Fast process for buttonhead removal

@JabroniMcChufferson Kudos to your party! The Needle ridge approach and climb are no joke! I hope you had a safe long day. How did you like clipping that ring piton on pitch 3?

Super fun climbing! Dropping into that canyon and thrashing to the base certainly makes for the adventure, and the yucca? plants on pitch 5? Out of the isn’t notch if I remember correctly. Reminded me of something similar  of the wheeler crest/ eastern sierra or southern sierra.

Greg Barnes wrote:

Hey Kevin, how many 5/16" buttonheads holes have you tried to hand drill to 3/8"? It's super hard since the old holes are nearly 3/8" or so in the "wide" direction (where the split shaft went in), and the bits get SUPER stuck really easily. You can even tear the grip off of hand drills trying to rotate since most of your time is trying to rotate to break out rock. I think with modern 4-cutter bits (the ones that are symmetrical + shaped), it might be possible, but it was nearly impossible with older bits (including the Bosch Bulldog Xtreme bits that the ASCA has been supplying for years - those are solid carbide head but not symmetrical + shaped). 

In Tuolumne a few times I would size up to 12mm and place Long-Lifes, since they were really short. Hand drilling up to 12mm was doable, while the 3/8" bits would always get stuck.

This can be strongly affected by exactly how hard the rock is and how much it spalled when the 5/16" was driven in. And also whether people had drilled true 5/16" holes, or oversized holes (it was common for folks to use slightly oversized bits in granite since you often couldn't get a 5/16" buttonhead to go into a 5/16" hole in hard granite).

Greg,

Have you ever tried redrilling a 5/16 hole with a self drive (O.D. 12mm). Back in the pre-power drill days that was a easy upgrade for a 1/4 bolt. In very hard quartzite a 1/4 " hole could be upsized with very ordinary effort.

I imagine there would not be the problems of the bit getting stuck like with drilling out the 5/16 with 3/8. 

There are some options availible now for 12mm short bolt that were not availible in the mid 80s .

I have been thinking of what to do about  old self drive bolts in our Linville Gorge Wilderness. There are not many 5/16 Rawl drives( button heads in NC. 

For chuckles i drilled a 5/16 hole in a chunk of quartzite here, then drilled it out by hand with a self drive. 12mm O.D. by 48 mm deep. It is relatively easy to do. Much easier than drilling any diameter hole from scratch. Both of my Petzl self drive holders have a reduced diameter portion so that you can drill the 12mm deeper than the length of the self drive. Probably for placing the Long Life bolts?

Next i will post a bolt i am thinking about.

When browsing Oliunid's site I found these 316L Sleeves meant to be put in a self drive hole for caving. You could attach a hanger with an 8mm bolt, but that would only have around 3000 lb shear strength. Not really what we want. Then I went shopping for 12mm  diameter Shoulder bolts. I found numerous material and length options from McMaster-Carr . 316 is available.  The thread in the sleeve is standard pitch 8mm. Pictured bolt is a lower grade SS just for playing around. It has a 14mm  long shoulder. The hole I drilled with the pictured Petzl holder was 48mm deep with the self drive shown. Length of the SS sleeve is 31mm.

I am confident this bolt would meet our strength standards with the 14mm or longer shoulder bolt. This might be a good solution for upsizing a 1/4", 5/16", or small self drive by hand drilling in wilderness or generic Alpine. 

timothy fisher wrote:

When browsing Oliunid's site I found these 316L Sleeves meant to be put in a self drive hole for caving. You could attach a hanger with an 8mm bolt, but that would only have around 3000 lb shear strength. Not really what we want. Then I went shopping for 12mm  diameter Shoulder bolts. I found numerous material and length options from McMaster-Carr . 316 is available.  The thread in the sleeve is standard pitch 8mm. Pictured bolt is a lower grade SS just for playing around. It has a 14mm  long shoulder. The hole I drilled with the pictured Petzl holder was 48mm deep with the self drive shown. Length of the SS sleeve is 31mm.

I am confident this bolt would meet our strength standards with the 14mm or longer shoulder bolt. This might be a good solution for upsizing a 1/4", 5/16", or small self drive by hand drilling in wilderness or generic Alpine. 

timothy, 

While that an interesting idea and excellent sourcing of materials, I don't see what improvement that makes or what problem that it solves. What am I missing?

The SS anchor, pictured, is a drop-in anchor, external plug type. To be used properly, it requires a specific depth hole. Alternatively, internal plug drop-in anchors are readily available in construction products, incl. Hilti, Powers, and Red Head. The 3/8" size requires drilling a 1/2" x 1-9/16" hole for the drop-in. Install by hammering on a setting tool. Attach the hanger with a 3/8" hex head bolt. Not that I would recommend drop-in anchors for any climbing protection or anchor purpose. Drop-ins are perfect for attaching artificial climbing holds to concrete walls. There are stronger and more reliable types of anchors than drop-ins. Other than for caving, is anyone advocating for the use of "self drilling" or drop-in anchors for rockclimbing? I thought those went out of fashion in the 1980s. 

The idea of a shoulder bolt gives the visual appearance of meeting your objective for additional strength. However, shoulder bolts have their disadvantages and strength limitations. The transition from the threaded portion to the shoulder portion is necked down to narrower than the root of the threads. This makes it weaker than the threaded portion!  My sand rail's suspension sheared a few shoulder bolts, and always where the shoulder meets the threads. Over torquing is another cause of failure at that weaker point. Torque values must be reduced to compensate. Torque values for stainless steel are also reduced, as would the addition of any lubrication, therefore, torque specs should be carefully calculated. See "Thread Specs --> Thread neck"   here: https://www.machinedesign.com/fastening-joining/article/21834322/the-basics-of-shoulder-screws

Why not simply use a SDS bit to drill and install a sleeve anchor or wedge anchor? It requires a few extra minutes to drill a deeper hole. The idea should be to improve the strength of the anchor if going to the effort of replacing old bolts. I would trust my 1980s-1990s  5/16" buttonheads before trusting a drop-in anchor.

Climbbaja

I suggested this here because of the difficulty of drilling out the hole left by 5/16 Rawl drive.

I fully promote re-using holes when practical, and hope what I suggested may help.

Self drives were in common usage here in the east pre-power drill. I have experience upgrading 1/4 bolts to self drives pre-power drill. I expected that drilling out the 5/16 hole with a self drive would not be not be a problem. It certainly did not present an issue on one I did yesterday.

Once the the old hole is drilled out the 12mm hole could be extended using an sds bit. If i were doing the work I would prefer to finish the hole in one go with one tool. There are SDS adapters for self drives that could allow a quick change using one holder.

Any sort of 12mm bolt could be used. I dont know of any commonly used  currently availible 12 mm bolt that would fit in the 48mm deep hole my Petzl tool could make. 

As someone who has successfully removed dozens of self drive sleeves, the holding power in tension of these sleeves is not in question. Their unsuitability for climbing is in shear strength and lack of corrosion resistance. In that, they are no less suitable than 5/16 Rawl drives. I am not promoting either.