
|
| Look at the bright side. You are going to have a very well stocked tool box
by the time you are finished with this project. :-) Eisboch |
Eisboch
Oct 26
|
| So you figure the women will be the kitchen slave. Not much more pathetic
than a guy who has to go to Burger King because he can not cook anything! |
Calif
Oct 26
|
| Do you mean I am not supposed to use a hammer to work with the screw
extractor? I am under the impression that I am supposed to drill a
hole in the middle of the borken bolt, and hammer the screw extractor
down into the hole, and then use some kind of handle bar to lock on the
screw extractor and turn counter clockwise, and hopefully the screw
will back out. This was exactly what the owner of the hardware store
told me to do. May be we are talking about two different types of screw extractors?
May be you are referring to the type that is like a drill bit, and we
are supposed to use it with a power drill (running in reverse) to dill
and back off the bolt? I could not use that type because the bolt was
sunken inside a small hole that the special drill bit was too large to
fit inside. Jay Chan |
jaykchan
Oct 26
|
| yes, but will he know how to use any of them. |
Reginald
Oct 26
|
| Buy a hammer impact tool. And then make sure the socket you use does not
bottom on the case. That way you get twisting and an impact lengthwise at
the same time. Was the only thing that got aluminum screws out of a
Kawasaki engine case with out stripping the heads. |
Calif
Oct 26
|
| The one I have seen had reversed threads so as you screwed it in, it
unscrewed the bolt |
Reginald
Oct 26
|
| This is the type I was talking about. No hammer is used. The flutes of the
tool are deep enough that they grip without having to be forced into place.
http://www.mytoolstore.com/hanson/extractr.html |
JoeSpareBedroom
Oct 26
|
| Even dumber: Guys in college who didn't know how to operate a washing
machine. |
JoeSpareBedroom
Oct 26
|
| Stainless steel DOES react with aluminum but I am not sure what to do
about it. There is a material you can buy at marine stores to separate
ss parts from Aluminum but am not sure if this is used on bolts. |
Frogwatch
Oct 26
|
| No kitchen slave... just don't think our kids should be girliemen ,
like that California crowd. |
Don
Oct 26
|
| Wonder where he lives? Maybe he'd loan out those tools on occasion. |
Don
Oct 26
|
| It is called anti-seize. And the best for aluminum is Nevr-seize. |
Calif
Oct 26
|
| And how is he to be a manly man, when he can not man the BBQ? |
Calif
Oct 26
|
| >hammer. Anyway, it could not grab the bolt and could not spin the bolt
>out. I attempted to drill one of the broken bolt away. But this
>simply messed up the thread in one of the hole. Hey Jay. I know you like doing things yourself and that is totally
admirable - seriously. However, there are situations, like this one, where the best course of
action, in particular where you have an odd size or a chance that the
bolt may be chemically bonded with the housing, where a professional
it the only choice for doing a proper repair. Go to a machine shop, show them the situation and have them do it for
you. Not only cheaper in the long run, but it will be fixed right. |
Short
Oct 26
|
| I can teach him that..and already have. |
Don
Oct 26
|
| I have never used a grill in my life. I don't cook - the potential for disaster is enormous. :>) |
Short
Oct 26
|
| Actually, about 2,000 years ago, before we were so PC, at my Jr. High
School we had co-ed Home Ec. and Industrial Arts Classes. All of them
were electives and nobody was coerced into either class..... ..... we have NOT moved forward..... |
Gene
Oct 26
|
| In my high school, the hoodlums took home economics. We thought they were
weird. They were geniuses. That's where the food and the women were. |
JoeSpareBedroom
Oct 26
|
| Glad to hear you worked it out Jay. Sorry a non boat owner member here decided to flame you. But that is
his only reason he posts here. I would suggest you ignore him and any
*advice* he offers.. ;-) |
JimH
Oct 26
|
| LOL. Let me rephrase that: ......But this is his the only reason he posts here..... |
Oct 26
|
| Just who were you refering to here?? -W |
Clams
Oct 26
|
| Reggie. On the other hand, your contributions here are without question first class. I was just trying to be diplomatic without mentioning a name. |
Oct 26
|
| -W <unloads flamethrower... backs slowly out of the room> " JimH" <not telling you @ pffftt.com> wrote in message
news:VM-dnfPTwP5Eo9zYnZ2dnUVZ_u- |
Clams
Oct 26
|
| LMAO! |
Oct 26
|
| I know he can't be talking about me. My recommendation to find a good
shade tree mechanic to help learn the basics is a great one and did not
flame anyone. Marine engines are too expensive and too high tech. to do
on the job training. |
Reginald
Oct 26
|
| Take a look at a new water pump base for reference. I'll bet there aren't |
Ernest
Oct 26
|
| AWWWW! had to go and spoil all the guessin' fun by goin to the book!
