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Discussion Starter · #1 ·
I was at my sister-in-laws trying to mount her 50in samsung plasma with this bracket http://www.monoprice.com/products/pr...seq=1&format=2 , I decided to go on the wall instead of the fireplace but when I ran the bolts into the studs using my Milwaukee magnum electric drill the bolts kept snapping as I ran them down. any advice?
 

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First, loosen the clutch on your drill. You've got it set too high.


Second, pre-drill holes with a bit that's slightly smaller than the shaft of the bolts you're using (but only slightly).


Third, pre-lubricate your bolts by packing the threads with scrapings from common household bar soap. Or, if you prefer, you can use paraffin (available in most people's home in the form of votive or table candles). (This is an old woodworkers trick that my grandfather taught me more than forty years ago. Thanks Grampa.)


Casey
 

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Discussion Starter · #3 ·

Quote:
Originally Posted by leedom /forum/post/15521764


First, loosen the clutch on your drill. You've got it set too high.


Second, pre-drill holes with a bit that's slightly smaller than the shaft of the bolts you're using (but only slightly).


Third, pre-lubricate your bolts by packing the threads with scrapings from common household bar soap. Or, if you prefer, you can use paraffin (available in most people's home in the form of votive or table candles). (This is an old woodworkers trick that my grandfather taught me more than forty years ago. Thanks Grampa.)


Casey

thanks, i will give it a shot, using new holes since the end of the bolts are in the others
 

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Quote:
Originally Posted by kiddk1 /forum/post/15521842


thanks, i will give it a shot, using new holes since the end of the bolts are in the others

You can remove those if you want -- though it'll almost certainly require a trip to the hardware store for a new tool! :)


What you do is drill a small hole down the center of the bolt that's broken off (very hard) and then use a cool little bit which has reverse expanding grooves. You push this bit into the hole you've drilled in the broken bolts and start turning backwards. The reversed expanding grooves bite into the edges of your hole and allow you to extract the broken bold. There's a specific name for this tool but I've forgotten what it is.


The other option involves making a larger hole in the wall around the broken off bolt in order to expose enough of the end so you can get a grip on it with vice grips, etc. you extract. This is the brute force method.


Of course, if the broken end of the bolt won't show, you can just leave it there.


Casey
 

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Discussion Starter · #6 ·

Quote:
Originally Posted by leedom /forum/post/15522540


You can remove those if you want -- though it'll almost certainly require a trip to the hardware store for a new tool! :)


What you do is drill a small hole down the center of the bolt that's broken off (very hard) and then use a cool little bit which has reverse expanding grooves. You push this bit into the hole you've drilled in the broken bolts and start turning backwards. The reversed expanding grooves bite into the edges of your hole and allow you to extract the broken bold. There's a specific name for this tool but I've forgotten what it is.


The other option involves making a larger hole in the wall around the broken off bolt in order to expose enough of the end so you can get a grip on it with vice grips, etc. you extract. This is the brute force method.


Of course, if the broken end of the bolt won't show, you can just leave it there.


Casey

Yeah I gave that some thought, I have a set of screw extractors but I think it would be a waste of effort, I will just drill the new holes 3 inches below the others and patch up the old holes.

Quote:
Originally Posted by jaly /forum/post/15523244


It may be worthwhile to upgrade to a heavier duty bolt as well. For a normal US Bolt look at the head (except stainless). No radial lines = grade 2, three radial lines = grade 5, six radial lines = grade 8. Grade 8 are probably overkill, except we are talking a plasma....

http://www.boltdepot.com/fastener-in...ade-Chart.aspx

the current bolts that came wit the mount are grade 2 (thanks for the link I would have never known) I think I will purchase new grade 8 just to be on the safe side.


One more thing, tv along with the mount are really heavy, the manual said something about using straps with heavy duty wire as a precaution in case the mount breaks free from the wall, is this overkill, I am just a little concerned that I should use some kind of safety in case of this?
 

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Try using a manual wrench like I'm sure it says in the manual and you sure can't finish them off with the drill like that they'll snap use some hand tools and take 2 seconds longer.
 

