What is the best bit for drilling out broken bolts?

What is the best bit for drilling out broken bolts?

Joined: May 9th, 2005, 7:25 pm

March 14th, 2008, 8:24 pm #1

I was removing the rear axles in my old Honda CRV when I broke a bolt.

Bolt #31 (the lower one) is pretty long. It's pointed on the end.


I had already worked on the left side and found that bolt was really hard to get out.
It was covered in rust dust.. When I got to the right side, it felt like it was coming out,
but then snapped in half.





The bolt had an OD of about 0.39" and 3.15" long.
(90173-SR3-003 BOLT, ARM TORQUE (LOWER) (10X80)

So, the metal must be pretty hard, what is the best kind of bit to use?
Everything I have on hand is regular high speed steel.

What is left of this bolt is SO tight, I don't see anyway that an Easy-Out would work.

Any drilling tips would be appreciated.

TIA,
Rich
Last edited by RLT59 on March 14th, 2008, 8:34 pm, edited 1 time in total.
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Joined: May 24th, 2003, 1:33 pm

March 14th, 2008, 10:41 pm #2

When working on a car penetrating oil is your best friend.When working on any suspension parts i always spray the bolt a couple of times about 24 hours before working on them.Cobalt or carbide will work,just buy a good brand of drill bit.Center punch the bolt
and start small so you can make sure to keep the hole centered.Do not drill the hole too big or when you try to easy out the bolt it will force the threads into the nut and jam.Use a torch on the nut when you go to remove the bolt,it will expand the nut a little.
I have 4 or 5 sets of easy outs and the square ones work the best for me.I have had to drill the bolts out to the threads of the nut
and use a small pick or punch to remove what was left.
I just finished putting a timing belt kit in my accord,now to the
axles and wheel bearings.Good luck and hide the big hammers.LOL.
Mark
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Joined: September 27th, 2003, 4:35 am

March 15th, 2008, 12:11 am #3

I was removing the rear axles in my old Honda CRV when I broke a bolt.

Bolt #31 (the lower one) is pretty long. It's pointed on the end.


I had already worked on the left side and found that bolt was really hard to get out.
It was covered in rust dust.. When I got to the right side, it felt like it was coming out,
but then snapped in half.





The bolt had an OD of about 0.39" and 3.15" long.
(90173-SR3-003 BOLT, ARM TORQUE (LOWER) (10X80)

So, the metal must be pretty hard, what is the best kind of bit to use?
Everything I have on hand is regular high speed steel.

What is left of this bolt is SO tight, I don't see anyway that an Easy-Out would work.

Any drilling tips would be appreciated.

TIA,
Rich
just make sure you let the threaded bolt soak a little with penetrating spray and go slow, make sure it has a good bite!http://www.sears.com/shc/s/p_10153_12605_00952154000P
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Joined: May 8th, 2001, 4:06 pm

March 15th, 2008, 1:14 am #4

When working on a car penetrating oil is your best friend.When working on any suspension parts i always spray the bolt a couple of times about 24 hours before working on them.Cobalt or carbide will work,just buy a good brand of drill bit.Center punch the bolt
and start small so you can make sure to keep the hole centered.Do not drill the hole too big or when you try to easy out the bolt it will force the threads into the nut and jam.Use a torch on the nut when you go to remove the bolt,it will expand the nut a little.
I have 4 or 5 sets of easy outs and the square ones work the best for me.I have had to drill the bolts out to the threads of the nut
and use a small pick or punch to remove what was left.
I just finished putting a timing belt kit in my accord,now to the
axles and wheel bearings.Good luck and hide the big hammers.LOL.
Mark
the easy out will work because the size of the bolt will be a little smaller after you drill out the center, hence not stuck in there so tight. Sometimes have to drill out most of the center to get it to work that way, though. Good advice too about penetrating oil. I've had bolts take several doses over several days before they finally started to loosen up a little.
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Joined: September 10th, 2001, 4:33 pm

March 15th, 2008, 3:06 am #5

I was removing the rear axles in my old Honda CRV when I broke a bolt.

Bolt #31 (the lower one) is pretty long. It's pointed on the end.


I had already worked on the left side and found that bolt was really hard to get out.
It was covered in rust dust.. When I got to the right side, it felt like it was coming out,
but then snapped in half.





The bolt had an OD of about 0.39" and 3.15" long.
(90173-SR3-003 BOLT, ARM TORQUE (LOWER) (10X80)

So, the metal must be pretty hard, what is the best kind of bit to use?
Everything I have on hand is regular high speed steel.

What is left of this bolt is SO tight, I don't see anyway that an Easy-Out would work.

Any drilling tips would be appreciated.

TIA,
Rich
What everyone else has said plus use SiliKroil penetrating solvent its great for rusted and frozen fasteners.
SiliKroil gets into places you wont believe.
Doug
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Joined: October 14th, 2003, 4:56 am

March 15th, 2008, 10:50 am #6

I was removing the rear axles in my old Honda CRV when I broke a bolt.

Bolt #31 (the lower one) is pretty long. It's pointed on the end.


I had already worked on the left side and found that bolt was really hard to get out.
It was covered in rust dust.. When I got to the right side, it felt like it was coming out,
but then snapped in half.





