Author Topic: Backcountry wall bolts  (Read 1543 times)

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Offline mungeclimber

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Backcountry wall bolts
« on: July 04, 2006, 09:32:13 pm »
Also posted on supertopo...

Anyways, saw this...

http://www.powers.com/pdfs/mechanical/03601.pdf

The optimum bc bolt would be what I used to know as a 5/16" Rawl Drive.

Now it appears the size is 3/16".

Has anyone actually purchased this sized bolt, and used it in conjunction with a bit; precisely what sized bit? I would assume it now should be a 3/16" bit. Anyone seen a 3/16" SDS carbide tip bit in use out there? 2" or 4"

e.g. http://power-tools.hardwarestore.com/54-383-hammer-drill-bits/sds-carbide-tip-bit-669510.aspx

Offline deuce4

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bolts
« Reply #1 on: July 05, 2006, 02:10:31 pm »
3/16 " is too small--I wouldn't trust them.

1/4" split shank type bolts are light, fast to place, and do work; but as is now known, they work only for a decade or two.

Looks like Powers is making a 5/16" "Power-bolt" (looks the same as the Rawl-bolt).  In 2" length, these rate to over 3000 lbs (tension) in 4000psi concrete.

http://www.powers.com/pdfs/mechanical/06914.pdf

Could be worth a test.

By the way, if you have one of the old Hurricane Drills, you can still buy any collet for any drill size--generally you will add 1/64" to 1/32" to the bolt size for the drill size, e.g to drill 1/4" bolts, you might drill with a 17/64" or a 9/32" drill, depending on the rock (If you measure SDS bits, you will find that they conform to this formula--the 3/8" SDS bit is actually around 25/64", if I recall correctly).

The address for buying the stock 200DA collets in  1/64" increments (or metric) for the Hurricane drill are in my old 1996 A5 catalog, which can be found as a pdf on bigwalls.net  I think McMastercarr.com also has them, but you may need an account.

cheers
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Offline Craig Peer

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Backcountry wall bolts
« Reply #2 on: July 05, 2006, 03:03:07 pm »
Quote
3/16 " is too small--I wouldn't trust them.

1/4" split shank type bolts are light, fast to place, and do work; but as is now known, they work only for a decade or two.


Amen. 1/4" is small enough!!

Offline mungeclimber

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Backcountry wall bolts
« Reply #3 on: July 05, 2006, 05:36:08 pm »
yeah, I flubbed on this post, i didn't pay attention in math apparently.

I was just too excited to see the drives at all.

I guess I have the last 10-20  5/16" drives on the planet.  Like gold. Wonder if my newer SDS 5/16" bit will actually create a good hole for these.  Haven't had a chance to try them out yet.