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Guide to Easyout use for broken bolts

Discussion in 'Technical and Troubleshooting Torque' started by gegvasco, Jul 30, 2007.

  1. I was installing some Givi crash bars to the V-Strom on the weekend and found out the hard way that the bolts supplied with the crash bars are not up to strength to take the torque required by the bike's service manual. The manual said torque to 25.5 ft pounds so to be safe I set the torque wrench to about 23. And the f%^&ing thing still sheared! It has sheared about half way along when it was almost the whole way in so there is no way to get to what's left to grab a hold by any other means. The bolt is 1 of 8 engine mounting bolts and after some more research on the net I read some conjecture about 16 ft pounds being correct despite the manual requiring 25.5. So I torqued the other 7 bolts to 16 with no problems.

    So now I have 2 problems. Obviously I have a sheared off engine mount bolt. I'm guessing because it is all the way in it is probably doing it's job in supporting the engine but is doing nothing to hold the crash guard on(it is one of 4 holding that side on). So I need to work out how to remove it. I have done a search and it seems an Easyout is the go. Being a mechanical newbie I'm not exactly sure which one I need.

    So the first question is for an M8x35 bolt, what diameter Easyout do I need? I take it 35 is the length in mm and 8 is the thread width in mm? If so, what Easyout is required to work this bolt.

    The second problem and hence question is that I obviously need at least 1 new bolt and there is no way I'm going to get another Givi bolt. But if the bolts that I did put in are only torqued to 16 ft pounds, should I be concerned that the manual requires 25.5? If so then I might as well buy some high tensile(up to 100ft pounds?) bolts and replace all 8.

    Any thoughts? I'm also interested to know if there are any tricks to using the Easyout to ensure it doesn't break as well!
  2. G/day Mate , i have easy outs etc if needs be come up and ill get it out for you .

    Cheers Bob
  3. I've never broken an Easy-out, so I wouldn't worry about that. But I'd pull ALL of them out and do the 'hi-tensile steel replace' thing, that's for sure!
  4. I've broken easy outs, but I was asking a lot of them.
    Greg, you should try a few things as well as the easy out. Start soaking that bolt with penetrating oil immediately, it wil really help get it out.
    When using the easy out, centre punch the bolt, and start with a small drill, it is much easier to get the hole centred. If you have an industrial supply or machining supplies place nearby, see if you can get a reverse twist drill for the bolt. Often, just using a reverse drill will move the bolt out.
    When using an easy out, I try to drill the very largest hole I can in teh bolt, so I can use the largest easy out I can get in there ( so they don't break).
    You can buy cheap sets of easy outs from auto parts stores, you get four or five different sizes.

    Regards, Andrew.
  5. me too, dropped the damn drill :oops:
  6. Thanks for the info and to Bob for the offer. I have purchased a set of easy outs and hunted around a couple of stores for the right bolts. Easier said than done! Bunnings had M8x35s but not in high tensile. Repco had high tensile but not in M8x35. Seems all the Repco stores only go up to M8x25 in HT. So had to order some in. So hopefully I will be having a crack at it on the weekend if they come in by then.

    Now, to find a powerpoint in the underground apartment garage!
  7. Try your local bolt and fastener shops.
    Just drive around your local industrial lot and find it, I swear, those places must be mandatory for industrial lots... And they can usually tell you where to go ( :LOL: ) if you can't find it.
  8. Well, SUCCESS!!!!!!!

    First hurdle was getting power. In the apartment block carpark that takes up almost a full block and has about 120 spaces, there was 1 powerpoint and it wasn't live!!! Luckily my balcony on the second floor looks over a very quiet side alley so after stringing 3 extension cords together and making use of seom very rudimentary rope throwing skills I managed to turn the alley into a workshop and get the drill going.

    The bolt had snapped off about halfway in at about 20 foot pounds of torque(the after shot compared to an intact bolt):

    I went out and bought a set of "Easy-outs" as they are called here or officially "Extractor screw set" which were about $80. The extractors sizes are 1 to 5 from right to left and the corresponding pilot hole drill bits are on the left.

    Although the extractor set was Imperial and the bolt was 8mm metric, the size 3(5/16") extractor was only a fraction smaller than what was required for an 8mm bolt. So I figured this added a little margin for error. I bought a centre punch and marked the centre of what was left of the bolt. It was just about impossible to get the exact centre because the way the bolt had sheared, it was an uneven surface and when striking the centre punch it slipped off centre. But it was pretty close. I initially used the size 2 pilot hole drill just to get the hole going and to try to drive the hole more towards centre. Once I had drilled in about 7mm, I changed to the correct size 3 pilot drill bit and drilled in about 12mm. This is what the pilot hole looked like in the end:

    I then inserted the size 3 extractor into the pilot hole by hand. I had read on the internet that because the extractors need to be extremely strong, they are very brittle and that if you were to snap one in the bolt, you are totally screwed(excuse the pun). SO I was very careful with the next step. Once the extractor gripped under finger pressure, I then got an adjustable spanner and very slowly turned it in(anti-clockwise of course). It took about 1/2 a turn with increasing resistance before I felt the loctite on the bolt give and then a constant pressure as the bolt unwound out. SUCCESS!!!!!

