Hi all,

Ideally this is aimed at those who have actually used 'Rivet Nuts' in
a professional / commercial environment please ...

I am considering using said to help restore a professional 'take down'
motorcycle recovery trailer where many of the fastenings would be
inside a rectangular steel box section which would make fitting nuts
on the back of machine screws complicated (I'm aware it's possible
with nuts welded to strap or spacer tubes and bolting though etc).

In most cases these fastenings would either be in shear or simply
holding a joint already under compression in place. And example would
be a tie-down 'loop' that would be fastened to either side (front and
back) of the axle tube.

So, I was wondering if these Rivet Nuts could provide a practical
solution (assuming they could replace conventional nuts etc) and if so
does anyone have any practical / personal recommendations re makes or
suppliers please?

I'm probably looking at M8/10 machine screw sizes going into ~3mm
rolled steel box and angle iron, I'd be using steel Rivet Nuts (I'm
not sure stainless Rivet Nuts would be ideal into mild steel?) and
only need 10's, not 100's etc.

Should we use the special tool (again, production speeds aren't an
issue here) or can a simple bolt and back nut and a thrust bearing or
some washers provide the same effect?

Cheers, T i m

In article ,
T i m wrote:
I'm probably looking at M8/10 machine screw sizes going into ~3mm
rolled steel box and angle iron, I'd be using steel Rivet Nuts (I'm
not sure stainless Rivet Nuts would be ideal into mild steel?) and
only need 10's, not 100's etc.

I've used them a lot. Although generally smaller sizes.

Should we use the special tool (again, production speeds aren't an
issue here) or can a simple bolt and back nut and a thrust bearing or
some washers provide the same effect?

A decent tool is IMHO essential for setting them correctly. And make sure
spares are available for it.

I use M3 quite a bit and it is tricky to get exactly the right setting
without snapping off the arbor on such a small size. Needs to be a very
high quality steel used to pull it tight - a normal bolt will likely not
be strong enough. And turning a bolt rather than pulling on it more likely
to damage the thread.

So saying, larger sizes seem easier.

I'd guess a tool which automatically produces the correct 'pull' for any
given size ain't going to be cheap. Most of the lower priced ones rely on
you providing the correct force. Although can be set to a limit. If you
are doing lots into the same material, you could experiment for the best
settings on some offcuts. And keep those settings.

--
*Most people have more than the average number of legs*

Dave Plowman London SW
To e-mail, change noise into sound.

T i m wrote:

Ideally this is aimed at those who have actually used 'Rivet Nuts' in
a professional / commercial environment please ...

Not really, but I used at home to fix a tubular stair handrail

So, I was wondering if these Rivet Nuts could provide a practical
solution (assuming they could replace conventional nuts etc)

I certainly got rock-solid fixing from them

and if so does anyone have any practical / personal recommendations
re makes or suppliers please?
I used A2 stainless grooved rivnuts from About Town Bolts

Should we use the special tool (again, production speeds aren't an
issue here) or can a simple bolt and back nut and a thrust bearing or
some washers provide the same effect?

I got the el-cheapo Silverline tool, which was OK for fitting a dozen
rivnuts, but probably not designed for stainless as it came off slightly
worse for wear.

On Sun, 13 May 2018 12:42:15 +0100, "Dave Plowman (News)"
wrote:

In article ,
T i m wrote:
I'm probably looking at M8/10 machine screw sizes going into ~3mm
rolled steel box and angle iron, I'd be using steel Rivet Nuts (I'm
not sure stainless Rivet Nuts would be ideal into mild steel?) and
only need 10's, not 100's etc.

I've used them a lot. Although generally smaller sizes.

Would you think that in a worst case situation (tension) they would
offer as much strength / pull-though resistance as a conventional hex
nut Dave? I was thinking a nut would offer a greater surface area but
maybe the bolt or it's thread would fail first in any case?

Should we use the special tool (again, production speeds aren't an
issue here) or can a simple bolt and back nut and a thrust bearing or
some washers provide the same effect?

A decent tool is IMHO essential for setting them correctly. And make sure
spares are available for it.

Understood. That may be on my wish list though, depending on the
price.

I use M3 quite a bit and it is tricky to get exactly the right setting
without snapping off the arbor on such a small size.

Understood.

Needs to be a very
high quality steel used to pull it tight - a normal bolt will likely not
be strong enough. And turning a bolt rather than pulling on it more likely
to damage the thread.

Ok.

So saying, larger sizes seem easier.

I think I would use the 'backnut' process where the bolt thread stays
still in the rivet nut and the rivet nut just drawn in without the
thread turning. I might also turn up a 'tool' to ensure they are held
in firmly and square etc.

I'd guess a tool which automatically produces the correct 'pull' for any
given size ain't going to be cheap.

