# Probably dumb question about carriage bolts



## Larryh86GT (Feb 2, 2013)

I've used them without a washer at the head end and just sucked the square portion into the wood and put the washer at the nut end.


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## joecaption (Nov 30, 2011)

No washer needed.
The whole idea or the square part is to hold the bolt in place so you can tighten up the nut without the bolt turning.


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## woodworkbykirk (Sep 25, 2011)

what joe said.. if the carriage bolt is exposed not having the washer gives a cleaner look.. you need the washer on the opposite end though where the nut is


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## Daniel Holzman (Mar 10, 2009)

Carriage bolts can be a PITA on for deck applications. If the square head is driven into the wood, and the wood dries out (which is common with PT lumber), the square head may no longer be tight enough to prevent rotation of the carriage head when you tighten the nut. It is very common for bolts to loosen up after one season or so since PT lumber is often quite green when first purchased, and as it dries and shrinks, bolts can become loose, and it may difficult to tighten carriage bolts adequately. I recommend use of standard hex head bolts, they can always be tightened.


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## tony.g (Apr 15, 2012)

Why are they called carriage bolts in the first place?


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## joecaption (Nov 30, 2011)

http://www.blacksmithbolt.com/gpage14.html

Dan where are you going to find hot dipped hex bolts.
The nuts only need to be snug to do there job.
There mostly for shear loads.


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## jagans (Oct 21, 2012)

They are called carriage bolts because the frame of carriages were punched with square holes to hold the square portion under the head so you dont need a wrench on one end. You can still find square holes punched in the frames of automobiles today for the same purpose.

The multiple problems with using them on wood are for one thing the fact that the square portion reams out the wood which has very little resistance to torque. The cross section of wood is resting on threads which can cut into the wood fiber. Last and worst: You cannot put a washer on the head end to distribute the load over a larger area, like a split ring connector does.

Incredibly, and due to their infinite wisdom, some barney fife local building codes actually require them.

*"Forgive them father for they know not what they do"* Comes to mind.


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## nikeman (Nov 8, 2010)

Thanks guys. I'll stick with carriage bolts. If they get lose I know I can get them snug again. I got stainless carriage bolts because they do look a lot better than the galvanized bolts and they will be visible all the time. I figure the large round head will act like a washer anyway.


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## A Squared (Dec 19, 2005)

jagans said:


> The cross section of wood is resting on threads which can cut into the wood fiber.


Well, no. Again, carriage bolts do not necessarily have full length threads, many have shanks. Didn't we just have this conversation a few days ago? 


this is a carriage bolt:











these are carriage bolts:










these are carriage bolts:










Like I said in the previous thread, what makes a carriage bolt a carriage bolt is the style of head, not whether or not it has a shank.


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## nikeman (Nov 8, 2010)

I made sure to get bolts with a long threaded area over the ones that were only threaded for the last inch or.


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## Daniel Holzman (Mar 10, 2009)

You can get hot dipped galvanized or stainless steel bolts, washers and nuts at any decent hardware store, and most big box stores. Ditto for carriage bolts. For me, it is mostly a preference thing, as I said I don't like the issues with tightening carriage bolts.


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## A Squared (Dec 19, 2005)

nikeman said:


> I made sure to get bolts with a long threaded area over the ones that were only threaded for the last inch or.


well in your particular case, jagen's comment is valid then. It's much better to use a bolt with a shank of the proper size for the material fastened then it is to use one with the material bearing on threads.

I'm just saying that jagen is incorrect when he says that carriage bolts don't have shanks.


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## jagans (Oct 21, 2012)

They are called carriage bolts because the frame of carriages were punched with square holes to hold the square portion under the head so you dont need a wrench on one end. You can still find square holes punched in the frames of automobiles today for the same purpose.

The multiple problems with using them on wood are for one thing the fact that the square portion reams out the wood which has very little resistance to torque. The cross section of wood is resting on threads which can cut into the wood fiber. Last and worst: You cannot put a washer on the head end to distribute the load over a larger area, like a split ring connector does.

Incredibly, and due to their infinite wisdom, some barney fife local building codes actually require them.

*"Forgive them father for they know not what they do"* Comes to mind.


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## stadry (Jun 20, 2009)

lag bolts need wshrs - carriage bolts don't,,, something about carriage bldrs trying to keep a more presentable appearance of their work back in the day,,, ' carriage ' bolts are named for just that purpose,,, imagine that - who'd have thunk it ? ? ? ? :whistling2:


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## jklingel (Dec 21, 2008)

I hate carriage bolts w/ a passion. They are as useless as boobs on a bull shortly after you install them. I would suggest you get a spud bit and countersink hex or slotted-head bolts, hex being my preference. If you don't want to look at the debris that will collect in the countersink, get wooden plugs to fill them in.


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## nikeman (Nov 8, 2010)

As of now I have 4 screws holding the 2 2x12s to the 6x6. I will keep them there with the carriage bolts. I didn't have shorter bolts for that part yet so right now it's only screws.


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## hand drive (Apr 21, 2012)

if it is on your house you will know to check them every few years, the problem is when builders use them on someones home and they loosen after some time has passed.


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## nikeman (Nov 8, 2010)

Also, if it becomes an issue in the future can't I just use locknuts/washers? Worst case scenario ill have to replace them with hex bolts in a few years. Not a hard task so big deal.


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