Unthreaded Carriage Bolt Blanks?

[lastcowboy32]

We picked up a used NH 155 elevator. The windless cables were a little off kilter. They were new, but strung incorrectly. We got a deal at TSC for two cable remnants that were just the right length at TSC, and replaced them.

In the process, I removed the cast idler wheels at the top that the cables go around. They are both mounted with 1/2" x 3-1/2" (estimated) carriage bolts. Both bolts are worn quite a bit. I've been in situations like this before, where I need a carriage bolt that serves as a shaft for a roller or wheel. But, when I buy them, they are often fully threaded, which means that they wear out prematurely. This is true even when I go to the local dealer and ID the bolt in the part diagram. They just grab a carriage bolt from the bin.

It would be nice to get blanks that I could thread only on the ends.

Is this a thing?

 

[Mike(NEOhio)]

Bolt threads are usually rolled not cut with a die. The area to be threaded is undersize and rolling increases the diameter. Even if you could find
some blanks there's likely not enough diameter to cut threads deep enough to work.

 

[flying belgian]

Buy some 5 inch and cut the threads off.
Then cut some new threads.

 

[BarnyardEngineering]

(quoted from post at 05:52:34 07/17/23) Buy some 5 inch and cut the threads off.
Then cut some new threads.

Even the 5" ones are fully threaded. McMaster Carr has some partially threaded, but they still have 6" of threads on them. You'd have to go to a 9" bolt to get one with 3" of clear shank.

Plus as Mike said there won't be enough meat there to get a decent thread.

If there's room for the head, just use a standard bolt. In most cases it doesn't HAVE to be a carriage bolt.

 

[DanielW]

Carriage bolts are a little more varied in what standards they conform to - sometimes they're fully threaded (even
up to 8 long), sometimes they conform to the more typical standard (thread length = 2X Bolt Diameter + 1/4'').
Exactly what you get seems to depend on where they were made: If imported from overseas, they're typically fully
threaded no matter what grade. If made in North America (harder to find), they conform to the above standard. Look
at the link below under where it says, 'thread length'.

Where we order them from (Spaenaur), grade two are imported and fully threaded, while Grade 5 or higher are made in
Canada and partially threaded as per the above rule, so if you bought a Grade 5 at 5'' long you'd have 3 3/4 of
unthreaded shank you could run a die down.

Others have made a good point about the shank diameter being a little undersize. I don't think I'd worry about that
for an idler sheave, however: running a die down will still give enough threads that a nut will catch. If you're
worried about it, thread a little longer and put two nuts on there. If it was something like wheel axle where it
would see side loads when turning I'd definitely be worried about it, but for your cable sheave idler that nut will
hardly take any load.

Or you could do as suggested and just use a regular bolt, which will be easier to find with an unthreaded shank -
assuming you can get to the head to put a wrench on it.
Carriage Bolt Thread Length Dimensions

 

[ss55]

A shoulder bolt with a self-locking nut or two jam nuts would probably do the job better than a carriage bolt. The main body of a shoulder bolt is is hardened.

McMaster-Carr.com ships and takes credit cards.

https://www.mcmaster.com/products/screws/alloy-steel-shoulder-screws-9/

 

[lastcowboy32]

(quoted from post at 06:32:04 07/17/23)

(quoted from post at 05:52:34 07/17/23) Buy some 5 inch and cut the threads off.
Then cut some new threads.

Even the 5" ones are fully threaded. McMaster Carr has some partially threaded, but they still have 6" of threads on them. You'd have to go to a 9" bolt to get one with 3" of clear shank.

Plus as Mike said there won't be enough meat there to get a decent thread.

If there's room for the head, just use a standard bolt. In most cases it doesn't HAVE to be a carriage bolt.

It doesn't "have" to be a carriage bolt, as far as getting at the head goes... but I think that it is, in order to make sure that the bolt stays still when the sheave turns. That way, the bolt doesn't wallow out its mounting holes through friction.

I'm finding out what some of the other comments are saying... carriage bolts of any length with unthreaded sections are hard to find.

This isn't "a hill that I want to die on". In the end, I think that, if I can't get the unthreaded section that I want; I'll just get threaded carriage bolts, load them with a bunch of grease, and run with it. Knowing that I should replace them maybe every few years or so. Replacing carriage bolts is easy. Replacing the bar with the mounting holes is not so easy.

Right now, I have scaffolding erected at the end of the elevator with a 4 x 6 oak timber plank across the top... so I can lower the end of the elevator down and take the pressure off of it. Worked great for replacing the windless cables. I put the old carriage bolts back in, but I can pop them out in a couple of minutes any time this week, while I have the scaffolding there.

The scaffolding also allows me to access the chains, bearings and sheaves at that end of the elevator; which also need a little TLC.

Hoping to have bales running up it in about a week!

 

[lastcowboy32]

Just some pictures of the setup.

We think that the cables broke sometime in the past. It has new cables, but the were routed weird, crossing at the rollers.

We bought new cables of the correct length and routed them correctly, after I went to my brother's farm to check out his NH155, that we had used since we were kids.

 

[lastcowboy32]

I guess photos will have to wait until I get better service...

 

[DanielW]

You're definitely going to get a shorter
life with a threaded shank, and not do the
bearing/bushing in the sheave any favours
either. What about taking a regular bolt
with an unthreaded shank and putting a
small blob of weld right beneath the head.
Then just take the grinder to it so make
some approximation of a square shoulder.
Doesn't have to be perfect, as long as it
sits in the square hole and prevents it
from turning. That way you could also use a
higher grade bolt.

 

[Jim.ME]

(quoted from post at 11:38:50 07/17/23)
I guess photos will have to wait until I get better service...

It appears partially threaded 1/2-13 carriage bolts are available through Grainger. Other places show up in a web search as well.

 

[lastcowboy32]

I would rather not try to weld on a bolt, if I could avoid it. I have visions of creating a stress concentration right under the head.

Ordering from Grainger, if that works, wouldn't be a bad solution.

Thanks!

 

[JoeM(GA)]

I needed some 3 1/2 x 1/2 carriage bolts with 3 of un-threaded shank, ended up having to buy some 10 bolts to get that much blank shaft

 

[DoubleO7]

(quoted from post at 09:13:08 07/17/23) Bolt threads are usually rolled not cut with a die. The area to be threaded is undersize and rolling increases the diameter. Even if you could find
some blanks there's likely not enough diameter to cut threads deep enough to work.

I have used a LOT of bolts that the threads would pass thru a drilled hole but bind up at the unthreaded area.
The same thing with flat washers.

Maybe they were grade 8 or SHCS or some such.


McMaster-Carr is showing 1/2x4-1/2 SS carriage bolts with only 1 inch of thread minimum.
But not how close to minimum.

https://www.mcmaster.com/92356a730/

This post was edited by DoubleO7 on 07/17/2023 at 06:43 pm.

 

[caterpillar guy]

Just use a regular bolt and tack the head so it doesn't turn if it is that big of a problem. I doubt if they are kept greased that they will turn that much. I believe NI used to just put pins with cotter pins through them for the cable pulleys. I think one of our augers is even that way. I suppose I should check them one of these days. Will probably be like everyone else and not until there is a problem.