Bolt Identification

Found one! This is an identical Bachar taper eye bolt from Grenade Launcher (assuming he didn't find and use multiple lengths - very unlikely). 2.25" 5-piece on left, 2.25" stud bolt on right, plus an 8x80mm Raumer Antrax (which are fine in 3/8" holes). The sleeve (which I guess is a zinc alloy, I'd always been told it's lead) starts 1 5/8" down, and the entire bolt length is 2.5" (starting at the rock surface, the tapered end is just shy of 2.5" so I'm assuming the bottom of the sleeve - aka minimum hole depth - has to be 2.5" or so). When I placed an identical stud bolt in one of the holes of the anchor of Grenade Launcher, the bolt hit the sleeve with maybe 1/4" of threads sticking out above the nut, so when tightening it's a really minimal margin of error for the sleeve to engage.

Side note - stud/wedge bolts length is the overall length of the bolt, and 5-piece length is measured below the washer, which is why you drill a lot deeper for a 2.25" 5-piece!

I’ve used the eggbeater hand drill to drill out the lead sleeve on these before. It worked well and total replacement time was about 10 min. Use cheap HSS drill bits because you’ll destroy them on the rock. I used a little water in the hole to keep any dust from forming. Then used a gold mining (sucker) bottle with a small tube to flush the hole clean with water. I don’t know the composition of the alloy, but I always thought it was a lead/zinc/bismuth mix to be a bit harder than just pure lead. Unless you’re positive the alloy, I’d be on the safe side. There will be a bit of metal left in the hole when done drilling from the cone shape of the drill bit. Sometimes it comes out, sometimes not. So just start hand drilling slow with light taps to dig through. Only takes a couple turns and you’re off to whacking away, if you even need to hand drill deeper in the first place. Works for those lead sleeve “drop in” machine bolts too. Though I don’t run across those too often. 

Greg's pic is great!! You can see that you only need to get about half of the zinc alloy sleeve out of the hole to have enough room for a bomber (3/8X2 1/4") 5 piece. On a slab you could cut down a Bolt-Products 8mm SLB to 2 " and be fine with no additional work! Still worth the effort to get all the old bolt out and start fresh!

If i was not on the East coast I would love to help you folks upgrade these historic routes! This Forum is so cool!

OK so here are some updates.

Just for clarification to all, the cone/sleeve is made of zamak 3, a zinc alloy. It is not made of lead.

Because this is for a Wilderness location, I am using only Wilderness appropriate hand tools. No power tools, power drills, grinders, torch cutters, etc. will be permitted for use in the real situation, so I shall not use them in my experiment.

Goal: Remove all trace of 3/8" taper bolts, be able to drill hole deeper and reuse for better bolts

Useful tools:

• Hammer
• Wrench
• Rock hand drill
• Regular "2-cutter" 3/8" masonry bit
• Special "4-cutter" 3/8" masonry bit
• Bit brace (hand crank drill)
• 5/16" titanium nitride coated drill bit
• 3/8" titanium nitride coated drill bit
• Blow tube
• Hole brush
• Needle nose pliers

Removal process - This is the process that I found had the highest likelihood of success and took the least time

1. Unscrew the stud. The sleeve will stay in place at depth.
   • Probe the depth to the sleeve. The sleeve does have a hole in the middle so if you're not paying attention you might be probing through the center. If the hole is deep enough to accommodate your new SS bolt and you don't want to remove this old junk, proceed with the new bolt installation. Otherwise continue with step 2.
2. Using bit brace fitted with 5/16" ti nitride bit, drill through the center of the sleeve. The zamak 3 is soft and with a sharp bit you should feel it catch and drill through quickly and start spinning freely.
3. Using bit brace fitted with 3/8" ti nitride bit, drill through the center of the sleeve.
   • In all my testing, with newly emplaced bolts, the bit would always dig down about half way into the sleeve before the sleeve began spinning in the hole.
4. Slowly pull the bit out, still rotating, until you have pulled the sleeve out of the hole in one piece.
5. Use your blow tube to clean the metal debris from the hole before using your hand drill to drill your hole to your preferred depth.