Well good for you! At least you got to where you wanted to be. As for
the hogged out hole, this looks like an opportunity for "JBWeld to step
up to the plate. Clean the daylights out of that hole, I mean REALLY
clean it! Mix up enough of the A part, and B part to fill up the entire
threaded hole. (from your description it goes entirely thru the
casting?) if so that is great. Working from the BACK side of the
casting will guide you. After the JB sets drill in the EXACT CENTER
with a small pilot drill, 1/8 or smaller, then when satisfied you have
a good center, drill with the tap drill taking all the time you need. A
drill press would be handy for the previous steps. Hand tap then,
backing out very often, and try to pick up the original threads.
Carefully run your tap thru. As an afterthought somewhere I have LO
temp ALUMINUM stick, that I tried to use to plug a tank hole
unsuccesfully. Did melt the stick, but I did not have enough heat to
have it fuse to the sheet. Was using a propane torch. With your
casating you might have a similar problem. If there are better ways to
recover from the situation, we will soon hear about them. maybe
another member has a better recommendation Den 48tfYF |
den
Oct 26
|
| INCH-pounds. |
basskisser
Oct 27
|
| Yes, the one that is being shown in your link is exactly the type that
I have. If I understand you correctly, I am not supposed to use a
hammer on it; instead, I should have used it with a power drill and use
the extractor like a drill bit and run it in reverse. In other words,
the hardware store owner fooled me. Oh well... Thanks for the correction. Jay Chan |
jaykchan
Oct 27
|
| He didn't say anything like that. You just can't read can you? Did you
know that Homemaking courses teach a lot more than cooking? Do you
realize that Don never said anything like "women will be the kitchen
slave"? Do you realize that Don never said a man shouldn't know how to
cook? |
basskisser
Oct 27
|
| Yes, I brought the lower unit to a marine mechanic, and he will give me
a quote in the middle of next week for fixing the
messed-up-threaded-hole (and to remove the propeller that is really
stuck from day one). They are quite busy lately with winterizing and
putting boats in storage. Hopefully, I may be able to get it back in
the next weekend. Jay Chan |
jaykchan
Oct 27
|
| NO! You DO NOT use a drill! You drill into the bolt to make a space for this
tool. Then, you give the drill to your wife and instruct her not to let you
have it again until you're ready to drill the next bolt. I don't care WHAT
the hardware guy told you. If this is the tool you bought, he gave you the
wrong instructions. And, if this tool came in its original package, AND you
opened it carefully, you still have the instructions. Maybe your web browser options have been set to make simple instructions
invisible. Here's what I saw at that link: How to use a Screw Extractor to remove a broken bolt or screw from a hole:
First, drill a hole in the broken bolt. The correct drill size to use is
shown below and is also stamped on each Screw Extractor. Insert Screw
Extractor in the hole and, with a Tap Wrench, turn counterclockwise. The
Screw Extractor acts like a corkscrew. It grips into the sides of the
drilled hole and removes the broken part on its own threads without damaging
the threaded hole. |
JoeSpareBedroom
Oct 27
|
| OK. I mis-readulated it. |
JoeSpareBedroom
Oct 27
|
| Don *did* say something about "girlie men", though. Quite a few male chefs
would've had him hoisted onto the chopping block within seconds of hearing
that nonsense. |
JoeSpareBedroom
Oct 27
|
| You should have noticed my comment was directed at Colicky Bill.... not
at the male chefs of the world. |
Don
Oct 27
|
| Ok, Jay..... stop. Take a deep breath and THINK about what you are
doing. 1) First and most important thing is to READ *all* of the
instructions. Next, don't do *ANYTHING* until you *UNDERSTAND* the
instructions. 2)Second thing is that you need to realize how important it is to
develop a *feel* for what you are doing. To even suggest putting a
screw extractor into a drill screams the fact that you have no
understanding of the tactile feedback involved in the job. An
experienced mechanic doesn't strip bolts because he knows how removing
one should *feel*. This is the next thing you need to explore... or
you are constantly going to be fixing things that you have broken....
and you are constantly going to be breaking things..... |
Gene
Oct 27
|
| I don't have a new water pump base yet. I will get it next week. |
jaykchan
Oct 27
|
| Yes. Excellent question. However, I also agree with Frogwatch. You just have
to develop a feel for how much force things are able to take, and where the
gotchas are hiding. Try telling a 17 year old "With some screws, you want to
gently turn them in backwards until you feel or hear a click, or you'll
strip the threads". Mine said "Well, how do you know which screws?" I really
couldn't tell him, except to say that the higher the price of the thing
you're trying to fix, the more likely it is that you'll have a problem. :-) |
JoeSpareBedroom
Oct 26
|
| True story. In high school autoshop, yes we used to have those, the grounds
keepers for the sports field had their tractor in and were replacing a
muffler. The gardener asked how tight to make the nuts. Someone in the
class yelled out, "run it down until you hear a crack and then back of a 1/2
turn.". Everybody in the shop heard the crack as the U clamp broke. Class
went in to hysterics. |
Calif
Oct 26
|
| Not bolts...... I broke a head bolt on a Honda 50 when I was 12.....
not TWO head bolts. -W |
Clams
Oct 26
|
| I hate to say this, but from the questions Jay was asking in other
threads, it was obvious this would be the results. Since Jay likes to
do some of the basic work himself, he needs to find a shade tree
mechanic who will help him with some basics, such as telling the
difference between foot/lbs and inch/lbs. As long as he is doing "on
the job training" and is using rec.boats as his tutor, he will continue
to have problems. |
Reginald
Oct 26
|
| I wonder if he's using tools too large for certain jobs. I mean, sometimes
you just look at a bolt and you know if you use an extra large ratchet
handle (breaker bar??) as a substitute for more muscle, it's going to cause
problems. Or, you can't access a bolt at the correct angle and end up
stripping the head. My car mechanic actually likes having certain customers
hanging out nearby so when he's bitching about a stuck or inaccessible bolt,
he's got someone to complain to. This is where I learned that it often makes
sense to remove "thing #1" in order to get a better angle for removing
"thing #2", even if the manual says you shouldn't have to touch thing #1. More coffee.... |
JoeSpareBedroom
Oct 26
|
| There is no substitute for practice. |
jamesgangnc
Oct 26
|
| > Perhaps, but having a mentor prevents the hapless learner from
constantly reinventing the wheel. I have to agree with the posters in this thread that note that
something is lacking, here. A would be mechanic that starts with some
magic numbers gleaned from a book, and plugs them into a torque wrench
without any prior learning of the "feel" for what is necessary to
stretch a 1/4" bolt short of the breaking point is missing the "common
sense" equation of being a successful mechanic. I applaud Jay's interest and enthusiasm to explore being his own
mechanic, but he *really* needs a mentor to guide his practice. Local
community college? This is a *BIG* hot button for me, but this is endemic of no longer
teaching real Industrial Arts in our public schools. Higher education,
from mechanic programs, to engineering programs, to medical programs
all suffer from incoming students that have, in too many cases, never
even held a tool in their hands..... and in almost all cases, save
some rural areas, lack any real experience in using tools or in
dealing with the logic required of fixing everyday items that need
repair or adjustment..... |
Gene
Oct 26
|
| Now *that* was funny!! |
JohnH
Oct 26
|
| You got that right!
When my two sons were in jr high, they had to take homemaking courses
half the year and shop the other half. The pc crowd decided that the
girls whould have equal time hammering, cutting etc. while the boys
learned baking, etc.