    To avoid a similar problem when rebolting, I did some research on tensile strength of bolts and worked out that the 8.8 rating bolts supplied are about 1/2 way along the scale of tensile strengths available. You can tell what tensile strength the bolt is by looking at the head - the rating is written on the bottom with the manufacturer on the top. There are higher tensile strengths of 10.9 and 12.9 so I went shopping and managed to order in some 12.9 M8x35 Socket head cap screws(the official nomenclature). It was about $20 for 12. I reckon you could have given me a heart attack just by clapping as I was torqueing the first of these bolts to the required torque. But the 12.9 bolts were up to the task and I subsequently replaced all 8 engine mounts bolts, which are now torqued to the specified amount.
    • Like Like x 2
  9. The other trick is forgetting to reset your torque wrench after each screw. You can accidentally torque one up, go onto the next and not get any warning you have passed the correct torque until it *snaps*. This is especially easy to do with smaller screws as it is harder to judge by hand that you have gone too far with the massive handle on the wrench. I have taken to pinching smaller screws up by hand with a socket and small drive rather than with a massive torque wrench.
  10. Greg,

    Top effort mate - I wish NR had a personal archive facility, I'd save this thread as an easyout instruction manual.

    There's some great help on NR isn't there! I had my own easyout thread a while back and it saved my bacon.

    Anyways, the bolt failure you have looks like a thread cutting defect causing a crack under load. It will be hard to exactly confirm now since the evidence is all but obliterated... anyway, it's only of academic insterest isnt it.

    You're right to assume that a bolt shouldn't fail like that mate.

    Can I suggest you send the pics to Givi and if they are any kind of ISO quality company, they'll ask their bolt supplier to explain and look into it. They might even ask for the bolt!... maybe give you something for your pain and effort... never know.

    Thanks for sharing the experience man.
  11. Ditto to everything Rob, said, mate, a top effort and a definitive explanation of the solution. Well done :).
  12. I've had a cheap and nasty easy out set for over 20 years, and touch wood, never had to use them.

    Top effort gegvasco, especially on working in a less than ideal environment :cool:
  13. Something to bear in mind that no-one's mentioned so far: you should never torque bolts dry. Always use some lubricant - assembly oil/grease, anti-sieze whatever. Can make a HUGE difference to the actual reading.

    • Informative Informative x 1
  14. How about loctite? I used the liquid stuff so the thread was wet with this stuff before it screwed in. It was anaerobic loctite so it only reacts to the metal, not the air and it was only exposed to the air for no more than 30 seconds anyway.
  15. Is it possible to use a cordless drill to drill the pilot hole?
    Got, I think, a 12v cordless one.
  16. This is a great thread.

    I had my own issue's with a broken sump plug recently. I just think back to what the Chairman or Brucey would do :LOL: . I think a trick is to take a moment and have a little think about the problem. Cordless drills are also handy for drilling out the required bolt, but the most important item is sharpened drill bits and a little bit of penetrating oil soaked into the thread. I have an 18 V one with varying speed and torque settings.

    The next thing I am going to invest in is a full set of screw extractors (easy outs) plus a matching set of reversed drill bit to match.

    Could some one also please clarify the need for grease on bolts that require loctite?

    An example is I put loctite on my brake caliper bolts (Haynes manual suggests this), but I tend to grease or lube all other bolts that require a decent torque setting (say over 15 Nm).

    Should I grease the loctited bolts or not?

    Top work everybody, and I will buy beers for all.
  17. Yeah, that should be ok. My motor guy recommends putting "it" (lube) under the head of the bolts too, so when they make contact with the surface there's no metal-on-metal friction. Loctite might be a bit messy in that application.

  18. The underside of the bolt head requires grip to allow the bolt to function correctly. This friction holds the bolt in place as well as applies the clamping force to the fastened object/s. Lubricating this part of the bolt can contribute to it coming loose. Lubricate the threads only.
  19. No -you should NOT grease or lubricate the threads when they are going to have Loctite applied. The Loctite itself will provide plenty of lubrication for the correct torque to be applied. Loctite are specific in advising that the threads be cleaned of all oil & grease. Even sell cleaning products for the exact purpose :)
  20. I broke an easy out :(

    The name is deceptive, it didn't come out easily at all.

    I wonder where is the place to go to get a helicoil done, sydney, central coast, newcastle?