Eye bolts into joists/noggins for hanging chair, gym rings etc

[jugglesm]

Hi all, I hope I'm posting in the right forum.  I've previously installed 10mm pigs' tail coach screws into joists above the living room to allow my kids to install gymnastics hang bar, gym rings etc.  They always seemed a little undersized to me and we are currently having an extension built so I'd like to find something a little more robust.  There is plenty of steel in the ceiling but the builder thinks it would be simpler and cheaper to go direct into wood or noggins.

 

Would something like this fit the bill? https://www.gsproducts.co.uk/12x120mm-stainless-steel-wood-screw-lag-thread-eye-bolts/?gad_source=1&gclid=CjwKCAiAnKi8BhB0EiwA58DA4SvrehqGzBiX2TPYUsIkmvemADj85wqrwjobGKr0DVPDyM2cGcwdyxoCJkYQAvD_BwE

 

Or is there another option I should be considering?

 

Thanks in advance for any help

[Redbeard]

While trying to find something cheaper for you (insofar as I suspect mild steel will be fine, BZP would be arguably finer, 'prper' galvanised all you need and SS OTT) I found this, which caused me amusement. It may to others. I wonder about the tensile strength: "Marine Eye Bolt Stainless steel with Wooden Thread"

[Redbeard]

From 2-wheel days I also remember endless arguments in Motorcycle Sport magazine re the correct grade of stainless for this, that and the other use. Not all opinions are the same!

[jugglesm]

Thanks Redbeard, I think the one's I've used previously are galved and they have started to flake/corrode where I have clipped carabiners to them.  That's why I was looking at stainless steel.  Worthwhile do you think?

[Redbeard]

OK, yes, I was thinking rope rather than carabiners. Metal-metal contact and swinging might erode the galvanising, but is it going to corrode, in your living room? How moist is your living room?! Likely answer: Not moist enough to promote rust/future weakness, therefore (as before) do we need SS?

[jugglesm]

... thanks, but ss would work? and they are not prohibitively expensive!

[lookseehear]

I've done something similar in the kids playroom and screwed 3x2 to the ceiling joists running perpendicular, then some little stainless brackets with 4 screws on each into the 3x2s.

 

The stainless ones you linked look like they would be absolutely fine as long as the correct size hole is drilled.

[Redbeard]

31 minutes ago, jugglesm said:

... thanks, but ss would work? and they are not prohibitively expensive!

 

Yes. I imagine the stresses for gym equipment may be less than for some motorcycle applications, but I would guess you still have to be careful. I would tell the supplier the likely maximum loads involved (+ a bit!) and get them to tell me which ones I need, rather than just choosing one out of a catalogue or off a display.

[Alan Ambrose]

Nice idea for kids .

 

Hmmm, bolts in shear, preferably into steels? Yes, SS if you like, they are used in high load marine environments. If no calculations are done, you could always load, say, 3-5x the kids weight onto them (you and the missus?) and then dynamically load (jump?) to check they're sound.

[jugglesm]

thanks all, @Alan Ambrose  the plan is to install directly into wood as this gives us more flexibility over where to locate them vs the steels.  I have just spoken to GS products, who say (quite reasonably) that they don't give any working load limit for bolts with wood threads as the strength is dependant on the quality and type of wood.  That being said I feel that a higher diameter wood thread (12mm vs the 10mm I used before) should give a stronger fixing.  

[lookseehear]

40 minutes ago, Alan Ambrose said:

Nice idea for kids .

 

Hmmm, bolts in shear, preferably into steels? Yes, SS if you like, they are used in high load marine environments. If no calculations are done, you could always load, say, 3-5x the kids weight onto them (you and the missus?) and then dynamically load (jump?) to check they're sound.

 

This is what I always do. Have a good jump on it myself and know that the kids at 1/4 of that will be no problem.

[Redbeard]

Or get proper eye bolts (not eye-screws) with a long enough shank to go through the joist and bolt them through, with big washers.

 

Edit: Grrr. Forgot the quote, and can't delete this despite pressing 'cancel'!

Edited 14 hours ago by Redbeard

[Redbeard]

8 minutes ago, jugglesm said:

I have just spoken to GS products, who say (quite reasonably) that they don't give any working load limit for bolts with wood threads as the strength is dependant on the quality and type of wood.  That being said I feel that a higher diameter wood thread (12mm vs the 10mm I used before) should give a stronger fixing.  

 

Or get proper eye bolts (not eye-screws) with a long enough shank to go through the joist and bolt them through, with big washers.

[jugglesm]

thanks redbeard, that might work well if I keep the noggins slightly shy of the joist tops