My fear also ... and I'm not sure would be justified in this scenario
and for these quantities.

Most of the lower priced ones rely on
you providing the correct force. Although can be set to a limit. If you
are doing lots into the same material, you could experiment for the best
settings on some offcuts. And keep those settings.

Understood. I have several torque wrenches. ;-)

Given you don't need access to the back (to hold a nut) then I was
thinking I could use more of these than I might with a conventional
nut and bolt, think riveting up a ships hull plate versus fixing an
air vent into place etc. ;-)

Cheers, T i m

On Sun, 13 May 2018 12:57:58 +0100, Andy Burns
wrote:

T i m wrote:

Ideally this is aimed at those who have actually used 'Rivet Nuts' in
a professional / commercial environment please ...

Not really, but I used at home to fix a tubular stair handrail

Ok, but you have used them at least. ;-)

So, I was wondering if these Rivet Nuts could provide a practical
solution (assuming they could replace conventional nuts etc)

I certainly got rock-solid fixing from them

Gdgd.

and if so does anyone have any practical / personal recommendations
re makes or suppliers please?

I used A2 stainless grooved rivnuts from About Town Bolts

Thanks Andy ... looks like these might do it:
https://www.abouttownbolts.co.uk/product/a2-stainless-small-head-open-grooved-rivet-nuts-rivnuts-nutserts-blind-nut/


Should we use the special tool (again, production speeds aren't an
issue here) or can a simple bolt and back nut and a thrust bearing or
some washers provide the same effect?

I got the el-cheapo Silverline tool, which was OK for fitting a dozen
rivnuts, but probably not designed for stainless as it came off slightly
worse for wear.

And only goes up to 8M etc.

I could turn up a tool to allow the nut to be drawn 'square' and as
long as you don't turn the thread in the insert whilst drawing, I
can't see how doing it that way would be much different to using the
tool etc. At the end of the day, even if it wasn't fully seated during
the fitting process, it would be when the fastening was finally made?

I should be able to 'see' (even if I can't actually get to) the
finished nuts and as Dave suggested, I could do some tests on some
matching scrap in any case.

Cheers, T i m

T i m wrote:
On Sun, 13 May 2018 12:42:15 +0100, "Dave Plowman (News)"
wrote:

In article ,
T i m wrote:
I'm probably looking at M8/10 machine screw sizes going into ~3mm
rolled steel box and angle iron, I'd be using steel Rivet Nuts (I'm
not sure stainless Rivet Nuts would be ideal into mild steel?) and
only need 10's, not 100's etc.

I've used them a lot. Although generally smaller sizes.

Would you think that in a worst case situation (tension) they would
offer as much strength / pull-though resistance as a conventional hex
nut Dave? I was thinking a nut would offer a greater surface area but
maybe the bolt or it's thread would fail first in any case?

Should we use the special tool (again, production speeds aren't an
issue here) or can a simple bolt and back nut and a thrust bearing or
some washers provide the same effect?

A decent tool is IMHO essential for setting them correctly. And make sure
spares are available for it.

Understood. That may be on my wish list though, depending on the
price.

I use M3 quite a bit and it is tricky to get exactly the right setting
without snapping off the arbor on such a small size.

Understood.

Needs to be a very
high quality steel used to pull it tight - a normal bolt will likely not
be strong enough. And turning a bolt rather than pulling on it more likely
to damage the thread.

You don't turn the bolt in the riv nut you screw a nut down on a rod
threaded into the riv nut if you do not have professional tools and that
is perfectly satisfactory although time consuming and you can put a
thrust race under the nut if you have one.

Ok.

So saying, larger sizes seem easier.

I think I would use the 'backnut' process where the bolt thread stays
still in the rivet nut and the rivet nut just drawn in without the
thread turning. I might also turn up a 'tool' to ensure they are held
in firmly and square etc.

I'd guess a tool which automatically produces the correct 'pull' for any
given size ain't going to be cheap.

My fear also ... and I'm not sure would be justified in this scenario
and for these quantities.

Most of the lower priced ones rely on
you providing the correct force. Although can be set to a limit. If you
are doing lots into the same material, you could experiment for the best
settings on some offcuts. And keep those settings.

Understood. I have several torque wrenches. ;-)

Given you don't need access to the back (to hold a nut) then I was
thinking I could use more of these than I might with a conventional
nut and bolt, think riveting up a ships hull plate versus fixing an
air vent into place etc. ;-)

Cheers, T i m

In article ,
T i m wrote:
I've used them a lot. Although generally smaller sizes.

Would you think that in a worst case situation (tension) they would
offer as much strength / pull-though resistance as a conventional hex
nut Dave? I was thinking a nut would offer a greater surface area but
maybe the bolt or it's thread would fail first in any case?

I can't see them being anything like as strong as a nut washer and bolt.