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Quote:
Originally Posted by kiddk1 /forum/post/15521548


......when I ran the bolts into the studs using my Milwaukee magnum electric drill the bolts kept snapping as I ran them down. any advice?

Did you drill a pilot hole first? If so, what size drill did you use?


What size are the bolts that broke?


It's imperative to drill a pilot hole of the correct size for the size of the bolt. Not doing this correctly not only can break the bolt, some of the other bolts that appear to have survived could actually have hidden fractures and when you hang the heavy TV on the bracket the bolt breaks under the sudden added weight. And failure to drill proper pilot holes can also cause the bolts to split the wood stud and that can result in the TV pulling the mount out of the wall.


Here's some good information about installing Lag Bolts:
http://www.mcfeelys.com/category.asp...olts|939219301
 

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Discussion Starter · #9 ·
thanks for that link, looking at it my pilot hole was definitely not as large as it should have been, I will use the chart as a guide after I purchase new bolts.
 

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Quote:
Originally Posted by kiddk1 /forum/post/15523437


Yeah I gave that some thought, I have a set of screw extractors but I think it would be a waste of effort, I will just drill the new holes 3 inches below the others and patch up the old holes.

Yeah, probably not worth it. Mostly I was thinking in terms of if you ever move and want to leave the place in good shape.

Quote:
the current bolts that came wit the mount are grade 2 (thanks for the link I would have never known) I think I will purchase new grade 8 just to be on the safe side.


One more thing, tv along with the mount are really heavy, the manual said something about using straps with heavy duty wire as a precaution in case the mount breaks free from the wall, is this overkill, I am just a little concerned that I should use some kind of safety in case of this?

Properly installed with good quality bolts, mount, etc. it should be virtually impossible for a heavy TV/mount to come out of the wall. Most of the force is straight down so you'd have to shear through all of the bolts. Even cheap bolts should be able to handle that but the bolts you have sound like Really Cheap bolts. I think you'd do well to spend the few dollars for better bolts/washers.


Also, setting you clutch fairly loose so the drill can't over-torque the bolts really is important. As someone else said, finish them off with a manual socket set and then you will feel how much force you're using. After all, the only real goal is to get the bolts snug -- i.e. the mount doesn't jiggle around the bolts. There's no extra strength imparted by tightening them further since this is a static load.


Casey
 

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Discussion Starter · #11 ·
thanks for all the advice, I couldnt have done this without the advice given
 

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If you're snapping the heads off of the bolts, you don't need a higher-grade lagscrew -- you need a pilot drill slightly smaller (1/8") than bolt's thread width. To be thorough, it wouldn't hurt to run a second drill, the same size as the unthreaded shank near the head, and run it as deep as the unthreaded portion of the lag screw runs.


If you just blindly go to a stronger grade of bolt, what you'll end up with is a compromised, fractured stud you won't be able to see.


Apart from "grade" of bolts, some of the cheaper Chinese lagscrews have inferior zinc plating which can make them even weaker than a Grade 2 normally is. In your case, count your blessings -- probably saved you from a split stud. Non-plated lag screws may be the best here.
 

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Discussion Starter · #13 ·

Quote:
Originally Posted by PrimeTime /forum/post/15529786


If you're snapping the heads off of the bolts, you don't need a higher-grade lagscrew -- you need a pilot drill slightly smaller (1/8") than bolt's thread width. To be thorough, it wouldn't hurt to run a second drill, the same size as the unthreaded shank near the head, and run it as deep as the unthreaded portion of the lag screw runs.


If you just blindly go to a stronger grade of bolt, what you'll end up with is a compromised, fractured stud you won't be able to see.


Apart from "grade" of bolts, some of the cheaper Chinese lagscrews have inferior zinc plating which can make them even weaker than a Grade 2 normally is. In your case, count your blessings -- probably saved you from a split stud. Non-plated lag screws may be the best here.

thanks, but did you see my post (3 up), I believe I said my pilot hole was not large enough, that was probably the main issue. Jaly also stated a stronger bolt (grade 8) may be overkill but I believe better safe than sorry.
 
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