I don't mind if the girls want to take shop, but don't force the boys
to be Suzy Homemaker unless they want to. |
Don
Oct 26
|
| There are few things more pathetic than a man who cannot project power in
the kitchen, especially if he's over the age of maybe 25. If the homemaking
courses were formulated by Emeril Lagasse, I'd be impressed. |
JoeSpareBedroom
Oct 26
|
| I tried that already. Either it didn't work or I went too easy on the
hammer. Anyway, it could not grab the bolt and could not spin the bolt
out. I attempted to drill one of the broken bolt away. But this
simply messed up the thread in one of the hole. Finally, a copy of the Mercury Service Manual arrived last night. I
read it and realized that the water pump base could be removed just by
removing 6 bolts, and each broken bolt went through a threaded hole in
the water pump base into another threaded hole in the lower unit. Seem
like the threaded holes in the water pump base had some chemical
reaction with the bolts, and the threads in the hole in the water pump
base had completely corroded away (the thread on the bolt mating with
the threaded hole in the water pump base was also corroded away
significantly and that was part of the reason why the bolt head broken
off easily before the thread got damaged by being over-torqued). In
other words, the water pump base was not holding on the broken bolt,
and only thing that was holding on with the broken bolt is the threaded
hole in the lower unit, and I can remove the water pump base easily.
After I had removed the water pump base, I could see a large section of
the broken bolt sticking out in the open, and I easily removed them
using a channellock plier. Is this a happy ending? Not really. In the attempt of drilling out
one of the broken bolt, I ended up messing up the thread in one of the
hole in the lower unit (the other three are fine). I don't know what
is the best way to deal with this. I will bring the lower unit to a
marine mechanic in this afternoon to see if he can help. The other thing is that I can simply replace the water pump base and
the broken bolts, and this should take care of the corroded threaded
holes in the water pump base. But I am wondering why the holes and the
bolts can get so corroded. The bolts must be stainless steel, right?
I didn't know that stainless steel bolts can react to casted alumimum
lower unit. How should I prevent this problem from happening again?
Any idea? Thanks. Jay Chan |
jaykchan
Oct 26
|
| Hammer???????? |
JoeSpareBedroom
Oct 26
|
| As mentioned in my other reply, I have removed the broken bolts by
simply removing the water pump base. And I also attempted to drill out
the broken bolt; but I could not get the drill bit to center on the
bolt because the bolt was sunk inside the hole and I could not see the
surface of the bolt that well. This ended up messing up the thread of
the hole. Hopefully, the heli-coils will fix this problem. Thanks. Anyway, I will bring the lower unit to a marine mechanic later in this
afternoon, and I will see how he will fix the thread in the hole. Jay Chan |
jaykchan
Oct 26
|
| Thanks for the tip of selecting the right kind of drill bit. Although |
jaykchan
Oct 26
|
| Actually, I could have broken all four -- instead of merely three. I
must have come to my sense when I was bearing down on the 4th bolt. I have a tendency to over-doing anything (such as running my knee to
the point that I needed to have a surgery done on my knee). And
tightening up the bolts too much is one of my tendency. That was the
reason why I bought a torque wrench hoping that using the torque wrench
will prevent me from over-torquing the bolts. Unfortunately, I mistook
60-inch-pounds with 60-feet-pounds, and I ended up over-torquing the
bolts by 12 times. And the fact that the torque wrench that I use is
quite big (designed more for higher torque such as for torquing the
propeller); therefore, I didn't get a good feel of the tension. I have
ordered a 1/4" torque wrench that is designed for lower torque (such as
60-inch-pounds); hopefully, this will prevent me from making a similar
mistake. Jay Chan |
jaykchan
Oct 26
|
| 1/4" for 60 ft lbs.....hang on a minute. Who makes a 1/4" drive wrench with
60 *FOOT* lbs in its range? |
JoeSpareBedroom
Oct 26
|
| Call around to hardware stores and ask if they sell spiral screw extractors.
Before you jump in the car, measure the diameter of the bolt shafts you need
to remove. And, if you know the socket size that fits the heads, write that
down too. |
JoeSpareBedroom
Oct 25
|
| :I over-torqued four bolts in the lower unit of an outboard, and the
:heads of three bolts broke off. I managed to remove one of the broken
:bolt using a Dremel tool and a diamond grind bit. But I cannot remove
:the other two broken bolts using the Dremel tool. Based on the past
:posts in this newsgroup, I learn that the best option in this situation
:is to drill out the broken bolts. I would like to learn the details of
:the way to drill out the broken bolts. My question is: :Which size of drill bit do I need? Should it be as large as the hole
:where the broken bolt is? The best way to do this is to get a selection of left-handed drill
bits. These have the twist going the opposite way from a normal twist
drill. You have to run your drill in reverse to drill a hole with one
of these. That means, in addition to puting a hole in the bolt, you
apply some anti-clockwise force to the bolt, which may back it out.
