What's the strength of the nut on a mild steel eye bolt?

[TomBrooklyn]

I have an application where I want to use a 1/2" folded eye bolt to support a load of 300 lbs with a safety factor of 3x.

Without doing any calculations, intuitively I'm sure a 1/2" folded eye bold can easily hold 300 lbs and has an ultimate breaking point somewhere north of 900 lbs. I plan to weld the eye bolt closed for a little added strength to boot.

What I'm not sure of is if the threaded nut can hold the same weight. What about that?

 

[JStephen]

The general idea is that the nuts can handle the strength of the bolt. But for this work, you need to follow the specifications of the bolt for the proper nut to use. For example, the ASTM A307 bolt standard will tell you what nuts should be paired with A307 bolts, although the nuts aren't included in that standard.

 

[jetmaker]

I'd be careful with welding the eye shut, as the welding operation may have an adverse effect on the overall strength as this is likely the critical region.

jetmaker

 

[TomBrooklyn]

Hi,
Thanks for the comments. The notifications of the replies went into my spam folder so I just found them.

After I posted I found a little sticker on the bolt (which I had bought some time earlier at Home Depot I think, that indicated the working load was 300#. So that's fine. I don't know what the difference in ultimate strength and working load is, but I assume it's a healthy multiple.

I'm pretty sure this is a common mild steal eye. What would that be, Grade 3?

So I'm thinking any nut would be of that minimum grade.

How does it go? Generally speaking, any nut of the same grade as the bolt it goes on is designed to be stronger than the bolt?

 

[dimjim]

You are right. The nuts are designed so that the
bolts fail first.

 

[desertfox]

Hi TomBrooklyn

As Dimjim states and JStephen standard nuts of the same material grade as the bolts are designed to handle the bolt loads and usually if anythings going to fail its the bolt.
Not sure why your going to the trouble of welding the folded eye closed though under that circumstance why not just use a forged eye.
I did a search but couldn't find anything on safe working loads or exactly what grades of material the eyes are made out of just general statements like mild steel, stainless steel etc.
Are you only using one eyebolt ie just a single point lift?

Regards

desertfox

 

[TomBrooklyn]

Hi. Yes, just one eyebolt. I don't know where to get a forged eyebolt.

 

[desertfox]

Hi TomBrooklyn


Try these sites:-

http://www.boltdepot.com/Fastener-Information/Eye-Bolts/Forged-Eye-Bolt-Working-Load-Limits.aspx

http://www.stanleyproto.com/default...LTS&strSiteName=PROTO&strDefaultCatalog=PROTO

http://www.nail-screw.com/x_eye_bolt.htm

I just did a search for forged eyebolts and these were just a part of the first few.

Regards

desertfox

 

[unclesyd]

Just go back to the big Orange Box as the have forged eye bolts. I just bought 3 3x3/8" forged eye bolts Saturday.

 

[csd72]

You will be surprised at how weak those folded eye bolts are if you did the numbers. I would definately use a rated forged eye bolt as has been suggested.