Multi Montis
- Thread starter Madness
- Start date
Simon Wilson
New member
7.5 x 80 or 70 are perfect. Only use reputable good quality brands such as Multi Monti, Fischer, Rawlbolt or Hilti.
Do not use the cheap ones such as Thunderbolt, Ankerbolt, Lightningbolt, Excalibur, DeWalt.
I have done some research into these 'concrete screws' and I have confidence in the first four brands. Some of the cheapo ones have no ETA, some have ETAs which do not specify an identifiable country of manufacture and some are made in developing countries where adherence to standards is not as well guaranteed.
(ETA = European Technical Assessment)
Multi-Monti ETA : https://www.asf-fischer.nl/files/artikel_documentatie/dop/ETA-05-0010_en.pdf
Even the most expensive ones cost pennies each so don't even think about reusing them for SRT; there is no point even if you think it looks OK.
You can reuse them in non-critical uses such as hauling boulders, fixing shoring etc.
Use galvanised ones and consider stainless ones of they are going to be there a long time.
I am keen to see people use 'self-tapping concrete anchors' because they are removable. Please do not install any anchor in a cave which is not removable.
Do not use the cheap ones such as Thunderbolt, Ankerbolt, Lightningbolt, Excalibur, DeWalt.
I have done some research into these 'concrete screws' and I have confidence in the first four brands. Some of the cheapo ones have no ETA, some have ETAs which do not specify an identifiable country of manufacture and some are made in developing countries where adherence to standards is not as well guaranteed.
(ETA = European Technical Assessment)
Multi-Monti ETA : https://www.asf-fischer.nl/files/artikel_documentatie/dop/ETA-05-0010_en.pdf
Even the most expensive ones cost pennies each so don't even think about reusing them for SRT; there is no point even if you think it looks OK.
You can reuse them in non-critical uses such as hauling boulders, fixing shoring etc.
Use galvanised ones and consider stainless ones of they are going to be there a long time.
I am keen to see people use 'self-tapping concrete anchors' because they are removable. Please do not install any anchor in a cave which is not removable.
Simon Wilson
New member
They don't. You need to use a hanger with a bigger hole.Rob said:
If you want to use smaller screws that's up to you but I'd rather use a slightly bigger hanger.
andrewmcleod
Well-known member
These should be pretty removable if you are only aiding upwards... (with an occasional proper bolt!) 
http://www.bolt-products.com/StainlessSteelPitons.htm
http://www.bolt-products.com/StainlessSteelPitons.htm
Madness
New member
andrewmc said:These should be pretty removable if you are only aiding upwards... (with an occasional proper bolt!)
http://www.bolt-products.com/StainlessSteelPitons.htm
Thanks for the link. They're dirt cheap. Anyone on here ever used them?
Mattrees
Member
Madness said:andrewmc said:These should be pretty removable if you are only aiding upwards... (with an occasional proper bolt!)
http://www.bolt-products.com/StainlessSteelPitons.htm
Thanks for the link. They're dirt cheap. Anyone on here ever used them?
They scare me.
Does anyone have a source for 7.5mm (6mm hole) stainless anchors?
Mattrees said:
I've been using through bolts for climbing but it may be a good idea to use screw-ins as they can be screwed out again, not so much to re-use them but so bolts aren't left behind all the way up a wall. I always over drill the holes for through bolts so they can be tapped in afterwards and covered by a little mud.
I'm a bit confused as to what hole diameter is required for a particular size of screw-in bolt. Am I right in thinking that 6mm bolts actually need a 5mm hole, rather than 6mm as alluded to in the quotes above and the 7.5mm bolts need a 6mm hole? Don't understand why 7.5mm bolts don't fit in 8mm hangers.
Any help in clearing this up would be much appreciated, thanks.
pwhole
Well-known member
I'm not familiar with that particular brand, but they generally all need a bigger hole in the hanger plate than the rock, as the thread projects to a greater diameter than the shank. An 8mm bolt actually has a thread diameter of about 9mm, so you have to use a 10mm plate. Incidentally, premium Hilti screws are not exactly cheap, at ?1.78 per pop:
https://www.hilti.co.uk/anchor-systems/screw-anchors/r3241612
https://www.hilti.co.uk/anchor-systems/screw-anchors/r3241612
Mattrees
Member
Huge said:
Different manufacturers list them in different ways, some will list by drill bit diameter, others by thread clearance (hanger) diameter. I'm using Thunderbolts, these are usually listed (but not always) by bit diameter. I'm drilling 6mm holes and using 8mm hangers.
The Hilti ones are very expensive, I'm still looking for a reasonably priced source of stainless anchors.
Cheers Mattrees.
I found the Multi Monti bolts listed at InterTools, who are based at Ilkeston in Derbyshire. They only list 6mm and 7.5mm, which must be the outside diameter of the threads, with the shafts of the bolts being 5mm and 6mm respectively. I suppose the size of bolt you are using would be their 7.5mm.
http://www.intertoolsonline.co.uk/heco-schrauben/fixings/masonry-and-concrete/multi-monti/multi-monti-hex-head-range
I found the Multi Monti bolts listed at InterTools, who are based at Ilkeston in Derbyshire. They only list 6mm and 7.5mm, which must be the outside diameter of the threads, with the shafts of the bolts being 5mm and 6mm respectively. I suppose the size of bolt you are using would be their 7.5mm.
http://www.intertoolsonline.co.uk/heco-schrauben/fixings/masonry-and-concrete/multi-monti/multi-monti-hex-head-range
SamT
Moderator
Yes, I sometimes equip climbing routes with these initially, with a view to replacing them with proper resins once the route is worked and established.
The advantage is that if the initial placement is not quite in the right place for easy clipping, its straight forward to just unscrew and move. Once the right place is found, the same hole can be re-drilled larger, and a resin bolt installed.
I've always found that I can get the 8mm (drill size) ones, through a normal petzl hanger with a 10mm hole no problem. I had some larger 10mm ones that would go through a 12mm hanger, but had to be screwed on over the threads.
Has anyone thought of/tried using an impact driver to place these?
The advantage is that if the initial placement is not quite in the right place for easy clipping, its straight forward to just unscrew and move. Once the right place is found, the same hole can be re-drilled larger, and a resin bolt installed.
I've always found that I can get the 8mm (drill size) ones, through a normal petzl hanger with a 10mm hole no problem. I had some larger 10mm ones that would go through a 12mm hanger, but had to be screwed on over the threads.
Has anyone thought of/tried using an impact driver to place these?
pwhole
Well-known member
I've used an impact driver at work on them, driving into concrete, though the first batch of screws we were given were so cheap and nasty I ended up taking in some of my Excaliburs the next day, which worked fine. Cleaning the holes our properly is critical unless they're massively over-drilled, as it's the dust that jams/blocks them. My main concern with the impact driver is not being able to 'feel' the rock like a hand-driven one, so any holes or weaknesses may not be as apparent. That said, I did some bolt-climbing with them recently, and screwing them in at full stretch perfectly perpendicular to the hole was not easy at all, and one or two ended up getting jammed, so had to pull out and re-screw. So I can see for climbing, an impact driver (especially one with torque control) might actually help quite a lot, though a lot more expensive than a ratchet spanner.