Start with a small bit; drill exactly in the center, exactly
perpendicular to the hole. Then move up to a bigger bit, and repeat.
Increase the size of the bit until you're using a bit the size of the
minor diamter of the bolt (the diameter of the round part of the
bolt, minus the threads.). Then you can use a pick to pick the
threads from the bolt out of the threads in the hole. You could also
drill a hole, and try an EZ-out. There's a better description here:
http://www.dimebank.com/tech/BrokenBolt.html :Related questions: : The bolts are for securing the water pump housing for the
:impeller. The hole for the bolt is at the edge of the water pump base
:-- meaning that one side of the hole is kind of thin -- something like
:3/32" thick. The bolt itself is like 1/4" or slightly larger. Because
:I have over-torqued the bolts, I found that the holes pretty much losed
:most of the thread. If I drill out the bolts, I probably will find
:that the holes will become even larger. If I re-thread the hole after
:drilling out the bolts, I am afraid that the holes will be even larger.
: I am afraid that there will not be enough metal left. Is my
:estimation correct? I am wondering whether I may be better off somehow
:pouring in new metal into the holes and drill new holes instead of
:rethreading/enlarging the existing holes? There are thread inserts, called heli-coils (that's the brand name of
the original, and best, there are others), that may solve this problem
for you. The hole needs to be drilled oversize, roughly to the major
diamter of the hold hole, and then it's tapped for the insert. The
insert is a coild of wire that allows the use of the original sized
fastener. David |
David
Oct 25
|
| If he's worried about how much metal is left then helicoils are
probably out of the question. The most important thing is to try very hard to drill down the center
of the remaining bolt. It helps to grind the top flat and center punch
before drilling. The surrounding metal in this case is far softer than
the bolt so getting off center will be a big problem. Sometimes it is hard to use easy outs on smaller bolts because they
tend to spread the bolt material out further jaming it in the hole. Sometimes I've been able to find a metric size that is slightly bigger
than the american size and tap the hole to the metric size
successfully. This is usually closer than the next size up america
size. It is pretty hard to get anything into the hole to replace missing
metal since I'm thinking you are working with cast aluminum. If it
gets that bad then maybe securing threaded studs into the holes with
epoxy might be worth a try. Particularly if there is some thread left.
Then use nuts to secure the water pump. |
jamesgangnc
Oct 25
|
| >heads of three bolts broke off. I managed to remove one of the broken |
Gene
Oct 25
|
| I wanna know how you broke *three*.
I mean - after you broke one... didn't a clue rake at least try to hit you
over the head about the rest of them? -W
<jaykchan@hotmail.com> wrote in message |
Clams
Oct 25
|
| He broke the first two ... first. Eisboch |
Eisboch
Oct 25
|
| I was wondering the same thing. ;-) |
Oct 25
|
| I know this because it's something I would do . Kibosh |
Eisboch
Oct 25
|
| Not to jump on the jump-on-Jay bandwagon (he's got enough trouble with his
broken bolts already), but wasn't he the guy who asked what the difference
is between foot pounds and inch pounds a while back? |
Ernest
Oct 25
|
| Good Lord, give him credit for trying to do his own work. So he makes
expensive mistakes, I bet he learns from them. I have managed to break
5 drill bits in rapid succession.
Now, If I remember, there are special tools for removing broken bits or
taps. I suggest he look into a tool catalogue such as McMaster-Carr or
MSC. |
Frogwatch
Oct 25
|
| I have several tiny hardened end mills from MSC. They are no wider
than a screwdriver blade and cost about $20 each and I have used them
for such tasks to get down into a bolt hole (using the dremel tool) to
make a screwdriver slot. You can also use the tiny diamond burr with
th dremel to make a "dent" atop the broken bolt for the drill bit to
start on when you drill it out. |
Frogwatch
Oct 25
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