weld vs bolts

[tarsho1991]

Okay I know that this does not have anything to do with hot rods street rods or even cars but I have to find a biased group to ask. I do alot of off roading with a full size Bronco, it weighs around 5000 lbs (approx.) and I need to attach tow points to it, for club participation. I have a set of "D" rings that are rated for 15000 lbs. The clubs rules say that the tow points need to be at least rated at 1 1/2 times the weight of the vehicle, so my "D" rings are definatly going to work. Now the question, Should I weld the brackets on or bolt them on?? Different ppl say different things. I know that the weld will break before the it bends and that a bolt grade 5 or 8 will bend before they break, and that is a major point that alot of the other ppl have said to make the bolts better than weld. My thoughts are that when you build a roll cage, you weld it together, and they can stand a tremendous impact without breaking. I have been part of a pit crew for a local track before and have seen the roll cage bend before the weld breaks (which I know is supposed to happen) but if a person thinks of it, a Dirt track car weighs around 2300 lbs (??) and going at 90 mph and blows a tire and drives the car into a wall, you don't see welds break. So if I do weld on the attachment points am I asking for trouble?? should I go with the others ideas and just bolt them on?? I have to think that when my 5000lbs bronco is stuck in the mud that the mud will act like a vaccuum holding it in. or over a rock....... I am at a loss and any ideas would be appreciated.

[lt1s10]

that would come down to with what and who is doing the welding. the weild can be as good as the bolts, if its done right. anything less than a 100% weild id go with the bolts. JMO

[FMXhellraiser]

Mike is right. If you can weld good or know someone that is very good then weld. Thing about welding is yes it will crack or snap but if you have a welder or know someone with one around you just grind it back to normal and nice and weld it on again. Personally I don't like bolts, they come loose and are annoying (I dont know why but they are) and plus I just love welding anyways so that would give me another reason to weld.
my vote is to weld.

[Henry Rifle]

If your D rings are rated at 15,000 lbs, they may be something other than ordinary steel. Welding them may kill the temper - or worse, make them brittle. I would attach them with proper bolts.

[canadianal]

hey tarsho you say you have d rings . do they have a mounting flange or would they bolt directly. some of the d rings i have seen have a kind of heavy d ring with a flange that would bolt or weld to the bottom or side of a frame. 11/2 times the weight of your truck isnt a big pull when it comes to 4x4ing.
you may look at reinforcing the pull point on the frame also.
i have seen in my job ,trucks in the oilfields that got stuck and had a good 4x4 hookup pulled right out of the frame.
i have also seen a truck that got really stuck and they used a 4 wheel drive tractor pull it out. the pull point did not pull out on that one but the front of the truck was over 8 inches longer on onside compared to the other. what a mess.

[Henry Rifle]

Denny,

Any lifting/pulling device has to have a safety factor - usually 3:1 or greater. Factors of 7 to 10 are not unusual.

I'm guessing that a D-ring rated at 15k would go at least 30k, but no one should exceed the rating. Also, I make it a point never to be around a cable under tension.

[Thunderbucket]

Bolt Then Weld,,if you plan on leaving them on.

[tarsho1991]

The D rings do have a flange that the rings stay inside of, and they do not have a point to bolt the flange (I would have to make a flange myself if I were to bolt them.) Also these would be permanent, the front ones would require the bumper to be cut out around the frame and the flanges would be attatched to the front of the frame(bumper mounts to the side of the frame) and the rear ones would be attached to the reese hitch, and become permanent also. The idea is to keep the Bronco safe enough for the road but use it mainly for an off roader or tow vehicle for the car trailer. thanks for the opinions.

[autocityman4]

yeah what he said

[Dan J]

OK, so I’m really late getting in on this discussion... I guess that’s what happens when you don’t check in but once every couple of weeks.

The short answer (many other factors are involved) is that a welded connection’s strength is determined by weld length times thickness of weld, and a bolted connection’s strength is a factor of bolt diameter. Again, there are many other factors involved but these are the basic factors.

First, how large is the D ring bracket? The length of weld you get around the perimeter of the bracket will determine how strong the connection. Also, if you use large high strength bolts you’ve got to be careful not to concentrate the stress in a small area or you’ll pull the bolt through the frame rail

I’d check with the D ring manufacturer for some “engineered” recommended connection details.

Dan J