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Minimal Cost Stainless Rap Anchor


Original Post
bttrrtRock Charles · · Unknown Hometown · Joined Jul 2014 · Points: 5

Would you rap on two of these? Why or why not?

FrankPS · · Atascadero, CA · Joined Nov 2009 · Points: 275

Is this a quiz? Trick question? Why wouldn't I rap on it?

Mae Rae · · Unknown Hometown · Joined Jan 2011 · Points: 20

You go first.

bttrrtRock Charles · · Unknown Hometown · Joined Jul 2014 · Points: 5

I'd rap on it but I bought it so...

Jeff Scheuerell · · Unknown Hometown · Joined Jan 2007 · Points: 1,625

All great except the Power bolt

Jonathan Awerbuch · · Boulder, Colorado · Joined Nov 2013 · Points: 38
Jeff Scheuerell wrote:

All great except the Power bolt

Yes I think the experts around here recommend 1/2" power bolt, especially for an anchor. The new version of the 3/8" power bolt uses a 1/4" fastener inside, which isn't nearly strong enough for climbing use.

Mike Slavens · · Houston, TX · Joined Jan 2009 · Points: 35

That is a perfectly acceptable rap anchor, and there are thousands upon thousands of anchors, both rap and at the top of sport routes, out there similar to this (although probably PS and not SS).  Some things to think about:

-304 vs 316, UIAA is recommending 316 as a minimum.  If you're going to pay for SS maybe just get 316

-That concentrates all the wear in a single spot, going with a rap ring spreads the wear over more area increasing life (although it costs more)

-Quick links and chain links tend to have much lower strength ratings than the bolt/hanger but its well above any force you could generate at a rap anchor.


bttrrtRock Charles · · Unknown Hometown · Joined Jul 2014 · Points: 5
The new version of the 3/8" power bolt uses a 1/4" fastener inside, which isn't nearly strong enough for climbing use.

I have the older ones with the 5/16" internal bolt. But just for debate here are the low specs (lowest strength concrete) for the new pb+ with 1/4" internal bolt.

17.7 kN in shear and 12.2 kN in tension. Seems pretty solid for vertical or less than  vertical bolts eh? 


Greg Barnes · · Unknown Hometown · Joined Apr 2006 · Points: 1,788

Power-Bolt (aka 5-piece) is unchanged in stainless, and the lame new design (Power-Bolt+) is not made in stainless. So if you're stainless you're fine.

Having said that, 1/2" bolts are the standard for power drill legal areas, so consider going beefier on the bolt!

Jason Todd · · Cody, WY · Joined Apr 2012 · Points: 1,119

The 3/16" quick link is pretty weak.

Here is some actual testing on some 5/16" stainless quicklinks (5/16" has 3x the cross sectional area of 3/16").  The low limit of 1500 lbs breaking is not encouraging.

http://www.supertopo.com/climbers-forum/1787466/Quick-link-load-tests-and-bad-links

bttrrtRock Charles · · Unknown Hometown · Joined Jul 2014 · Points: 5

GB - I like the idea of 3/8 five piece because when removed, the bolt hole can be enlarged if needed to 1/2 inch in the future. 

Also I wonder about how stainless corrosion will be assessed in the future and how the 3/8 vs 1/2 inch diameter will affect that assessment. 

Thought experiment:

Place one 3/8 inch bolt and one 1/2 inch bolt next to each other. Fast forward to 2067 and assume that both bolts look equally and significantly rusty. Would someone evaluating those equally rusty looking bolts want to replace only the 3/8 inch?

My thought is that most rusty bolts get replaced because they look rusty (i'm fine with that) but their usable life is much longer. Maybe the science and practice of evaluating bolts will mature in the next 50 years but I think people will still replace rusty looking bolts regardless of their diameter. 

bttrrtRock Charles · · Unknown Hometown · Joined Jul 2014 · Points: 5

Jason - I wondered when someone would chime in. Thanks for the link - good info. 

I'd rap. Would you?

Jason Todd · · Cody, WY · Joined Apr 2012 · Points: 1,119

I rap off of frozen clumps of bushes and naked threads, what I'd rap off of is probably not a good judge of what is adequate for everyone.

With a bolted anchor, there is little reason to skimp on hardware. Changing the 3/16 quicklink out for a 5/16 quicklink, would add $4 to the anchor, but dramatically improve the weakest link. Probably come out a wash if you went to a wedge anchor over the 5 pc.

eli poss · · Durango, Co · Joined May 2014 · Points: 456
bttrrtRock wrote:

Would you rap on two of these? Why or why not?

First of all, where are you getting 316 stainless chain links for a dollar apiece? That price sounds too good to be true

Also, regardless of the breaking strength or WLL, that small of a diameter isn't going to hold up well to wear and tear. While this is less of an issue with rap stations than anchors that will see lowering, think about the big picture of the lifespan of the rap station:

is it going to corrode before it sees enough use to wear out or vice versa? How long would it take it to wear out and how long would it take to become severely corroded? Unless you're climbing in an area with extremely high traffic or very abrasive particles that get into the rope, you don't want to be replacing worn hardware more than once every decade or so for a rap station.

If you're in one of these areas, however, you need to think about how much corrosion resistance you need? Are you going to get a better lifespan for your buck by using plated steel hardware that's beefier than the equivently priced stainless hardware?

If you're in a sandy desert on a trade route or classic, it might be better to get stainless bolt and hanger but then get a 1/2 plated quicklink instead of a 3/8 stainless quicklink because the hardware is going to wear out long before it ever gets corroded. If you're way out in the backcountry climbing a line that might get repeated once or twice a year, corrosion resistance may be the limiting factor instead of wear. 

bttrrtRock Charles · · Unknown Hometown · Joined Jul 2014 · Points: 5
bttrrtRock Charles · · Unknown Hometown · Joined Jul 2014 · Points: 5
Jonathan Awerbuch · · Boulder, Colorado · Joined Nov 2013 · Points: 38

I think I'm understanding the point of this thread better now -- you're looking for the lowest cost anchor that MP folks can agree on is solid. Is that right? Then what about 3/8" stainless wedge bolts instead of 3/8" powers? What kind of rock is it?

bttrrtRock Charles · · Unknown Hometown · Joined Jul 2014 · Points: 5

Ah crap your right, the links are more like $1.60.

eli poss · · Durango, Co · Joined May 2014 · Points: 456

Also,  the bolts need to be placed in a way that doesn't twist the shit out of the rope. This means you need to be either close enough horizontally that the bottom links meet or they need to be aligned vertically. One advantage of placing the bolts vertically is that one bolt will take almost all of the wear. This means you can use something really beefy on the the top bolt and then use something less beefy but adequately strong on the lower bolt, which can potentially save you money.

bttrrtRock Charles · · Unknown Hometown · Joined Jul 2014 · Points: 5
Jim Titt · · Germany · Joined Nov 2009 · Points: 490
bttrrtRock wrote:

+

$1.95 + $3.95 = $ 5.90

All 316 stainless steel, certified to EN959, breaking strength ca 38kN, made in Germany. There is a larger eye hanger available if required.

http://team-tough.com/product-category/bolts/

Guideline #1: Don't be a jerk.

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