On cars where a blind fixing is needed it's usually a nut welded in place
or a cage of some sort to stop it turning.

Think you'll need a structural engineer to do the calcs. ;-)

--
*Never put off until tomorrow what you can avoid altogether *

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
FMurtz wrote:
Needs to be a very
high quality steel used to pull it tight - a normal bolt will likely not
be strong enough. And turning a bolt rather than pulling on it more likely
to damage the thread.

You don't turn the bolt in the riv nut you screw a nut down on a rod
threaded into the riv nut if you do not have professional tools and that
is perfectly satisfactory although time consuming and you can put a
thrust race under the nut if you have one.

Have you actually done this? As I said a size I often use is M3. Just to
provide an easier fixing than fiddling with nuts an bolts - so access to
both sides. And haven't found 3mm screws strong enough to set it. Might
work if you can source high tensile types, though.

Thing is that M3 arbors are pretty expensive. So I'd guess made out of
expensive material.

--
*Why is the word abbreviation so long?

Dave Plowman London SW
To e-mail, change noise into sound.

On Sun, 13 May 2018 14:35:48 +0100, "Dave Plowman (News)"
wrote:

In article ,
T i m wrote:
I've used them a lot. Although generally smaller sizes.

Would you think that in a worst case situation (tension) they would
offer as much strength / pull-though resistance as a conventional hex
nut Dave? I was thinking a nut would offer a greater surface area but
maybe the bolt or it's thread would fail first in any case?

I can't see them being anything like as strong as a nut washer and bolt.

Hmm, ok. ;-(

On cars where a blind fixing is needed it's usually a nut welded in place
or a cage of some sort to stop it turning.

Noted.

Think you'll need a structural engineer to do the calcs. ;-)

You would think the rivet nut companies would state how close they get
to matching a conventional solution in compression (of the rivet nut
head versus the bolt head though the material), tension (possibly the
failure of the bolt itself) and shear (that might be a close run) but
maybe not if it's not that close? ;-(

If the figures don't come close then I still can weld some self
locking weld nuts to some plate and then screw that inside the section
(so the plate doesn't fall off when removing all the main screws, or,
drill right though the box, open up the back hole large enough to take
a thin-walled socket and use a nylock nut and washer though the hole.

I don't think it would weaken the section sufficiently (it's much
bigger than the original) and I could plug the holes with blanking
grommets to resist the weather getting in. It just won't be so easy to
disassemble as with captive nuts. Or I could turn up some through
spacers (to stop it squashing the box section) and use bolts with nuts
and washers on the outside (I could even bond the spacers and washers
in place with some metal epoxy).

Cheers, T i m

On 13/05/2018 12:25, T i m wrote:
Hi all,

Ideally this is aimed at those who have actually used 'Rivet Nuts' in
a professional / commercial environment please ...

Well I have used quite a lot of Rivnuts. Only in a DIY environment, but
I have done a fair bit of professional work involving design and
assessment of various structures and mechanisms, including threaded
components, and especially the lubrication of mechanisms.


I am considering using said to help restore a professional 'take down'
motorcycle recovery trailer where many of the fastenings would be
inside a rectangular steel box section which would make fitting nuts
on the back of machine screws complicated (I'm aware it's possible
with nuts welded to strap or spacer tubes and bolting though etc).

They are ideal for fixings to box sections. The advantage you will have
is that you know the thickness of the metal, so can pick the right
rivnut. I've used them to fix things like tie rings and toggle fasteners
to welded box section structures in my horsebox, where you are often not
sure what the metal thickness is (and sometimes, because of
accessibility, it's not that easy to confirm the thickness after drilling).

In most cases these fastenings would either be in shear or simply
holding a joint already under compression in place. And example would
be a tie-down 'loop' that would be fastened to either side (front and
back) of the axle tube.

Fastenings in pure shear are basically as strong as the bolt from the
design viewpoint. If you can get the design right, friction provides
some extra shear strength. In practice, many fastenings are going to see
a bit of tension as well as shear.

When you use a nut and bolt in tension, the weak link is usually the
bolt, unless you are connecting such thin (or weak) material that the
bolt head or nut and washer can "pull through". With a fully clenched
rivnut, there is not usually as much "meat" as there would be in a
conventional nut (unless it is a thin nut, as sometimes used for sheet
metal shelving, for example). My experience is that rivnuts are usually
not as strong in tension as the bolt they are used with. They have to be
made from relatively weak steel so that they can be deformed into the
final shape when cold. As with a pop rivet, you may be able to get a
stronger fixing by adding a washer at the back side.

So, I was wondering if these Rivet Nuts could provide a practical
solution (assuming they could replace conventional nuts etc) and if so
does anyone have any practical / personal recommendations re makes or
suppliers please?

