broken bolt broken screw extractor ... what next?

[WI Dan]

Toro recycler mower. Main handle mounting bolt broke. I drilled a hole, stuffed in a screw extractor, and promptly broke it off. I tried re-drilling and grinding but I'm not making progress. Can't access from the backside. I think the deck is cast aluminum (softer than the bolt). The screw extractor seems to be harder material than the bolt. I tried punching it clockwise but it wont' dislodge from the hole. I tried drilling new holes along side it, but I keep breaking drill bits and risk wandering into the threaded portion of the aluminum.
I dunno what to try next? I have limited tools but always interested to buy more!

 

[used red MN]

Have a machine shop turn you a centering bushing that the OD will fit in the hole in the metal piece. Maybe two, one for a bit a couple sizes bigger then the off center hole you already have drilled. Then a second a size or two under the specified drill bit size for the tap of the broken off bolt. You may have to but some good bits, like ones that cost $12 to $20 each.

 

[DoubleO7]

Toro recycler mower. Main handle mounting bolt broke. I drilled a hole, stuffed in a screw extractor, and promptly broke it off. I tried re-drilling and grinding but I'm not making progress. Can't access from the backside. I think the deck is cast aluminum (softer than the bolt). The screw extractor seems to be harder material than the bolt. I tried punching it clockwise but it wont' dislodge from the hole. I tried drilling new holes along side it, but I keep breaking drill bits and risk wandering into the threaded portion of the aluminum.
I dunno what to try next? I have limited tools but always interested to buy more!

I am guessing the handle itself is out of the picture?

If it is, and it is steel, I would just weld a tab to the handle on each side and the other end of the tabs would have a hole in them so that I could utilize those other two bolts in the picture.

Or does the handle have to pivot around that broken bolt?

 

[WI Dan]

I am guessing the handle itself is out of the picture?

If it is, and it is steel, I would just weld a tab to the handle on each side and the other end of the tabs would have a hole in them so that I could utilize those other two bolts in the picture.

Or does the handle have to pivot around that broken bolt?

Yes, the handle is barely visible in the upper left of the first photo.
Yes, the handle pivots on that bolt. It's beefy, the smaller bolt to the left isn't strong enough.
Thanks for the idea.

 

[WI Dan]

Have a machine shop turn you a centering bushing that the OD will fit in the hole in the metal piece. Maybe two, one for a bit a couple sizes bigger then the off center hole you already have drilled. Then a second a size or two under the specified drill bit size for the tap of the broken off bolt. You may have to but some good bits, like ones that cost $12 to $20 each.

I didn't think of a centering bushing. Good idea.
The bolt is pretty much flush with the face of the hole...I'll have to clamp it on there.
So - what kind of drill bit should I look for? HSS, cobalt, titanium coated?

 

[BarnyardEngineering]

Screw extractors are made from an extremely hard steel alloy. Harder than high speed steel drill bits. Harder than carbide drill bits. You're not going to drill it out.

What you can do is drill AROUND the extractor, using a tiny diamond hole saw that you can get at Lowes. Lots cheaper than paying a machine shop to remove the extractor, which can run you hundreds of dollars.

 

[WI Dan]

Screw extractors are made from an extremely hard steel alloy. Harder than high speed steel drill bits. Harder than carbide drill bits. You're not going to drill it out.

What you can do is drill AROUND the extractor, using a tiny diamond hole saw that you can get at Lowes. Lots cheaper than paying a machine shop to remove the extractor, which can run you hundreds of dollars.

Thank you for this. you confirmed what I was kinda thinking.
I'll give it a shot.

 

[Mule Meat]

Remove the handle completely and the metal bracket.

If I am thinking correctly. The bolt that holds the handle has or had a plastic "star" shaped knob. If so. I believe that a nut is used for the bolt and is held in place by a bracket.

If this is the correct setup. . Just remove the bracket and the clip and the nut should fall out or can easily be tapped out with a punch.

 

[37chief]

Toro recycler mower. Main handle mounting bolt broke. I drilled a hole, stuffed in a screw extractor, and promptly broke it off. I tried re-drilling and grinding but I'm not making progress. Can't access from the backside. I think the deck is cast aluminum (softer than the bolt). The screw extractor seems to be harder material than the bolt. I tried punching it clockwise but it wont' dislodge from the hole. I tried drilling new holes along side it, but I keep breaking drill bits and risk wandering into the threaded portion of the aluminum.
I dunno what to try next? I have limited tools but always interested to buy

If you have a cutting torch try blowing the extractor out if it isn't t too deep. The heat may help loosen the broken bolt. If you are quick the aluminum should be fine. stan

 

[DaveBN]

For future reference what you should have was drilled that bolt out using progressively larger left hand drill bits. From my experience screw extractors are useless.
Dave

 

[Janicholson]

Thank you for this. you confirmed what I was kinda thinking.
I'll give it a shot.

