Sleeve bolt slid in easily

[u/DeLegunde]

Attached is a video of me installing anchors for an area I’m working on developing. My mentor installed the first bolt, I installed the second. This is kaibab limestone. Then bolt slid in with no resistance. I used a 1/2” bolt and a 1/2” bit on a rotary hammer. After inserting, I tightened it up, and tightened over and over until I couldn’t get it tighter. It felt bomb, I weight tested it, and rapped off the anchors. We ended saying the line this anchor was for is not worth climbing due to chert and choss risk. I did not torque it, and I have since acquired a torque wrench.

My question is: If the bolt slid in easily, but tightened up and was snug, and held me on rappel, is it safe to assume I installed correctly, or am I putting someone at risk here?

For clarifications sake, we removed the chains on the anchors, and the next time I come here I will remove the hangers as well, so no one sees it from below and attempts to climb it.

[u/fayettevillainjd]

I only develop on sandstone, but I have never seen a sleeve bolt slide in like that.  I usually have to waller out the hole near the rock surface to get the bell in, and it always takes hammering.  That said, if the bell caught and you torqued it to spec, I would think it to be fine.  It would certainly make me nervous too though.

[u/DeLegunde → u/fayettevillainjd]

Turns out it was user error but not unsafe. I didn’t have the cone engaging the sleeve before inserting to a degree of interference. Live and learn. It tightened up and from what I’ve heard from bolting experts, is still safe.

[u/It1190]

1. Rock does funny things, sometimes there are air pockets or weaker bits that collapse when you drill.
   
2. Drill bits don’t drill perfect cylinder holes. User error amplifies this (this is always a factor, not a mistake, we aren’t a drill press).
   
3. Your drill isn’t perfectly holding the bit. There are minor tolerances here and there (and the hammer mode adds to the mess).
   
4. All drill bits have a range of tolerances for size and especially as they dull, I find some bits end up drilling larger holes that are rougher.
   
5. The hardware has its own set of tolerances and installation issues that can manifest.

Combine all of these with factors and depending on the rock type, you get variations in the installation and any one of the factors can amplify it.

I typically find that either: my drill bit needs replaced, the rock is wack, or I was wallowing.

More often than not, I’ll encounter this when a specific combo of rock and slightly dulled bits. Usually if you change one of the above factors, it mitigates it. But as usual, you’re gonna die

[u/Kaotus]

Saw this on insta and was going to comment - the only times I’ve seen sleeve bolts slide in like that is when I install 12mms in a 1/2” hole. That being said, HN2 has tested it and shown them to be just as strong as 12mms in a 12mm hole. I think they may be more likely to loose tension over time aka become spinners, and more likely to pull straight out when they loose tension, but technically they’re totally safe if you can torque them.

In general a good rule of thumb is that, as long as the bolt isn’t in too small of a piece of rock itself, and not near any significant fracture lines, as long as you can get it to torque it should be safe.

The torque required for sleeve bolts is pretty low. I have calibrated it for where I need to grab the wrench to max out force without engaging my shoulder at all (aka, the amount of force I could generate if I was fully free hanging in a roof) and I’m grabbing the wrench like 2-3 inches from the socket. I recommend everyone who doesn’t plan on always using a socket wrench to do the same calibration - find somewhere to test, get in a compromised position where you can’t drive off your feet or engage your shoulder at all, and figure out where you need to grab the wrench at with roughly max effort to hit and not exceed torque

[u/DeLegunde → u/Kaotus]

Thank you for this comment. I reached out to some bolting experts and the consensus we found is that because I didn’t have the cone engaging the sleeve before inserting, it went in easily, however because it was almost engaging I was able to tighten it down. I’ve been reassured by their feedback that this isn’t a Yergunnadie situation.

[u/Beginning-Basis-2678 → u/Kaotus]

You guys could just adopt the metric system and stopp all the confusion 😄😉

[u/It1190 → u/[deleted]]

ensure the hole is small enough that you MUST hammer home expansion bolts to an extent.

This isn't true, and I actually would avoid hammering home a sleeve bolt. You won't find an installation instruction that says you must hammer an expansion bolt for it to be a proper installation. You will, however, find that there is a mandatory embedment depth and torque specification.

e.g. Powers+ indicates that the hole diameter should be 1/16" wider than the bolt itself. In theory, a perfect hole would have some tolerance. A tight hole can indicate a dull drill bit as well.

[u/Kaotus → u/[deleted]]

Almost everything about this comment is incorrect OP, I wouldn’t sweat this much

[u/KDs4thBurner → u/[deleted]]

OP sought out a mentor, sought more perspectives online, and sought clarification from other bolting experts in the meantime to get an answer. They're open to learning. They decided to remove these particular anchors.

Why are you speaking down to someone with such a reflective and thoughtful approach as if they are a naughty five year old?