I've been happy with the ones that I have bought from eBay. IME it is
important to have drills fairly close to the recommended size, and worth
having really good quality drills. One trouble with box section steel is
that it is not particularly "free cutting" (to use the machinists' term)
and is sometimes a bit difficult to drill near the weld.

I'm probably looking at M8/10 machine screw sizes going into ~3mm
rolled steel box and angle iron, I'd be using steel Rivet Nuts (I'm
not sure stainless Rivet Nuts would be ideal into mild steel?) and
only need 10's, not 100's etc.

Should we use the special tool (again, production speeds aren't an
issue here) or can a simple bolt and back nut and a thrust bearing or
some washers provide the same effect?

You may get away with this in your case especially if you make up proper
jigs and spacers. I'm assuming you would use a rolling element thrust
bearing, also high tensile bolts, and an ordinary mild steel back nut?
Worth using a high moly disulphide lubricant on them. The nuts won't
last long.

If you are buying a tool for general purpose use, then forget the
"cheap" pliers type. Something like the Sealey AK3984 (see eBay) doesn't
look too bad (there are more substantial versions). I uspect M8 and M10
will need something more meaty.

I have one a bit like this

https://www.google.co.uk/search?q=ri...vt7vvBC2zkDPM:

which is great for getting into tight spaces.

For most jobs, I use one of these

http://www.memfast.co.uk/shop/vclose...632&prd=129781

and I love it, even though from the theoretical viewpoint it should not
be as good as a "straight pull" type. It actually works by turning a hex
headed bolt inside the threaded portion (so it puts the rivnut in
torsion as well as tension). You do need to use a good moly disulphide
lubricant on the screw to get good results. Mostly I have used 4 to 6 mm.




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Dave Plowman (News) wrote:
In article ,
FMurtz wrote:
Needs to be a very
high quality steel used to pull it tight - a normal bolt will likely not
be strong enough. And turning a bolt rather than pulling on it more likely
to damage the thread.

You don't turn the bolt in the riv nut you screw a nut down on a rod
threaded into the riv nut if you do not have professional tools and that
is perfectly satisfactory although time consuming and you can put a
thrust race under the nut if you have one.

Have you actually done this? As I said a size I often use is M3. Just to
provide an easier fixing than fiddling with nuts an bolts - so access to
both sides. And haven't found 3mm screws strong enough to set it. Might
work if you can source high tensile types, though.

Yes but used high tensile and sometimes stainless threaded rod (can not
remember grade)

Thing is that M3 arbors are pretty expensive. So I'd guess made out of
expensive material.

On Mon, 14 May 2018 17:30:07 +1000, FMurtz
wrote:

snip

Yes but used high tensile and sometimes stainless threaded rod (can not
remember grade)

From my experience, most stainless fasteners seem to be pretty soft,
they certainly hand-saw / file pretty easily.

I found this interesting:

https://www.haguefasteners.co.uk/bol...0-9-12-9-14-9/

and

https://www.haguefasteners.co.uk/bs-...ded-fasteners/

https://en.wikipedia.org/wiki/ASTM_F568M

And then you get into the various levels of friction with the various
finishes on fasteners and therefore the torque v clamping force etc
etc.

Cheers, T i m

On Sun, 13 May 2018 12:25:46 +0100, T i m wrote:

Hi all,

Ideally this is aimed at those who have actually used 'Rivet Nuts' in
a professional / commercial environment please ...

I am considering using said to help restore a professional 'take down'
motorcycle recovery trailer where many of the fastenings would be
inside a rectangular steel box section which would make fitting nuts
on the back of machine screws complicated (I'm aware it's possible
with nuts welded to strap or spacer tubes and bolting though etc).

In most cases these fastenings would either be in shear or simply
holding a joint already under compression in place. And example would
be a tie-down 'loop' that would be fastened to either side (front and
back) of the axle tube.

So, I was wondering if these Rivet Nuts could provide a practical
solution (assuming they could replace conventional nuts etc) and if so
does anyone have any practical / personal recommendations re makes or
suppliers please?

I'm probably looking at M8/10 machine screw sizes going into ~3mm
rolled steel box and angle iron, I'd be using steel Rivet Nuts (I'm
not sure stainless Rivet Nuts would be ideal into mild steel?) and
only need 10's, not 100's etc.

Should we use the special tool (again, production speeds aren't an
issue here) or can a simple bolt and back nut and a thrust bearing or
some washers provide the same effect?

Used these a long time ago to secure amongst other things about 5kg of fire
extingusiher and 10kg of SLA battery to a bracket that was then bolted to
existing fixings in the floorpan and bodywork crossmember of a competition
vehicle.

http://avdel-global.com/en/products/...erts/dkdl.html

I used two fastenings for the extingusiher and four for the battery

It was sufficient to satisfy me and also pass scrutineering for racing. I used
M8 nuts fixed with the proper tool into ERW steel box section about 60mm x 20mm
with 2mm wall thickness.

