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Cap screws for aid climbing

Original Post
Jonathan Croom · · Unknown Hometown · Joined May 2015 · Points: 370

Has anyone ever seen cap screws on a gear list for an aid route? A little background: a local climber has made awesome fold out topo map guides for some crags in AZ. In a couple of the route descriptions, he lists cap screws as needed for the route. These are old, obscure 1-2 pitch aid routes at older crags. I had never heard of cap screws, and after a general (non-climbing) search it looks like basically a term for a threaded bolt. I'm guessing the routes may have some type of female drop-in anchors, but are missing the bolts, so you need to bring your own. I've never seen this anywhere else, so I was just wondering if anyone else has heard of this set up, or if it's common elsewhere. Thanks for any info anyone can share; I've been curious about this for a while.


Matt Selman · · Salt Lake City · Joined Jan 2009 · Points: 200

Occasionally you’ll find “rivet” ladders where the rivets are actually slightly oversized machine screws (cap screws, bolts, whatever) pounded into drilled holes. The screws are then slung with a rivet  hanger for upward progression. They’re cheap as hell and relatively strong, at least in shear. I placed some in a soft sandstone block in my yard and beat the shit out of them with a funkness device—the river hangers broke, but the screws are still there. 

walmongr · · Gilbert AZ · Joined Aug 2015 · Points: 120

Their are a few of these I am aware of for old aid lines at camelback. they are some sort of female drop in that takes a 1/4 or 3/8 (can’t remember) bolt that you screw in a few turns and use it like a rivet. 

Jonathan Croom · · Unknown Hometown · Joined May 2015 · Points: 370

Walmongr has the answer...I ended up climbing a couple of the routes in question, and they have 1/2" drop in anchors that take a 3/8" cap screw. The use of hex head bolts on rivet ladders is  what caused my confusion initially. I've never seen drop in anchors used anywhere as much as Camelback. I guess it was from the era of button heads, but the climbers back then were smart enough to not trust 1/4" bolts in Camelback mud. Were they used anywhere else? Old routes on desert sandstone perhaps?

As a follow up question, does anyone have tips for removing drop in anchors to reuse the holes? I'm interested in rebolting several free routes that currently have drop ins with leeper hangers. Many of the routes at Camelback have new bolts with no attempt at removing the drop ins. I've heard you can drop one or two ball bearings in then crank down a bolt in it to force the cone out the end and pull the sleeve out; anyone have luck with this? (I think these are the self drilling ones with that have a separate cone in the back) 

Guideline #1: Don't be a jerk.

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