I have acquired some bolts!

🔗Personal-Album-2-Image-51108[linkphoto]Personal-Album-2-Image-51108[/linkphoto][/link]

From left:
- Fixe bolt & hanger
- Fixe hanger with industrial bolt
- Petzl bolt & hanger

All are 12mm

It's quite interesting how short the Petzl bolt is - and similarly how long the bolts that I sourced separately from the hangers are.

It seems logical to have more bolts than hangers as the hangers can be reused - hence I've bought a box of 25 of the longer bolts.

Question: is there going to be any problem with installing the longer bolt in a similar depth hole to the 'standard' Fixe bolt and just having more thread sticking out?

I can see no problem, although there may be some benefit in installing it deeper as that would reduce the odds of the rock failing.

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To my mind the 'climbing' fastenings actually look shorter than I'd like to use so I'd use the industrial fixings and drill as deep as possible, yes this will be stronger. I’m going to have a go at grinding some drills bits especially for slate, what diameter are your fixings? They will be rotary only and won’t fit an SDS drill.

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Cheers, they're 12mm bolts - might be worth checking with Simon to see what drive his drill uses though as that's what I'm intending to use!

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Cheers, they're 12mm bolts - might be worth checking with Simon to see what drive his drill uses though as that's what I'm intending to use!

SDS 🙂

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Oh well, just finished grinding it up, I'll find an SDS bit to grind up, my brother's nicked all mine at the moment.

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The long bolts that dont hold the expansion sleeve in place can be a bit of a pain. We have had quite a bit of trouble with them as they tend to start to rotate when you undo them.
This makes them somwhat more exspensive as each one uses an entire hanger 😞.
The fischer ones seem to be much better. We shall see in time.

You can sometimes prevent such bolts rotating if you do them up really tight first and then keep an outward load on the hanger as you undo them to keep the wedge engaged.

It's also possible to hacksaw a slot across the end of the bolt before use so that a screwdriver can be used to stop the bolt rotating.

In either case, using grease on the bolt before use helps to prevent the nut seizing to the bolt and causing it to rotate.

I'm afraid none of these ideas help much if you're trying to deal with an in situ bolt when the nut has seized to it. :)

Dave

I have acquired some bolts!

🔗Personal-Album-2-Image-51108[linkphoto]Personal-Album-2-Image-51108[/linkphoto][/link]

From left:
- Fixe bolt & hanger
- Fixe hanger with industrial bolt
- Petzl bolt & hanger

All are 12mm

It's quite interesting how short the Petzl bolt is - and similarly how long the bolts that I sourced separately from the hangers are.

It seems logical to have more bolts than hangers as the hangers can be reused - hence I've bought a box of 25 of the longer bolts.

Question: is there going to be any problem with installing the longer bolt in a similar depth hole to the 'standard' Fixe bolt and just having more thread sticking out?

I can see no problem, although there may be some benefit in installing it deeper as that would reduce the odds of the rock failing.

There was something on Ukcaving saying that cavers had knicked some bolts that climbers has put into a rock face in a quarry. I hope you have a receipt 😉

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Cheers, they're 12mm bolts - might be worth checking with Simon to see what drive his drill uses though as that's what I'm intending to use!

SDS :)

Got a specially sharpened SDS drill now, it's for use with rotary only, hammer turned off. Don't think it'll be up to Mr Kellow's 6' in 1 1/2 minutes but still should be a lot quicker than a normal drill.

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Got a specially sharpened SDS drill now, it's for use with rotary only, hammer turned off. Don't think it'll be up to Mr Kellow's 6' in 1 1/2 minutes but still should be a lot quicker than a normal drill.

:thumbsup:

I feel a test coming on!

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Got a specially sharpened SDS drill now, it's for use with rotary only, hammer turned off. Don't think it'll be up to Mr Kellow's 6' in 1 1/2 minutes but still should be a lot quicker than a normal drill.

:thumbsup:

I feel a test coming on!

Give me a bit long enough and I'm sure the Hilti will come a poor 2nd in that test :lol:

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Got a specially sharpened SDS drill now, it's for use with rotary only, hammer turned off. Don't think it'll be up to Mr Kellow's 6' in 1 1/2 minutes but still should be a lot quicker than a normal drill.

:thumbsup:

I feel a test coming on!