I also used them for oil cooler and radiator bracketry both into steel and
aluminium

Unlike copies they provide real data on load capabilities

http://avdel-global.com/fileadmin/us...rts/DLS_mm.pdf
http://avdel-global.com/fileadmin/us...rts/DKS_mm.pdf



--

In article ,
FMurtz wrote:
Have you actually done this? As I said a size I often use is M3. Just to
provide an easier fixing than fiddling with nuts an bolts - so access to
both sides. And haven't found 3mm screws strong enough to set it. Might
work if you can source high tensile types, though.

Yes but used high tensile and sometimes stainless threaded rod (can not
remember grade)

Where did you get high tensile threaded rod?

--
*A nest isn't empty until all their stuff is out of the attic

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
The Other Mike wrote:
Used these a long time ago to secure amongst other things about 5kg of
fire extingusiher and 10kg of SLA battery to a bracket that was then
bolted to existing fixings in the floorpan and bodywork crossmember of a
competition vehicle.

No doubt they are fine for lightly stressed applications. The real
question is are they as strong as a decent nut and bolt for more critical
apps - like say where a torque setting is given?

--
*If tennis elbow is painful, imagine suffering with tennis balls *

Dave Plowman London SW
To e-mail, change noise into sound.

On Mon, 14 May 2018 14:16:31 +0100, "Dave Plowman (News)"
wrote:

In article ,
The Other Mike wrote:
Used these a long time ago to secure amongst other things about 5kg of
fire extingusiher and 10kg of SLA battery to a bracket that was then
bolted to existing fixings in the floorpan and bodywork crossmember of a
competition vehicle.

No doubt they are fine for lightly stressed applications. The real
question is are they as strong as a decent nut and bolt for more critical
apps - like say where a torque setting is given.

M8 insert, 5kN per fastener pull out load = approx 500kg - that was nearly the
weight of the entire vehicle

But it all depends on your definition of lightly stressed, the direction of
loads and your factor of safety. The extinguisher fastenings might survive a
200 G event. But there would be feck all vehicle or driver left to
extinguish.
--

On Mon, 14 May 2018 10:21:20 +0100, The Other Mike
wrote:

snip

Used these a long time ago to secure amongst other things about 5kg of fire
extingusiher and 10kg of SLA battery to a bracket that was then bolted to
existing fixings in the floorpan and bodywork crossmember of a competition
vehicle.

http://avdel-global.com/en/products/...erts/dkdl.html

Thanks for that Mike.

I used two fastenings for the extingusiher and four for the battery

It was sufficient to satisfy me and also pass scrutineering for racing. I used
M8 nuts fixed with the proper tool into ERW steel box section about 60mm x 20mm
with 2mm wall thickness.

Ok. Sounds a neat solution.

I also used them for oil cooler and radiator bracketry both into steel and
aluminium

Ok.

Unlike copies they provide real data on load capabilities

http://avdel-global.com/fileadmin/us...rts/DLS_mm.pdf
http://avdel-global.com/fileadmin/us...rts/DKS_mm.pdf

Handy, thanks.

I still haven't decided which way I'm going to go with this trailer
project but I think I'll get some Rivet Nuts in anyway to play with.
;-)

Cheers, T i m

On Sun, 13 May 2018 12:25:46 +0100, T i m wrote:


Should we use the special tool (again, production speeds aren't an
issue here) or can a simple bolt and back nut and a thrust bearing or
some washers provide the same effect?

I recently helped someone doing a lot of rivnut fixings on a frame
assembly . The tool used was from Memfast
http://www.memfast.co.uk/shop/Vcat1.asp?cat=2250003430

Tool was about £150 with a complete set of mandrels but worked very
well including for 10mm steel rivnuts (although 10mm were moderately
hard work).

We started by trying to use a fairly cheap pop rivet type tool but the
results were poor with some of the set nuts rotating. It was
difficult to hold the tool perpendicular to the workpiece while
applying the large force bigger nutserts required to set them. The
Memfast tool produced no failures and was easy to use.

On Sun, 13 May 2018 12:25:46 +0100, T i m wrote:

Hi all,

Ideally this is aimed at those who have actually used 'Rivet Nuts' in a
professional / commercial environment please ...

I am considering using said to help restore a professional 'take down'
motorcycle recovery trailer where many of the fastenings would be inside
a rectangular steel box section which would make fitting nuts on the
back of machine screws complicated (I'm aware it's possible with nuts
welded to strap or spacer tubes and bolting though etc).

In most cases these fastenings would either be in shear or simply
holding a joint already under compression in place. And example would be
a tie-down 'loop' that would be fastened to either side (front and back)
of the axle tube.

