Grade A threaded rod torque ?

[xtal01]

Hello,

I have looked all over the web for a chart showing the correct torque for nuts on a threaded rod.

Found lots of charts but values all over the place.

The issue might be the material.

The threaded rod is 1/2"-13 hot dip galvanized grade A

So, this is the lowest strength rod available.

I definitely don't want to over torque it.

Galvanized rods seem to have a higher ft lb torque rating.

Can someone tell me the value or point me to a chart with the correct torques for nuts on this rod?

Here is a link to the rod (bought at Zoro) Link

Thanks .... Mike

 

[JStephen]

Generally, the torque would come up when you're trying to achieve some particular amount of tension in the assembly. Without any target value of tension, I don't see why you'd specify a particular torque.

 

[xtal01]

Long story but we are using these to hold down a shed to a pad (watched a neighbors fly away in a wind gust).

Very small shed ... just didn't want the wind to take it.

We epoxied a bunch of these into the concrete pad.

I was just afraid of breaking or stripping them.

Just looking for a value to set my torque wrench to.

mike

 

[XR250]

I doubt you will find an answer. Why not just use locknuts or lock washers? Torquing them will not make them any stronger.

 

[Once20036]

Have you checked with the manufacturer of the epoxy you used?

 

[xtal01]

Thanks!

Just tried 5 ... they all held.

I realized that it might be pointless finding a value ... I am using a Harbor Freight torque wrench .. probably off by 100%

I set a 3/8 drive to 25 ft lbs .... I think I am double that. The washer pulled into the 2 x 6 before it "clicked".

I am using lock washers and large washers.

I am sure it will be fine for what I am doing.

I used AC100+ Gold

I followed the instructions including blowing out and mechanically brushing the hole.

Must have done something right ... the first 5 held.

Thanks again!

Mike

 

[dvd]

In particular, torquing against wood is a losing battle - the wood grain will crush and compress over time and tension (created by the elusive torque) in rod is lost. Use loctite, locknuts, etc.

 

[xtal01]

I am realizing exactly that.

Went back tonight and checked the torque ... almost every one needed a bit more to tighten.

I can just imagine over time as the wood dries and shrinks what will happen.

Makes me wonder why they use this method to hold down a house.

Mike

 

[oldrunner]

Review a some of Simpson's strong tie anchor bolts for a size of a plate to use under the nut. I think that they have some recommendations for tightening. Review ACI 318 for their recommendations. What have you considered would fail first? The bolt or the concrete?

 

[BridgeSmith]

The nuts don't need to be torqued down in order to keep the shed from blowing away in the wind. They just need to be snugged down so that they're against the bottom plate. If you're concerned about the nuts loosening up, you can use a threadlocker, or if you want to be able to snug them up later, after the wood dries and shrinks, use nyloc nuts.

Rod Smith, P.E., The artist formerly known as HotRod10

 

[dvd]

Simpson holdown info - illustrates some aspects to consider

 

[xtal01]

Awesome guys!

Thanks for the link.

This is probably over kill for a small shed but I figure better safe then sorry.

Thanks so much again !

Mike