Repairing a fence for my daughter and I had to use Hilti bolts,
drilling into concrete. I've never used the things before and they
don't come with instructions.
I figured it's simple enough, drill the holes, remove the nuts, fit
the metal plate, replace the nuts on the protruding threads and tap
the bolts into the holes.
Of four bolts, three failed with stripped threads and were absolute
swines to get back out. What's the secret? Don't whack them in too
hard? Whack them in really hard? Screw the nuts down tight before
tapping them home, leave the nuts on the ends of the threads? What?
Any clues folks, the damn things are expensive and I've four more to
do tomorrow as well as the three I lost today.
Thanks for any pointers.

Harry wrote:
Repairing a fence for my daughter and I had to use Hilti bolts,
drilling into concrete. I've never used the things before and they
don't come with instructions.

What exactly do you mean by Hilti bolts? Do they look like these
http://www.toolstation.com/shop/Scre.../d90/sd/p22455

I figured it's simple enough, drill the holes, remove the nuts, fit
the metal plate, replace the nuts on the protruding threads and tap
the bolts into the holes.

Not sure what you mean by 'metal plate'?

Of four bolts, three failed with stripped threads and were absolute
swines to get back out. What's the secret? Don't whack them in too
hard? Whack them in really hard? Screw the nuts down tight before
tapping them home, leave the nuts on the ends of the threads? What?
Any clues folks, the damn things are expensive and I've four more to
do tomorrow as well as the three I lost today.

If they are sleeve anchors, these will fail if you whack them in too hard -
either the nut distorts or the thread becomes damaged - or both. Net result
is that the sleeve spins as you try to tighten them. Leave the nuts on
when you tap them in to protect the thread, use a wooden block to protect
the thread/nut. Tap rather than whack :-)

Important to drill the hole the right diameter (I assume you have) and the
right depth and clear the dust out.

Sleeve anchors are cheap as chips from places like Toolstation or Screwfix -
M10 x 100 for example are £5+ for a pack of 6 in Wickes, but £2.52 for 10 at
Toolstation.

Even better, forget sleeve anchors & use masonry bolts
http://www.toolstation.com/shop/Scre...ors/d90/sd2040


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk

"The Medway Handyman" wrote in message
news:IqfNn.279$jL2.130@hurricane...
Harry wrote:
Repairing a fence for my daughter and I had to use Hilti bolts,
drilling into concrete. I've never used the things before and they
don't come with instructions.

What exactly do you mean by Hilti bolts? Do they look like these
http://www.toolstation.com/shop/Scre.../d90/sd/p22455

I figured it's simple enough, drill the holes, remove the nuts, fit
the metal plate, replace the nuts on the protruding threads and tap
the bolts into the holes.

Not sure what you mean by 'metal plate'?

Of four bolts, three failed with stripped threads and were absolute
swines to get back out. What's the secret? Don't whack them in too
hard? Whack them in really hard? Screw the nuts down tight before
tapping them home, leave the nuts on the ends of the threads? What?
Any clues folks, the damn things are expensive and I've four more to
do tomorrow as well as the three I lost today.

If they are sleeve anchors, these will fail if you whack them in too
hard - either the nut distorts or the thread becomes damaged - or both.
Net result is that the sleeve spins as you try to tighten them. Leave
the nuts on when you tap them in to protect the thread, use a wooden block
to protect the thread/nut. Tap rather than whack :-)

Important to drill the hole the right diameter (I assume you have) and the
right depth and clear the dust out.

Sleeve anchors are cheap as chips from places like Toolstation or
Screwfix - M10 x 100 for example are £5+ for a pack of 6 in Wickes, but
£2.52 for 10 at Toolstation.

Even better, forget sleeve anchors & use masonry bolts
http://www.toolstation.com/shop/Scre...ors/d90/sd2040


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk

I just used 12mm stainless threaded rod. Concrete into the ground with the
nuts already on and through the plate, then tighten nuts when it's set.

S

The Medway Handyman wrote:
Harry wrote:
Repairing a fence for my daughter and I had to use Hilti bolts,
drilling into concrete. I've never used the things before and they
don't come with instructions.