So, I was wondering if these Rivet Nuts could provide a practical
solution (assuming they could replace conventional nuts etc) and if so
does anyone have any practical / personal recommendations re makes or
suppliers please?

I'm probably looking at M8/10 machine screw sizes going into ~3mm rolled
steel box and angle iron, I'd be using steel Rivet Nuts (I'm not sure
stainless Rivet Nuts would be ideal into mild steel?) and only need
10's, not 100's etc.

Should we use the special tool (again, production speeds aren't an issue
here) or can a simple bolt and back nut and a thrust bearing or some
washers provide the same effect?

Cheers, T i m

Fascinating things.

Can I confirm that they are like pop rivets (that is, they fit through a
hole then are pulled back to deform a tube) except that you can bolt and
unbolt things once they are set?

Pulling back done either by the bolt you plan to use, or a stronger bolt/
stud/whatever?

Again, a bit like wall plugs for fixing through plasterboard?

I assume that the major issue is keeping everything flush with the
external surface until the distortion of the tube is enough to hold
everything in place. Haven't worked the tools for that out, yet.

Cheers


dave R



--
AMD FX-6300 in GA-990X-Gaming SLI-CF running Windows 7 Pro x64

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David wrote:

Can I confirm that they are like pop rivets (that is, they fit through a
hole then are pulled back to deform a tube) except that you can bolt and
unbolt things once they are set?

Pulling back done either by the bolt you plan to use, or a stronger bolt/
stud/whatever?

Again, a bit like wall plugs for fixing through plasterboard?

Yes, you fix them blind into metalwork and they give you a threaded hole

In article ,
Peter Parry wrote:
I recently helped someone doing a lot of rivnut fixings on a frame
assembly . The tool used was from Memfast
http://www.memfast.co.uk/shop/Vcat1.asp?cat=2250003430

Tool was about £150 with a complete set of mandrels but worked very
well including for 10mm steel rivnuts (although 10mm were moderately
hard work).

I bought similar for M3 - as I said earlier all too easy to shear off the
mandrel. This type which you screw rather than compressing handles may be
slightly easier, but not foolproof. Very difficult to 'feel' the correct
setting, I found.

An ideal tool would have a foolproof way of setting the correct amount of
'pull' to set the rivnut *and* protect the mandrel.

Other thing is spare mandrels for those cost a lot more than for the mass
produced lever types.

So saying, I've never used large ones like M10. But using a spanner etc to
cut the effort down is still going to make it possible to shear the
mandrel - if the rivnut is secured to the best 'tightness'

--
*A snooze button is a poor substitute for no alarm clock at all *

Dave Plowman London SW
To e-mail, change noise into sound.

On Wed, 16 May 2018 13:26:51 +0100, Peter Parry
wrote:

On Sun, 13 May 2018 12:25:46 +0100, T i m wrote:


Should we use the special tool (again, production speeds aren't an
issue here) or can a simple bolt and back nut and a thrust bearing or
some washers provide the same effect?

I recently helped someone doing a lot of rivnut fixings on a frame
assembly . The tool used was from Memfast
http://www.memfast.co.uk/shop/Vcat1.asp?cat=2250003430

Tool was about £150 with a complete set of mandrels but worked very
well including for 10mm steel rivnuts (although 10mm were moderately
hard work).

We started by trying to use a fairly cheap pop rivet type tool but the
results were poor with some of the set nuts rotating. It was
difficult to hold the tool perpendicular to the workpiece while
applying the large force bigger nutserts required to set them. The
Memfast tool produced no failures and was easy to use.

Thanks for the feedback Peter.

Cheers, T i m

On 16 May 2018 12:31:49 GMT, David wrote:

snip

I assume that the major issue is keeping everything flush with the
external surface until the distortion of the tube is enough to hold
everything in place. Haven't worked the tools for that out, yet.

On the grounds I would be only doing 'a few' I couldn't justify a good
tool and it probably wouldn't be worth trying to use a cheap / bad
one.

So, I would turn a mandrel that had a reasonably wide foot, with a
close fitting hole for the drawing bolt and a recess turned into the
face that was not quite as deep as the thickness of the rivet nut
outer flange and just a fraction bigger ID than it.

The idea being is that the slightly shallow recess would ensure all
the effort is applied to the rivet nut itself whilst the larger
diameter of the face would help ensure everything was held true.

An HT bolt would be screwed though the mandrel and into the rivet nut
and then drawn back though using a backnut and a few washers or a
thrust bearing. This ensures that the rivet nut is just drawn into
place with little rotational force applied to the rivet nut etc.

Cheers, T i m

On 16/05/2018 13:56, Dave Plowman (News) wrote:
In article ,
Peter Parry wrote:
I recently helped someone doing a lot of rivnut fixings on a frame
assembly . The tool used was from Memfast
http://www.memfast.co.uk/shop/Vcat1.asp?cat=2250003430

Tool was about £150 with a complete set of mandrels but worked very
well including for 10mm steel rivnuts (although 10mm were moderately
hard work).

