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Author Topic: drilling a grade 8 bolt.  (Read 1383 times)

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Offline Gurp

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drilling a grade 8 bolt.
« on: October 21, 2019, 08:58:08 AM »
I broke a grade 8 bolt in my shadow mointing the fender struts. It was my fault i was in a hurry starting to rain and I didnt run the tap all the way through... so far ive dulled 3 drill bits and 2 uni bits.

suggestions...
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Offline 754

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Re: drilling a grade 8 bolt.
« Reply #1 on: October 21, 2019, 09:05:21 AM »
Run the drills slower. Once you over speed it and dull the edge, it can't get better.
 Use a left hand bit if you can.
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Offline scottly

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Re: drilling a grade 8 bolt.
« Reply #2 on: October 22, 2019, 08:58:17 PM »
Quote from: Gurp on October 21, 2019, 08:58:08 AM
I broke a grade 8 bolt in my shadow mointing the fender struts.
There is no such thing as a grade 8 bolt in the metric world. Do you mean a stock type Honda bolt with an "8" on the head? The 8 is a manufacturers mark, not a grade mark. ;)
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Offline 70CB750

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Re: drilling a grade 8 bolt.
« Reply #3 on: October 23, 2019, 03:56:31 AM »
Get what they call cobalt bit at Home Depot or Lowes.
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Offline Gurp

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Re: drilling a grade 8 bolt.
« Reply #4 on: November 01, 2019, 01:19:40 PM »
Quote from: scottly on October 22, 2019, 08:58:17 PM
Quote from: Gurp on October 21, 2019, 08:58:08 AM
I broke a grade 8 bolt in my shadow mointing the fender struts.
There is no such thing as a grade 8 bolt in the metric world. Do you mean a stock type Honda bolt with an "8" on the head? The 8 is a manufacturers mark, not a grade mark. ;)

I had bought the bolt at the hardware store.
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Offline Gurp

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Re: drilling a grade 8 bolt.
« Reply #5 on: November 01, 2019, 01:20:33 PM »
Thanks for all the suggestions I'll have to check Lowe's for one of those I haven't tried a left-handed bit yet I've been going slow and small but just haven't made a lot of ground against it I'm home for the weekend again so I'll try to give it a go
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Offline Nicklopic

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Re: drilling a grade 8 bolt.
« Reply #6 on: November 01, 2019, 02:40:04 PM »
its probably a little too late depending on how far you've drilled but did you try welding a nut to the broken bolt? that's my favorite and go to way whenever possible. even when broken flush or a little recessed, a little build up, then burn the nut to the build up. sometimes it takes a few tries but ive done it on a number of different fasteners.
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Offline Tracksnblades1

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Re: drilling a grade 8 bolt.
« Reply #7 on: November 01, 2019, 03:12:07 PM »
What size bolt is it? Broken off in sliders (aluminum) ?
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Offline Don R

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Re: drilling a grade 8 bolt.
« Reply #8 on: November 01, 2019, 03:18:15 PM »
 I've done the weld trick Nick mentioned. It works, may require a few tries but the heat and grip works wonders.
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Offline Gurp

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Re: drilling a grade 8 bolt.
« Reply #9 on: November 03, 2019, 04:07:33 PM »
It broke below flush so i couldnt do the weld trick to start.
its broke in the frame above the axle hole.
On my vt600. I'll have to take a pic when i get a chance
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Offline demon78

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Re: drilling a grade 8 bolt.
« Reply #10 on: November 03, 2019, 06:58:16 PM »
I would go after the Cobalt bit rather than the Titanium bit I have had much better luck to the point of replacing broken bits with Cobalt as S.O.P. 
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