Give me a bit long enough and I'm sure the Hilti will come a poor 2nd in that test :lol:

Not sure we have Mr.Kellow's drill to test... :bored:

:lol:

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Not in this league yet then. 😉

"But John Henry made fifteen feet;
The steam drill only made nine"

Our strong preference from putting in about 1000 bolts in the last 6 years is to use HILTI HSA M10 / 20 /25. These have a paint mark on them to show the minimum amount they need to go into the rock.

For drill bits buy top quality SDS ones from Bosch and DeWalt - they drill better and you need to carry fewer batteries.

Got a specially sharpened SDS drill now, it's for use with rotary only, hammer turned off. Don't think it'll be up to Mr Kellow's 6' in 1 1/2 minutes but still should be a lot quicker than a normal drill.

:thumbsup:

I feel a test coming on!

Give me a bit long enough and I'm sure the Hilti will come a poor 2nd in that test :lol:

Not sure we have Mr.Kellow's drill to test... :bored:

:lol:

No, you only get a special drill bit from me, Simon will still need to carry his cordless Hilti 😉

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No, you only get a special drill bit from me, Simon will still need to carry his cordless Hilti 😉

Cordless?

*raises one eyebrow*

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No, you only get a special drill bit from me, Simon will still need to carry his cordless Hilti 😉

Cordless?

*raises one eyebrow*

Well don't forget an extension lead then 😉

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Not in this league yet then. 😉

"But John Henry made fifteen feet;
The steam drill only made nine"

"Though many tried, no double-jack driller succeeded in breaking John Henry's apocryphal record of driving fourteen feet of steel in hard rock in thirty-five minutes. For two generations or more, giant men, masters of wielding heavy hammers, met in drilling tests each year in the West, from El Paso to Butte. Hand-drilling as performed by such champions as the Tarr brothers from Idaho Springs, or 'The Turrible Swedes' from Ouray was a precision sport which required as much careful preparation and training as a prize fight. Tens of thousands of dollars changed hands in betting and prize money, and no record was recognised unless made in Gunnison granite from Colorado. Large blocks of this standard granite were therefore shipped to the scenes of the great drilling contests.

The contests were run in fifteen minute sets: double-jack teams used 7/8-in steels and single jack performers 3/4-in jumpers. Since the steels dulled after a minute or so, changing steels became a sleight of hand performance, the shaker removing the dulled steel and putting in a new one between two blows without the hammer men slowing down the beat of ninety blows per minute. Likewise, members of a two-man team changed places in a split second, the hammer not missing a beat during the fiftee-minute match.

Many amazing records were set. The Tarr brothers sank 44 in. to become El Paso champions in 1903; Kinsella and McLean beat that record with 46 5/8 in. at Bisbee the same year. At Butte in 1912, the Tarr brothers seem to have set an all-time record of 59.5 in. The single-jack record set at the same drilling meet was 45 1/16 in., obtained with a beat of 144 strokes per minute.

But such drilling skills were not for sale to mine operators and tunnel contractors. They had to be satisfied with far slower performance, but it nevertheless took many years before manual drillers admitted defeat by the machines."

G.E.Sandstrom "The History of Tunnelling", London, 1963, pp.100-101.

Our strong preference from putting in about 1000 bolts in the last 6 years is to use HILTI HSA M10 / 20 /25. These have a paint mark on them to show the minimum amount they need to go into the rock.

For drill bits buy top quality SDS ones from Bosch and DeWalt - they drill better and you need to carry fewer batteries.

Cheers Jon :)

I found the 12mm hangers easier to source this time round, but I'd probably concur that 10mm would be preferable, presumably with improved battery life being a decent consideration?

I'm hoping to gain a cheap source for hangers in the nearish future, so 10mm will probably be the next batch.

I guess there's an oddity in that the major sellers (Petzl and Fixe spring to mind) sell bolts & hangers; or hangers along (presuming you buy the bolts elsewhere). Yet they don't appear to sell bolts on their own, which is something of an oddity given you can reuse hangers but not (often) bolts.

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Interesting reading about the hand drilling and granite's a lot harder than slate, thse times are truly remarkeable. Slate's nice because it machines well without hammering, you just need to be able to push the drill into the rock, easy by hand with a 12mm hole a few inches deep but an inch diameter and six feet deep more of a challenge withpout a nearby wall or machine to brace against!

It'll be embarasing if the standard SDS hammer bit is quicker than mine!

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