What exactly do you mean by Hilti bolts? Do they look like these
http://www.toolstation.com/shop/Scre.../d90/sd/p22455


In my book a Hilti Bolt is synonymous with a Rawl bolt, i.e. a
traditional shield anchor.

http://www.hilti.co.uk/holuk/page/mo...&nodeId=-86796


http://www.rawl.com/index.php?option...19&Itemi d=25

I figured it's simple enough, drill the holes, remove the nuts, fit
the metal plate, replace the nuts on the protruding threads and tap
the bolts into the holes.

Not sure what you mean by 'metal plate'?

Whatever he's bolting down with the anchor, presumably.


Of four bolts, three failed with stripped threads and were absolute
swines to get back out. What's the secret? Don't whack them in too
hard? Whack them in really hard? Screw the nuts down tight before
tapping them home, leave the nuts on the ends of the threads? What?
Any clues folks, the damn things are expensive and I've four more to
do tomorrow as well as the three I lost today.

Not sure how OP managed to strip threads!

To the OP:

The technique for a shield anchor is firstly to drill the correct size
and depth of hole.

Next, get all the dust and crap out of the hole. Try not to blow into it
unless you have goggles on.

Next, make sure the "expanding" part of the anchor is loose, otherwise
the anchor won't go in the hole.

The anchor should slide easily into the hole. If it doesn't, undo the
nut sufficiently that it protects the threads on the end of the bolt and
then gently tap the anchor into the hole until the body of the anchor is
flush or slightly recessed. This is by way of a playful love-tap. If you
have to force it, then either the hole's too small or you didn't clean
the crap out.

Remove the nut and washer; offer up the plate (or whatever) to the
projecting stud; replace the washer and nut.

Tighten the nut by hand. The anchor should bite before the nut is too
difficult to tighten by hand. If the whole anchor rotates in the hole,
then you have to assist the anchor to get started. Using a pair of Mole
grips, pliers or somesuch to stop the bolt from rotating whilst you use
a spanner on the nut should get the action of the anchor started.

Once friction has got a start, you can tighten the nut with a spanner,
socket or (my favourite) a ratcheting ring.

Job's a goodun.

Tighten the nut by hand. The anchor should bite before the nut is too
difficult to tighten by hand. If the whole anchor rotates in the hole,
then you have to assist the anchor to get started. Using a pair of Mole
grips, pliers or somesuch to stop the bolt from rotating whilst you use
a spanner on the nut should get the action of the anchor started.

Once friction has got a start, you can tighten the nut with a spanner,
socket or (my favourite) a ratcheting ring.

Job's a goodun.

Brilliant! Many thanks for the responses. Dave guessed closest and
sorry, I was a little vague - end of a long, wet, hard day and just
crawled from a Radox bath prior to staggering off to bed. They're
rawbolts, just I've always known those sort of fittings collectively
as "Hilti bolts" - from the days when I'd watch the shop floor fitters
using them.
The thread which is stripping is at the bottom of the bolt itself,
where it passes into the last component, shaped sort of like an old
Apollo crew capsule. Yes, the holes are correct size, dust is out and,
initially force wasn't used. When the nuts wouldn't tighten I used
gentle force and when that didn't work, ended by hammering them down.
If I'd know about masonry bolts I'd have used them, but as I've now
got four 10mm holes I think I'm stuck with what I've got - although I
will be getting new items from the local Screwfix.
Many thanks again.

Thanks to your reponses I bought replacement fixings from Screwfix -
£4.40+ for five as opposed to Focus, which is much closer, who charged
£9+ for two. A dry fit proved that the bolt was too long - I'm unable
to drill deeper - but hacksawing 1/2" off sorted it and this time the
things worked perfectly. Metal plate bolted down solidly and fence
repair complete.
Everyone's advice much appreciated, pints all 'round ;-

Harry wrote:
Thanks to your reponses I bought replacement fixings from Screwfix -
£4.40+ for five as opposed to Focus, which is much closer, who charged
£9+ for two.

What size were they Harry? SF part number?


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk