Best Practices for Bolt Removal

by Jason Haas

The importance of re-using the same hole
Removing wedge bolts
Removing sleeve bolts
Removing button heads and star drives
Removing other miscellaneous bolts

The importance to re-using the same hole

The cliffs on which we climb are not renewable and the holes we drill are not self-healing. Each hole is permanent and has consequences. By re-using bolt holes, we can minimize our impact, both to the rock and to the climbing experience.

Climbers who have visited the limestone cliffs of Thailand—where salty ocean water speeds corrosion—may have experienced these impacts. In Thailand, it is not uncommon to climb up to a bolt and have to decide which of three, or even four, bolts to clip, often choosing among the original sleeve bolt and two or three types of glue-ins. Even on routes where the sleeve bolt has been removed and the glue-ins have been chopped, the triangle of remaining metal can still be highly visible.

The same problem exists at some areas in the United States. Not only does this create a visual eyesore, but eventually, bolters will run out of real estate for placing a new bolt. Sometimes there is just one clipping hold, which limits how far away the bolt can be placed.

Re-using the original bolt hole enhances the climbing experience for others by not having scraps of metal sticking out, and it preserves the nature of the first ascent. Plus, it can be done for generations to come, making sure climbers of the future get to climb the route the way it was intended.

In order to do that, the old bolt has to be fully removed. Oftentimes a new, enlarged hole is drilled through the old bolt hole, and a larger, beefier bolt is placed in the exact same location. This sustainable practice is an art, and we encourage re-bolters to hone their craft, striving to reuse 100 percent of the old boltholes, unless the original bolt location is a safety concern.

What follows is a guide for how to remove the wide variety of bolts you’ll likely encounter that need to be replaced. No matter the bolt type, however, remember that once you begin pulling a bolt, don’t stop until the bolt is either out or has sheared off. Leaving a partly pulled bolt could create a deadly situation for the next climber. It’s also critical to put a new bolt back in its place. So, if you’re about to run out of daylight, or you’re not sure if you can finish the job for any reason, don’t start.

How to patch an old bolt hole

Occasionally—if the original bolt was placed in fractured or hollow rock, for example—it may be necessary to drill a new hole. In these cases, be sure to patch the old hole. The best method for doing that is to make sure there is no metal sticking out of the rock. If the old bolt is a wedge bolt, make sure the threads are snapped off inside the hole if you didn’t fully remove it. With sleeve bolts, extract the bolt and be sure to tap the sleeve into the hole with a metal punch if you’re not going to fully remove it.

Then use an epoxy to fill in the hole and sprinkle some rock dust on the surface to help camouflage the patch job. We recommend an epoxy putty used by the ASCA, which comes in multiple shades to match rock types. Simply rip off a piece, roll and smash the two parts together until the colors blend into one uniform color. Then press it into the hole and smooth it out. The putty is harder to use when it’s cold out, so keep it in your jacket when the weather is chilly.

Removing wedge bolts

What were once thought to be the most difficult bolts to remove have become some of the easiest with the proper tools. Wedge bolts are perhaps the most prevalent bolt type in the United States because of how inexpensive the plated-steel versions are as well as how simple they are to place. Wedge bolts have a tapered end with an expansion clip on it and a threaded head with a nut on the front. The most common size is 3/8 inch in diameter.

Tools you'll need

  • A 6- to 8-inch long adjustable crescent wrench or fixed 1/2-inch and 9/16-inch ratchet wrenches
  • Spinner tool: A standard 3/8-inch coupler nut from any hardware store with one side is drilled to 1/2 inch so it can be attached to an SDS adapter tool. Put a setscrew in the side of the coupler nut that has not been bored out to keep the drill from going too deep and grinding against the rock rather than spinning the bolt.
  • Hammer drill
  • Hammer
  • Greenlee punch driver or homemade equivalent: The tool costs several hundred dollars, but you can buy them used or get the Chinese knockoff, which climbers have been using for a few years now without problems. Or it may make sense for a LCO to buy one that can be lent out to people working on re-bolting projects. Also, Greg German has built a tool that works very much the same but only costs around $25 to make. Watch this video to learn how to make one yourself:


    Climbtech is also making them and willing be selling them for cost; check out their website for more info.
  • Adapter tool to attach Greenlee to wedge bolt: This homemade tool has one side that threads into the Greenlee and one side that screws on the 3/8-inch wedge bolt.
  • Spacers for Greenlee: The tool comes with a heavy metal spacer. A nice alternative are these plastic ones. Search the webpage for part number 94639A229, and then choose the 3/4-inch size. (So it's a 1.5-inch OD Nylon spacer, 3/4-inch length, and 3/4-inch screw size.) The advantage of these spacers is that you can use a saw to cut a notch into them so you don’t have to fully remove the whole unit in order add another spacer. They’re also lighter and cheaper than the metal ones.
  • Hacksaw blade: Harbor Freight sells a cheap two-pack for $2. Put a key ring on each end so you can use your fingers to pull it back and forth.
  • Water

Step 1: Unscrew the bolt’s nut with a crescent wrench and remove the hanger.

Step 2: Attach your spinner tool to your hammer drill. Screw it onto the stud of the wedge bolt.

Step 3: With your drill in hammer mode, briefly spin the bolt, pushing it deeper into the hole to disengage the collar. This should only take a burst or two from the trigger.

Note: While you could tap the stud back into the hole with a hammer to disengage the collar, you risk hammering the bolt in too deeply and, thus, not having enough exposed threads to attach the spinner tool.

Step 4: Change your drill from hammer mode to rotary mode. Pull the trigger and spin the bolt in short bursts. Without applying a lot of force, push and pull the bolt a bit while spinning it. The goal is to grind rock dust into the collar and wear it down a bit. Keep in mind this generates an incredible amount of heat. Because of that, you’ll need to add water. You can use a spray bottle or just spit some water into the hole. If steam comes out or you hear the water sizzling, it’s too hot. Add water and wait another 20 seconds or you’ll risk heating the bolt up too much and breaking it off inside the hole.

Essentially what’s happening in this step is you’re spinning the bolt while the collar stays put. The goal is to score a small groove the collar catches on so that it can no longer fully engage and wedge inside the bolt hole. Be careful not to spin for too long or, again, you can break the bolt.

You may be able to completely spin the bolt out of the hole and not use the Greenlee tool (see Step 6) at all (quite common in sandstone and limestone). This is a slow-and-steady finesse technique, not a brute-force operation. If you have a Greenlee and it doesn’t look like the bolt will just spin out, stop when the bolt becomes quite loose in the hole. If the bolt locks up on you and won’t spin, put the drill back in hammer mode and push the bolt deeper into the hole to disengage the collar again.

Step 5: Put the drill in reverse, pull the trigger, and unscrew the spinner tool from the bolt.

Step 6: Attach the Greenlee (or homemade equivalent) by screwing the adapter into the Greenlee and then screwing the whole unit onto the wedge bolt. You really only need about three threads worth of contact for the tool to work (but more is fine).

Step 7: Pump the Greenlee. You’ll feel the bolt slide forward. The trick is to not force it. If pumping becomes too difficult, that’s a sign the bolt could snap off. Consider removing the Greenlee and spinning the bolt some more. If the Greenlee suddenly becomes impossible to pump, you’ve reached the tool’s maximum one inch of travel and it’s time to release the pressure on the Greenlee and add another spacer before pumping more. You can blow an O-ring seal by trying to force it, so try to be aware of when that travel is up. The whole bolt should slide right out. Once you get the hang of it, the only bolts that come out faster are button heads.

Note: If the initial threads are too damaged to remove the nut and thread the spinner tool on, all is not lost. As long as there are enough undamaged threads still sticking out of the rock—roughly three or more—you can use a hacksaw blade to lop off the damaged portion. You can attach key rings to either end of a cheap hacksaw blade meant for cutting through metal to give you something to hold on to. Slide the blade back and forth until you cut through the bolt and have a fresh thread to start from.

Removing sleeve bolts

Sleeve bolts used for rock climbing typically come in two diameters: 3/8 inch and1/2 inch. Lengths can also vary. Regardless of the old bolt’s diameter, the removal process is the same—you’ll just need different-sized bits for each.

Tools you'll need

  • A 6- to 8-inch long adjustable crescent wrench or fixed 1/2-inch and 9/16-inch ratchet wrenches
  • Hook tool: The hook tool can be made by lopping off one end of an L-shaped Allen wrench and then filing the tip into a pointed hook
  • Tap and die (3/8-inch tap for 3/8-inch bolts, 7/16-inch tap for 1/2-inch bolts). Do not buy a standard tap, as they are too brittle. Instead, buy a spiral flute bottoming tap, which are a bit more expensive but self-cleaning and more durable.
  • Magnet
  • Funkness device: A swaged cable that attaches to the bolt on one end and to your hammer on the other. A funkness can be made at home or purchased online with some searching. It should be a little shorter than your arm so it comes taut before your arm fully straightens. You can attach the funkness to the bolt using a locking carabiner, but the carabiner will become trashed quickly. A better alternative is to use heavy-duty shackles from a hardware store.
  • Hammer with eyelet: The eyelet is necessary for attaching the funkness device. The Black Diamond Yosemite Hammer is the go-to for this purpose among developers.
  • Greenlee punch driver or homemade equivalent : The tool costs several hundred dollars, but you can buy them used or get the Chinese knockoff, which climbers have been using for a few years now without problems. Or it may make sense for a LCO to buy one that can be lent out to people working on re-bolting projects. Also, Greg German has built a tool that works very much the same but only costs around $25 to make. Watch this video to learn how to make one yourself:
    Climbtech is also making them and willing to sell them for cost; check out their website for more info.
  • Spacers for Greenlee: The tool comes with a heavy metal spacer. A nice alternative are these plastic ones. Search the webpage for part number 94639A229, and then choose the 3/4-inch size. (So it's a 1.5-inch OD Nylon spacer, 3/4-inch length, and 3/4-inch screw size.) The advantage of these spacers is that you can use a saw to cut a notch into them so you don’t have to fully remove the whole unit in order add another spacer. They’re also lighter and cheaper than the metal ones.
  • Draw stud for Greenlee

Step 1: Loosen the bolt with a crescent wrench and unscrew it by about a 1/2-inch.

Step 2: Using a hammer, tap the bolt back into the hole. The goal is to push the cone down and out of the sleeve it is wedged in.

Step 3: Completely unscrew the bolt, pull it out and remove the hanger. When you pull the bolt out, try and pull it out at a bit of an angle to attempt to catch the blue plastic bushing and upper metal sleeve (only present in longer bolts).

Step 4: Use a hook tool to try and fish out the last sleeve. The best bet is to catch the edge of the hook in the upside-down triangle cutout in the sleeve. If you’re successful, move to Step 8. If unsuccessful, see Step 5.

Step 5: If the sleeves do not come out easily, you’ll need to use a tap. For 3/8-inch bolts, use a 3/8-inch tap. For 1/2-inch bolts, use a 7/16-inch tap. Taps are easy to break so be careful; this is about finesse, not strength. Screw the tap into the sleeve about a quarter to half a turn, and then back it out a full half turn. This will allow the spiraling curl of metal you’re cutting to be removed from the hole. Keep repeating this process until you have at least three solid threads cut into the sleeve but preferably closer to six.

Step 6: Unscrew the tap and insert a magnet into the hole to try and fish out any remaining metal shavings.

Step 7: Once you have cut the threads, you have several options for removing the sleeve. Option A: Screw in the original bolt with hanger on it and “funk” (yank using the funkness device) the sleeve out. Option B: Screw in a draw stud with an eyebolt on the other end and funk the sleeve out. The advantage to this method is that the eyebolt allows you to pull directly out on the bolt compared to using the hanger, which causes you to pull at more of an angle. Option C: Screw one end of the draw stud into the sleeve and the other end into the Greenlee. Pump the Greenlee to pull the sleeve forward but don’t force it. If the Greenlee suddenly becomes impossible to pump, you’ve reached the tool’s maximum one inch of travel and it’s time to release the pressure on the Greenlee and add another spacer before pumping more.

Step 8: Remove the cone. The cone has threads on it, so the three options listed in Step 7 can also be used to extract the cone. However, trying to funk the cone out can cause the cone to turn sideways and become stuck, a problem that you won’t have with the Greenlee. If the cone does get stuck, you can use a special bit like the one to drill through the cone. Use only very light pressure and be ready to back off as soon as it binds. Use a magnet to fish out pieces every 20 seconds of drilling.

Note: You cannot use the drill-through techniques for a sleeve that is stuck in the hole. The sleeves crumple toward the middle and either jam up the bit or spin with it, impeding the cutting action.

Removing button heads and star drives

Star drives and 1/4-inch button heads have a lot of differences, but the process for removing both of these types of compression bolts is quite similar. The process for removing the more uncommon, but also more bomber, 5/16-inch button head is also similar, but they are physically harder to extract and will require additional effort and techniques. The added 1/16 inch of diameter makes a world of difference and can stretch the time it takes to remove the bolt from just a couple of seconds to half an hour. (See tips for removing 5/16-inch button heads at the end of this section.)

The standard method for removing 1/4-inch button heads and star drives involves using a “tuning fork” and can create a small degree of scarring, which is typically hidden under the new bolt hanger. Still, some people try to avoid this damage by trying to “funk” these bolts out before trying a tuning fork. While this can work, there is a serious risk of breaking the bolt inside the hole (and the hanger if it’s paired with a Leeper hanger).

Tools you'll need

  • Thin “starter” piton
  • Tuning fork: A Black Diamond #3 Lost Arrow piton that has had the center milled out professionally. The ASCA has been kind enough to give these to folks in the past and is a good place to start if you need one. If you don’t have one and can’t mill one yourself, you can use a crowbar instead. The advantage of a tuning fork over the crowbar is that the taper is longer and the groove is meant for the width of a ¼-inch bolt.
  • Funkness device: A swaged cable that attaches to the bolt on one end and to your hammer on the other. A funkness can be made at home or purchased online with some searching. It should be a little shorter than your arm so it comes taut before your arm fully straightens. You can attach the funkness to the bolt using a locking carabiner, but the carabiner will become trashed quickly. A better alternative is to use heavy-duty shackles from a hardware store.
  • Hammer with eyelet: The eyelet is necessary for attaching a funkness device. The Black Diamond Yosemite Hammer is the go-to for this purpose among developers.

Extra tools for removing star drives:

  • Old drill bit to drill through the sleeve
  • Hammer drill
  • Needle-nose pliers

Extra tools for removing 5/16-inch button heads:

  • Extra pins for stacking
  • Crowbar
  • Heavier hammer

Step 1: Whack a thin piton under the hanger to “pop” the bolt head up a little bit. If removing star drives, you can typically do this between the bolt and the hanger rather than between the hanger and the rock. If the compression bolt is a threaded version (instead of the button head version) be sure to tighten the nut down before starting. This ensures the nut won’t come loose, leaving you without a way to get the bolt out.

Step 2: Insert a tuning fork under the hanger. Pick a spot that seems like the easiest place to slide the tuning fork under. Sometimes it’s easiest to start directly under the hanger where a carabiner would be clipped, but not always. Tap the tuning fork under the hanger so that it forms a wedge and begins to force the bolt from its hole. If you seem to get stuck, hit the tuning fork back out and try another spot. It often works well to try the opposite side.

Step 3: If you hit the tuning fork in all the way to the hilt and the compression

bolt still hasn’t popped out, you have two options. The safest bet is to stack another tuning fork or piton under the first tuning fork to make a fatter wedge. The other option is to “funk” (yank the bolt using your funkness device) the bolt out, which can risk breaking the bolt itself. Trying to funk the bolt out can also break the hanger while the bolt is still in the wall. Additionally, funking is hard on the body, especially the elbow and shoulder, and it’s best to wear safety glasses and look away from the bolt if you do try to funk it out.

Step 4: When a button head comes out, you have an empty hole that’s ready to be bored wider and deeper for a new stainless steel bolt. If the bolt you just removed is a star drive, you will still have the sleeve to pull out. The sleeve is soft lead and quite malleable, which can make it a pain to extract. You can try and fish it out with needle-nose pliers, use a tap to remove it (see section on removing sleeve bolts, though you’ll require a smaller tap) or drill through the sleeve.

To try drilling, start by using a dull bit or a bit like this works well. If drilling through the sleeve, start off slowly because the drill will want to skip. Drill in a little ways, then back the drill out to help the old metal come out of the hole rather than pack into the back of it. If the sleeve does get packed into the back of the hole, you’ll get some resistance, which is difficult but not impossible to drill through.

Once through the sleeve, you can continue drilling to the required depth for your new bolt, but be sure to switch to your newer, sharper bit so you bore a better hole.

Note: If the head of the bolt breaks before you remove the bolt, all is not necessarily lost. You could drill a small hole next to the bolt with a 7/64-inch masonry bit and then tap the bolt back and forth until it comes out. This shouldn’t impact the 1/2-inch hole you need to drill for the new bolt.

Additional tips for removing 5/16-inch button heads:

These bolts are stubborn. One technique is to just stack more pins and keep whacking away at them. Or you can try the more brutish approach of enlisting the help of a crowbar. Once you get the head up enough to slide a crowbar under, you can start trying to pry the bolt out.

It’s possible to break your crowbar trying to employ this technique. Do not bounce on the crowbar as you’ll likely end up breaking the bolt if not the crowbar itself. Instead, apply steady pressure, which you can do by planting your feet on the wall and pulling out with the crowbar. In the end, you’ll probably use a variety of methods, switching back and forth between stacking pins and using a crowbar.

Removing other miscellaneous bolts

Mammut ring bolts

These guys are a real pain to get out. When placed correctly, they are really secure, but when placed incorrectly, you can funk them right out of the wall with little effort. The techniques for removing a well-placed ring bolt—one that bottoms out at the back of the hole—is still being refined.

The method that has shown the most promise is through the center of the bolt to disengage the cone, although this can be difficult to do without making a jig first as you have to be sure to keep the drill straight in both the x and y axis to avoid breaking the bit. Another technique I’ve used successfully is drilling really tiny holes around the bolt itself using a 3/32-inch or 7/64-inch bit. The bolt is only in the rock about 1.5 inches, so I don’t drill very deep. Once I’ve gone all the way around the bolt, I funk it out.

This leaves a wider hole than you can use for a 1/2-inch bolt, so they have to be replaced with a larger diameter glue-in. There may be a better way that climbers haven’t yet figured out, so if you come up with a method, let us know.

Petzl Long Lifes

Most re-bolters will tell you that if it’s placed in bomber granite, a Petzl Long Life bolt can be left alone, as it’s stainless steel and probably just fine in terms of climbing safety. But in medium to soft rock, they need to come out, which can be easier said than done.

In limestone, they have been popped out the same way a compression bolt is pulled: Hammer a thin piton under the bolt/hanger and then use a combination of stacking pins and crowbars to pull the bolt out.

If you do need to remove a Long Life from really hard rock, you’ll probably want to avoid trying to drill out the pin. This technique has worked, but it will blow through your drill’s battery life and your cobalt steel bits. A better, but not necessarily easier, strategy is to use a hydraulic puller. This works about half the time. When it doesn’t and the hanger breaks, angle grind off the bolt and then core out the remaining piece in the rock with a diamond core drill. You’ll end up having a hole roughly 14 mm in diameter. To reuse the same hole, you’ll have to place a 14- or 16-mm glue-in.

Self-drill bolts (aka drop-ins)

To remove a self-drill bolt, keep the machine bolt in the sleeve and try to remove it the same way you would a compression bolt (such as a button head) by using a tuning fork, stacking pins and a crowbar. The whole unit can come out with this method, but if it doesn’t, use a fat Lost Arrow or equivalent to tap all around the collar. Once the sleeve loosens up and comes out, the steel cone will still be in the back of the hole. These can sometimes be fished out with needle-nose pliers or a strong magnet. If that doesn’t work, try drilling through it with a special bit designed for going through metal, like this. If that too doesn’t work, you’ll have to patch the hole. If you do get it out, most self-drive bolts are in 12 mm holes (roughly .47 inches), and you can expand the hole to a 1/2-inch and place a five-piece sleeve bolt or glue-in.

If the self-drive sleeve (usually 8 mm in diameter) doesn’t come out easily, you could use a tap to pull it, or try the following method: Get a few 1/4-inch ball bearings; a high-quality, hardened steel 8 mm machine bolt; a wrench; and some penetrating oil. Remove the hanger and bolt from the sleeve with a wrench. Insert a small amount of penetrating oil and leave it for a period of time to let any bond between the sleeve and the cone loosen. Next, insert one or two ball bearing into the back of the sleeve, and screw in the 8 mm machine bolt until it makes contact with the ball bearings. Apply clockwise force to the machine bolt, putting pressure on the bearings, which then put pressure on the cone. As the bolt turns clockwise, the threads force the sleeve out of the hole. If the head of the bolt reaches the sleeve before the sleeve is freed from the hole, insert another ball bearing. Once free, remove the sleeve and cone. You’ll be left with 12 mm by 30 mm hole. This procedure is most effective in softer rock and when rust has not acted to bond the cone to the sleeve. Stubborn sleeves can cause the threads on the machine bolt to strip before they will release.

