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Threaded rods vs headed bolts difference
2

Threaded rods vs headed bolts difference

Threaded rods vs headed bolts difference

(OP)
I recently encountered a girth gear in an old ball mill with fasteners (to hold the sections of the girth gear) with threaded rods and nuts on both sides. I do not believe this to be the original design. And it got me thinking about the difference of fastening the gear sections with a threaded rod vs a headed bolt.

I did a bit of research but other than the rod having a lesser tensile strength (with the same diameter), it does not seem to be a difference.

I believe is easier for the rod to get loosen with a rod with nuts on both sides.


What do you think?

JM

RE: Threaded rods vs headed bolts difference

Often a threaded-rod is preferred for no other reason than that using a conventional bolt would have been impractical due to the length required.

John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without

RE: Threaded rods vs headed bolts difference

But you need to look at the hole also.
Was this designed for a smooth shank to help carry load or hold alignment?
Often threaded rod is crap for tolerances and strength.
The original design may be studs with threads on both ends, it would pay to find out.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

RE: Threaded rods vs headed bolts difference

I assume there was some portion of the shank unthreaded and with flats ?
and that the joint (ie the pieces being held by this) couldn't be clamped up, but could be controlled to a precise (ish) gap.

another day in paradise, or is paradise one day closer ?

RE: Threaded rods vs headed bolts difference

For anchor rods, I always spec threads to be cut on both ends to accept a heavy hex head nut... easier to obtain the mat'l and grade.

Dik

RE: Threaded rods vs headed bolts difference

Are you sure that threaded rod is manufactured by cutting the threads? I ask because of this:

https://www.youtube.com/watch?v=dpt6RRiUccM

John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without

RE: Threaded rods vs headed bolts difference

(OP)
To EdStainless,

Sometimes these type of gears have 2 bolts for tightening (on each side, 4 total) and 2 to be used as guides (4 total), with a smaller diameter. In this case is an old mill, so who knows originally what was the case. But the 4 rods (on each side, 8 total) are the same diameter.

JM

RE: Threaded rods vs headed bolts difference

are these rods quite long ? what is the longest bolt you can get commercially ?

another day in paradise, or is paradise one day closer ?

RE: Threaded rods vs headed bolts difference

(OP)
The rod is quite long 13”, however, the length is in part because there is a need to place a nut, washer and a jamnut. When a headed bolt is placed, I’ll only need 10” length.



JM

RE: Threaded rods vs headed bolts difference

Greg and John... I cut 1"thread on one end and 4" on the other... I don't usually use threaded rod due to uncertain nature and supply.

For regular strength, I usually us 18x dia and for high strength 24x dia.

Dik

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