The bushing idea and a hole saw that is just bigger than the steel of the twisted bolt. This allows the hole saw to cut aluminum only. It cannot be centered because the center drill of the hole saw will be destroyed by the easy out. but the bushing will center the hole saw. Then use a thread insert to repair the threads. (not Helicoil) Jim

 

[BarnyardEngineering]

The bushing idea and a hole saw that is just bigger than the steel of the twisted bolt. This allows the hole saw to cut aluminum only. It cannot be centered because the center drill of the hole saw will be destroyed by the easy out. but the bushing will center the hole saw. Then use a thread insert to repair the threads. (not Helicoil) Jim

The <1" diamond hole saws don't have center drills anyway.

Last time I tried an EZ out, it broke off in a 3/8" bolt. Got a 3/8" diamond hole saw. It followed the EZ out right down into the casting. The casting was hollow so the plug is still rattling around in there somewhere. Threaded the resulting hole for 7/16", since the bolt size wasn't critical. Threads weren't great but they were good enough for a battery tray on a Farmall Cub. If three don't hold it, four never would have.

 

[MarkB_MI]

If a steel fastener won't easily come out of an aluminum casting, you need to use heat. Heating the fastener will break the bond between the fastener and casting. Even after breaking the bolt, you had a decent chance of getting it out with a little heat. And that's still your best bet. The old trick of welding a nut to the broken bolt might work for this reason.

You're not going to be able to drill out the easy-out. You might be able to grind it out with a carbide burr in a die grinder.

 

[Brown David]

For future reference what you should have was drilled that bolt out using progressively larger left hand drill bits. From my experience screw extractors are useless.
Dave

I've always wondered what makes people think an extractor will turn out a bolt that has been broken off due to trying to remove it when it's seized in it's hole.


If the seized full sized bolt broke, how is a smaller, more brittle extractor going to do it?

 

[RESLLS]

Take off the steel bracket, weld a flat washer with the same size hole as the bolt to the broken bolt. The weld a nut to the flat washer.

 

[Old560]

Toro recycler mower. Main handle mounting bolt broke. I drilled a hole, stuffed in a screw extractor, and promptly broke it off. I tried re-drilling and grinding but I'm not making progress. Can't access from the backside. I think the deck is cast aluminum (softer than the bolt). The screw extractor seems to be harder material than the bolt. I tried punching it clockwise but it wont' dislodge from the hole. I tried drilling new holes along side it, but I keep breaking drill bits and risk wandering into the threaded portion of the aluminum.
I dunno what to try next? I have limited tools but always interested to buy more!

Easier to just throw it away and go buy a new mower, then sit on the couch.

 

[WI Dan]

I've always wondered what makes people think an extractor will turn out a bolt that has been broken off due to trying to remove it when it's seized in it's hole.


If the seized full sized bolt broke, how is a smaller, more brittle extractor going to do it?

Both of you are confirming what I learned on this project. It was my first time trying to deal with a problem like this. Now I know better. I won't try this method again.

 

[WI Dan]

Remove the handle completely and the metal bracket.

If I am thinking correctly. The bolt that holds the handle has or had a plastic "star" shaped knob. If so. I believe that a nut is used for the bolt and is held in place by a bracket.

If this is the correct setup. . Just remove the bracket and the clip and the nut should fall out or can easily be tapped out with a punch.

Unfortunately, that's not the design of this particular mower.

 

[Fritz Maurer]

Need to take it to a welder. You’re already beyond any more drilling once the first attempt gets off-center … the next drilling will follow the original hole. The bushing idea would work only if you have an end mill, which doesn’t require a center. Even then, it will work only to the depth of the broken ez out. I really feel welding is your last option… and get yourself a heli-coil kit, as there will be nothing left of those threads but white powder.

 

[WI Dan]

If you have a cutting torch try blowing the extractor out if it isn't t too deep. The heat may help loosen the broken bolt. If you are quick the aluminum should be fine. stan

No torch...bummer.