Torque bolts

You can simply unscrew torque bolts, but the lead cone will still be in the hole. You can try and fish it out with needle-nose pliers, though that usually doesn’t work. You can also try drilling through the cone with a special bit meant for going through metal, such as this one from Dewalt. If that doesn’t work, you’ll have to patch the hole.

Zamac Nailins

Use the standard tuning fork method for removing button heads. They usually pop right out, but a crowbar can be employed if necessary. They typically leave a clean hole when removed.

Drilled angles

The school of thought for a long time was that the best way to bolt soft rock, especially in the desert, was not actually with a bolt but with a piton. The idea was you drilled a hole (typically 3/8 or 1/2 inch) and hammered an angle piton into the hole. But soft rock erodes over the years, allowing the pitons to loosen. Some of these fixed pins fall out on their own and others can be removed using just your fingers or with the light tug of a funkness device. The remaining holes tend to be a bit conical due to the erosion and, therefore, hard to re-use with a mechanical bolt. But if the rock is that soft, glue-ins are the way to go anyway.

Machine-bolt rivet

Begin by trying to unscrew it with a crescent wrench. If that doesn’t work, use a crowbar. If that too doesn’t work, go to Plan C: Hammer the bolt side to side until it breaks and then use a punch tool to drive the remaining shards back into the rock and patch the hole.

Aluminum Dowel

Try simply pulling it out. They can come out using just your fingers, but a pair of vice grips will give better pulling power. Typically, though, you’ll have to break it off. But because they’re made of soft aluminum, you can just drill through the piece still stuck in the rock to create the new bolt hole.

Glue-ins

These shouldn’t have to be removed, at least not yet. Two scenarios in which they still might need to come out could be if someone has intentionally damaged them, maybe hammering the eyelet flat against the rock, or if a stainless steel glue-in was used at an oceanside crag where a titanium glue-in needs to be used instead. Because of their round edge on certain types of glue-ins, there’s also a risk of climbers lowering directly through-them, wearing them down to the point of needing replacement. This practice should be strictly discouraged.

Whatever the case, if the glue-in needs to come out, you’ve probably got your work cut out for you. This is a bit of terra incognita as most developers and re-bolters have not tried to deal with this issue too much. A few of the older glue-ins were simply straight-shafted rods. At least one individual, Morgan Patterson in Connecticut, has successfully pulled/twisted them out after using a blow torch to heat the glue. It is reported to be extremely difficult. The dangers of using a blow torch while hanging from a rope should also be apparent. It’s also not clear how effective this method is or if you could even re-use the same hole when you were done.

However, more modern glue-in bolts, such as the ClimbTech Wave Bolt, that are secured with modern epoxy glues and are not simply straight-shafted rods are believed to be virtually impossible to remove. Currently, the best advice is to use an angle grinder or Dremel tool and cut the bolt off flush to the rock wall. After, you could potentially core drill the hole to make a larger hole and place an even larger glue-in its place. This works in theory but would be a massive undertaking given the diameter of the glue-in hole that is already there in addition to the length of the bolt itself.

If you have to deal with this situation and you come up with viable solution, let us know as many re-bolters are curious how future generations will deal with this issue. While glue-ins are not fully removable and as such are not considered a sustainable, re-usable bolt option, testing from several manufacturers have suggested a modern, stainless steel glue-in has a working life of 200-500 years outside of a marine environment. If that’s true, the idea of needing to someday replace them seems like a moot point.

While most of the data on these bolts are coming out of laboratory tests, the Emhart Molly Company did some real-world testing on 20-year-old glue-in bolts placed in an outdoor environment where they experienced constant, dynamic stressing. Their results showed that “in fact, the average strength of the anchors tested [actually] increased with age” (Climbing #115). Imagine that!