I bought similar for M3 - as I said earlier all too easy to shear off the
mandrel. This type which you screw rather than compressing handles may be
slightly easier, but not foolproof. Very difficult to 'feel' the correct
setting, I found.

An ideal tool would have a foolproof way of setting the correct amount of
'pull' to set the rivnut *and* protect the mandrel.

Other thing is spare mandrels for those cost a lot more than for the mass
produced lever types.

The nice thing about the Memfast ones is that the mandrel is just a
standard high tensile socket head screw, so cheap and easy to replace
when they are knackered. As I explained above, although the ones relying
on rotation rather than pulling are theoretically inferior, provided you
put moly disulphide on the threads they are not too bad. I've never gone
up as far as M10, though.


So saying, I've never used large ones like M10. But using a spanner etc to
cut the effort down is still going to make it possible to shear the
mandrel - if the rivnut is secured to the best 'tightness'



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On 16/05/2018 13:31, David wrote:
On Sun, 13 May 2018 12:25:46 +0100, T i m wrote:

Hi all,

Ideally this is aimed at those who have actually used 'Rivet Nuts' in a
professional / commercial environment please ...

I am considering using said to help restore a professional 'take down'
motorcycle recovery trailer where many of the fastenings would be inside
a rectangular steel box section which would make fitting nuts on the
back of machine screws complicated (I'm aware it's possible with nuts
welded to strap or spacer tubes and bolting though etc).

In most cases these fastenings would either be in shear or simply
holding a joint already under compression in place. And example would be
a tie-down 'loop' that would be fastened to either side (front and back)
of the axle tube.

So, I was wondering if these Rivet Nuts could provide a practical
solution (assuming they could replace conventional nuts etc) and if so
does anyone have any practical / personal recommendations re makes or
suppliers please?

I'm probably looking at M8/10 machine screw sizes going into ~3mm rolled
steel box and angle iron, I'd be using steel Rivet Nuts (I'm not sure
stainless Rivet Nuts would be ideal into mild steel?) and only need
10's, not 100's etc.

Should we use the special tool (again, production speeds aren't an issue
here) or can a simple bolt and back nut and a thrust bearing or some
washers provide the same effect?

Cheers, T i m

Fascinating things.

Can I confirm that they are like pop rivets (that is, they fit through a
hole then are pulled back to deform a tube) except that you can bolt and
unbolt things once they are set?

Pulling back done either by the bolt you plan to use, or a stronger bolt/
stud/whatever?

Again, a bit like wall plugs for fixing through plasterboard?

I assume that the major issue is keeping everything flush with the
external surface until the distortion of the tube is enough to hold
everything in place. Haven't worked the tools for that out, yet.

Cheers


dave R



Correct. Some have countersunk heads, so that if you countersink the
hole that they fit in you can get a flush, or almost flush, fitting. You
don't necessarily need a flush fitting, for example when fitting things
like Bridle racks or disability handles which are sort of like jam jar
lids with the screws inboard of the lip that you pull down on to.

Some rivnuts have axial ridges under the "head" to help prevent rotation
of the nut. These are particularly good if you are fixing to aluminium
sheet (as long as you drill the right sized hole, so that the ridges
have to deform the aluminium). Rotation of the nut when setting is more
a problem with the "screw" type tools (like memfast) than the "pull"
type based on pliers. But with the memfast you can reduce the risk of
rotation by putting moly disulphide on the setting screw.

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In article ,
newshound wrote:
I bought similar for M3 - as I said earlier all too easy to shear off
the mandrel. This type which you screw rather than compressing handles
may be slightly easier, but not foolproof. Very difficult to 'feel'
the correct setting, I found.

An ideal tool would have a foolproof way of setting the correct amount
of 'pull' to set the rivnut *and* protect the mandrel.

Other thing is spare mandrels for those cost a lot more than for the
mass produced lever types.

The nice thing about the Memfast ones is that the mandrel is just a
standard high tensile socket head screw, so cheap and easy to replace
when they are knackered.

Ah - right. Not the same as the wheel one I have, then. Sadly their
website doesn't seem to show them that well.


As I explained above, although the ones relying
on rotation rather than pulling are theoretically inferior, provided you
put moly disulphide on the threads they are not too bad. I've never gone
up as far as M10, though.

--
*The early bird gets the worm, but the second mouse gets the cheese *

Dave Plowman London SW
To e-mail, change noise into sound.

Dave Plowman (News) wrote:
In article ,
FMurtz wrote:
Have you actually done this? As I said a size I often use is M3. Just to
provide an easier fixing than fiddling with nuts an bolts - so access to
both sides. And haven't found 3mm screws strong enough to set it. Might
work if you can source high tensile types, though.