Issues and how to deal with them

Sleeve spinning freely in the hole, unable to pull out with drill bit

• If you can reach the sleeve with needle nose pliers, grab it an pull it out
• If you have exhausted all attempts to drill out with ti nitride bits and extract with pliers... do this
  1. Use rock hand drill fitted with a 4-cutter 3/8" masonry bit to tap the sleeve to the bottom of the hole. Do not smash it in, just tap it to the bottom. The 4-cutter will be much less likely to lodge or become embedded in the soft metal of the sleeve.
     • As before, probe the depth to the sleeve. The sleeve does have a hole in the middle so if you're not paying attention you might be probing through the center. If the hole is deep enough to accommodate your new SS bolt and you don't want to remove this old junk, proceed with the new bolt installation. Otherwise continue with step 2.
  2. Using bit brace fitted with 3/8" ti nitride bit, drill through the center of the sleeve.
  3. If it catches or just drills through, remove as per the normal process. 

You can't get the drill bit to catch but you're sure there's still some sleeve in there

• If you feel like you've tried everything above...
  1. Using your hand drill with your 4-cutter masonry bit, gradually smash the sleeve into a crumpled mess at the bottom of the hole
     • As before, probe the depth to the sleeve. The sleeve does have a hole in the middle so if you're not paying attention you might be probing through the center. If the hole is deep enough to accommodate your new SS bolt and you don't want to remove this old junk, proceed with the new bolt installation. Otherwise continue with step 2.
  2. Continue hand drilling into the sleeve. You will make progress. 
     • If you feel like you're stalling out, switch to the 2-cutter bit and try to hammer a while without turning the bit. I think this was helping.
     • Use the blow tube liberally, get all of that crap out of there.
  3. Once you are seeing just rock dust coming out of the hole when blow tubing, you can be confident you've removed all of the sleeve.
  4. Drill to correct depth, install new bolt, etc.

Useful tips

• Use brand new bits. I found that after just a couple sleeve removals my 3/8" ti nitride bit was done and refused to catch on the sleeve. It was just spinning round and round no matter what I did. I swapped it for a new one and boom it drilled right into that sleeve like it was butter.
• Wear PPE. There will be sharp metal shavings everywhere. Eye pro is a good idea and gloves are a must.
• Do not ever use these bolts again... they're a pain in the ass to remove and you can't tighten them to spec without special tools. They are supposed to be tightened to 40 ft-lbs... a normal person can't turn even a long wrench to more than 25 ft-lbs.

Outstanding question

• Are there better metal-cutting bits I should be using than these titanium nitride coated ones? Seriously this bit was NOT cutting after removing ~4 sleeves. Is there something else I could use that would remain sharp longer?
• The metal-cutting bits I was using have a cutting angle of 135°, do you think using bits with 118° cutting angle would be better?

Thanks all for your time, best of luck out there. I will post updates when I go out to perform the rebolting.

Basically as soon as I posted that I had a better idea - tap and pull.

This is easier, required fewer tools, tools are lighter, and seemed to work no problem at all. I only did it once but it was easy peasy.

1. Unscrew stud as before
2. Using some kind of drill bit holding apparatus (still figuring this out) and 5/16" ti nitride metal-cutting bit, drill through the center of the sleeve. I did it by hand just gripping a detached chuck holding the bit.
3. Using 3/8" spiral flute tap, tap the sleeve
4. Screw in threaded rod and extract with Hurley jr

I will experiment with this further. I with there was such a thing as a drill bit with a square end so I could use my tap wrench with the 5/16" bit. Any thoughts? Maybe I can skip it and go straight to the spiral flute tap? I have two more bolts to test on, we'll see.

The easiest thing to try first is screw the eyebolt back in finger tight and funk it straight out. Maybe be gentle at first to get the sleeve unstuck without just ripping through the threads.

matt hoffman wrote:

 I with there was such a thing as a drill bit with a square end so I could use my tap wrench with the 5/16" bit. Any thoughts? Maybe I can skip it and go straight to the spiral flute tap? I have two more bolts to test on, we'll see.

Skipping the tap may work, especially if the metal is soft enough to drill by hand. If you like the method you used, it would be pretty easy to use an angle grinder to make flats on the bit to fit the tap wrench. Some tap wrenches will also grab a round shank

my first thought was funking it out like the previous comment.