The bolt had an OD of about 0.39" and 3.15" long.
(90173-SR3-003 BOLT, ARM TORQUE (LOWER) (10X80)

So, the metal must be pretty hard, what is the best kind of bit to use?
Everything I have on hand is regular high speed steel.

What is left of this bolt is SO tight, I don't see anyway that an Easy-Out would work.

Any drilling tips would be appreciated.

TIA,
Rich
I hate that...

Looks like it may be an easy drill-out job from looking at the assembly and where it broke off in the hole. Appears to be a welded on nut that the bolt goes into(?)

You seem to have broken the bolt off far enough below the surface so that you have created a handy 'drill bushing' to start your drill into the bolt on center with.

If I had this situation (and I understand it correctly), I'd get a drill the same size as the bolt and drill it straight through, nut and all if you can keep it straight. Then use a new bolt long enough to go past the original welded on nut, and put another nut on top of it to hold the bolt in.

Another option (if you can get at it) is to cut the welded nut off with a small abrasive wheel and punch the remainder of the bolt out of the hole.

I wouldn't try a solid carbide bit - even one that size is easy to snap with a hand drill. I'd go with cobalt.

An "easy" out? (they should be called "maybe" outs). All I can say about that method on a tight bolt that size is....I wish you luck.
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Joined: May 9th, 2005, 7:25 pm

March 15th, 2008, 2:09 pm #7

I was removing the rear axles in my old Honda CRV when I broke a bolt.

Bolt #31 (the lower one) is pretty long. It's pointed on the end.


I had already worked on the left side and found that bolt was really hard to get out.
It was covered in rust dust.. When I got to the right side, it felt like it was coming out,
but then snapped in half.





The bolt had an OD of about 0.39" and 3.15" long.
(90173-SR3-003 BOLT, ARM TORQUE (LOWER) (10X80)

So, the metal must be pretty hard, what is the best kind of bit to use?
Everything I have on hand is regular high speed steel.

What is left of this bolt is SO tight, I don't see anyway that an Easy-Out would work.

Any drilling tips would be appreciated.

TIA,
Rich
I'm not feeling so depressed this morning, after a mere 3 hours of sleep last night.

Victor, that "cut the welded nut off with a small abrasive wheel" is starting to sound real good..
I was not able to get a real close look at the 'nut' end yesterday, just reached up there to put
a guide pin in there, during re-installation.

I think there are some 10x115mm bolts around that might fill the bill, if there is really a nut
that can be sawed off..

Once it stops snowing here, I'll get out there and take a look..
If there is a nut welded on the back, that would save me a TON of drilling..

I still remember the nightmare of breaking a neighbor's 3/8" Cobalt bit while trying to
remove rusted exhaust pipe clamps on an old 1977 Mazda. It was going great, then 1.2 micro seconds later, SNAP!



Cheers,
Rich

Edit:
It's cold out, but I got a few pics.

This looks like a thin wall treaded sleeve. Maybe not too hard to cut off.


But, that shield thing on the right side is blocking access of the cut-off tool..
Maybe if I can find some larger diameter wheels, I can reach in there.
I'm not sure if I can remove that shield tab. It feels real solid.


If I could do the cut, with the shield in place, (and reach bottom)
I would then have to hammer the stud out and cut it off again,
until fell out.

Edit2:
The shield came right out with one bolt. It was on the inside.

I found a nice long bolt with the exact same OD (9.9mm).


There were a couple of those extra long bolts holding up the 4x4 rear differential.
So, when I get the broken bolt out and the new one installed, I'll be driving a FWD..


I need to check ACE to see if they have any suitable metric nuts..
And then it's going to be time to dig out the cut-off wheels.

Last edited by RLT59 on March 15th, 2008, 10:47 pm, edited 1 time in total.
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Joined: October 14th, 2003, 4:56 am

March 16th, 2008, 10:13 am #8

Don't forget to clean up that pool of blood when you're done
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Joined: May 9th, 2005, 7:25 pm

March 17th, 2008, 2:02 pm #9

First, I have to get the stuck bolt out..

After I cut off the head, it was still stuck..
So started drilling and grinding alway at the welded flange.
It stayed stuck So I drilled into it so deep that the arm finally fell out.


BUT the bolt was still stuck!!!

Here is the backside after I ground it concave with a 1" wheel,
And hammered the crap out of it.


The only thing I can figure is, the (10mm ID)steel tube inside the rubber bushing
has completely rust-bonded with the (9.9mm) bolt.

Today, I may go see about getting a bigger hammer..


----Edit-----
Got a 2.5 pound hammer yesterday and had no luck with it. Now I'm trying "PB Blaster" to see if
it's any better than Gunk Liquid Wrench..
Maybe today I'll warm it up a little with a heat gun, then spray it, as it cools..
I was thinking about buying a big C-clamp to try to press out the part, but I found that
my big drill press vise can be used. No luck so far..
Last edited by RLT59 on March 18th, 2008, 1:01 pm, edited 1 time in total.
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Joined: May 24th, 2003, 1:33 pm

March 18th, 2008, 1:34 pm #10

I thought i was the only one who had that kind of bad luck.Had the same trouble with both upper a arms and lower arm and dampening fork.The bolts rust in the metal sleeves and become one.You might try and call a junk yard and see if you can find the parts used.I bought a rolled accord for $200 and have spare parts for everything.After stripping the car i sold it for $200 to the junk yard.
Mark
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