Yes but used high tensile and sometimes stainless threaded rod (can not
remember grade)

Where did you get high tensile threaded rod?

Don't know what the stainless was but it worked, the bolts or screws
were higher grade.

On Thu, 17 May 2018 00:30:09 +0100, "Dave Plowman (News)"
wrote:

In article ,
newshound wrote:
I bought similar for M3 - as I said earlier all too easy to shear off
the mandrel. This type which you screw rather than compressing handles
may be slightly easier, but not foolproof. Very difficult to 'feel'
the correct setting, I found.

An ideal tool would have a foolproof way of setting the correct amount
of 'pull' to set the rivnut *and* protect the mandrel.

Other thing is spare mandrels for those cost a lot more than for the
mass produced lever types.

The nice thing about the Memfast ones is that the mandrel is just a
standard high tensile socket head screw, so cheap and easy to replace
when they are knackered.

Ah - right. Not the same as the wheel one I have, then. Sadly their
website doesn't seem to show them that well.

A spinoff thought is maybe a 'better' use for some Rivet nuts may be
my upcoming wood to steel gate post swap.

They are probably ideal for mounting gate stops and hinges etc, or
possibly hinge mounting 'plates' so that I can still get some level of
adjustment (slotted holes)?

Cheers, T i m

On 17/05/2018 09:29, T i m wrote:
On Thu, 17 May 2018 00:30:09 +0100, "Dave Plowman (News)"
wrote:

In article ,
newshound wrote:
I bought similar for M3 - as I said earlier all too easy to shear off
the mandrel. This type which you screw rather than compressing handles
may be slightly easier, but not foolproof. Very difficult to 'feel'
the correct setting, I found.

An ideal tool would have a foolproof way of setting the correct amount
of 'pull' to set the rivnut *and* protect the mandrel.

Other thing is spare mandrels for those cost a lot more than for the
mass produced lever types.

The nice thing about the Memfast ones is that the mandrel is just a
standard high tensile socket head screw, so cheap and easy to replace
when they are knackered.

Ah - right. Not the same as the wheel one I have, then. Sadly their
website doesn't seem to show them that well.

A spinoff thought is maybe a 'better' use for some Rivet nuts may be
my upcoming wood to steel gate post swap.

They are probably ideal for mounting gate stops and hinges etc, or
possibly hinge mounting 'plates' so that I can still get some level of
adjustment (slotted holes)?

Cheers, T i m

Oh, you are going to use *posh* hinges then, not good old farmers gate
types which you adjust by adding washers to the pin and/or via the nuts
on the ring stud.

:-)

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On Thu, 17 May 2018 11:18:55 +0100, newshound
wrote:

snip

They are probably ideal for mounting gate stops and hinges etc, or
possibly hinge mounting 'plates' so that I can still get some level of
adjustment (slotted holes)?


Oh, you are going to use *posh* hinges then, not good old farmers gate
types which you adjust by adding washers to the pin and/or via the nuts
on the ring stud.

:-)


Well ... because the existing posts and gates are wooden, I used what
I would describe as a 'T' hinge but with pins where you could lift the
gates off but flat straps where you would fit the stud ring bolt. In
fact, mine could probably be the sort of hinges you might see on a
tailgate of a trailer. ;-)

I haven't really decided what to do with the gates yet (they are
currently just two 6' fence panels) but I was thinking of making 4 off
6' x 3' light box steel frames and having them bi-fold so I can open
them into the garden (EOT) when something is in there (trailer / car /
boat etc) without needing a complete 6' free.

I was thinking of long shoot bolts to hold each section 'stiff'
(possibly inside the box sections, giving me 18" left in each side
when closed?)) or even a single bar that slides across the back.

There is a metal 'heel' set into the ground where the current two
gates join and that takes a vertical central bolt.

Adjustable hinges (as you suggest) would make the idea of compensating
for wear and load easier.

Cheers, T i m

T i m wrote:

A spinoff thought is maybe a 'better' use for some Rivet nuts may be
my upcoming wood to steel gate post swap.

They are probably ideal for mounting gate stops and hinges etc

Keep going, you'll be talking yourself into flowdrilling next, which
will give you a good reason to buy a milling machine :-)

On Thu, 17 May 2018 21:15:59 +0100, Andy Burns wrote:

Keep going, you'll be talking yourself into flowdrilling next, which
will give you a good reason to buy a milling machine :-)

Much easier to buy a stud welder. Just stick a bolt in the machine, point it
where you want it, and pull the trigger, fixed (assuming a metal substrate here,
ok?)

Also available in portable, so cordless/rechargeable. Much *smaller* than a
milling machine, too...


Thomas Prufer