If you are to rock climbing, this article will help you identify, plan for, and mitigate the hazards caused by sketchy bolts. When we encounter a bolt, we have no idea whether it’s good, bad, or just ugly. The reality is, bolts can fail due to metal fatigue, oxidation, improper placement, or hidden internal processes like stress corrosion cracking (SCC), in which tiny fissures form in the metal due to chemical reactions. While the design and construction of modern bolts make this a rarity on, say, routes from the past decade, older bolts with smaller diameters can fail. Identifying these bolts can help you assess the risk in clipping and making that next move. I’ve been rebolting for 30 years, and have replaced almost 1,000 bolts. Some old bolts looked great, while others have broken with a fl ick of the rope. Knowing the difference can save your life.
Bad Bolts
A bolt can be bad either because the rock is bad, the bolt is bad, or if it really isn’t your day, both are bad. To a large degree, the compressive strength—the force that the rock can withstand before breaking—varies by rock type. Granite tends to be the strongest, holding between 4,000 and 40,000 pounds. Good sandstone ranges from 1,000 to 20,000 pounds. And limestone typically holds between 1,000 and 5,000 pounds. In general, be cautious when the rock around the hole has broken away, exposing the bolt. If the stone is fractured, there are spider-web cracks leading from the bolt hole, or if the surrounding rock is hollow (tap it with a knuckle or carabiner to see if it reverberates), the strength can be compromised.
At times, the nut or head of the bolt that holds the hanger to the rock can be loose, causing a “spinner.” In this case, finger-tighten the nut or bolt, which will make the bolt adequate for the moment. Carrying a small, adjustable wrench helps in these circumstances—only tighten until it becomes significantly more difficult to turn the wrench past a logical “yield point,” lest the metal fatigue or snap. If the bolt sticks out of the rock and cannot be tightened, place a wired stopper between the hanger and the rock to reduce advantage and increase strength. Clip the wire, not the hanger, and climb carefully, as falling on it may be dangerous. As with any suspect bolt, using a load-limiting device such as a Screamer might help. If there is a traditional gear placement available as a backup, put in some extra gear.
Bad Hangers
In some circumstances, the bolt is good but the hanger is bad. The first step in judging a hanger’s trustworthiness is identifying the manufacturer. Many hangers produced before the mid-1980s can be suspect. There are two in particular to beware: Leeper hangers and SMC hangers. Unfortunately, the manufacturer of the Leeper hanger, of which 95,000 were produced from 1962 to 1984, noted their potential failure due to their susceptibility to SCC. Meanwhile, the slim-profile SMC chromoly hangers from the 1970s were prone to cracking and then breaking under load, resulting in climber deaths: These had a horizontal logo. In the 1980s, SMC beefed up their design with a stainless-steel version, which has a vertically oriented logo.
If you see an SMC logo, think, “Sideways is bad, but up is good.” In addition, homemade hangers, even though they may contain a lot of metal, have unknown manufacturing processes. These hangers should be treated as suspect; replacement is mandatory. Mixing metals—i.e., pairing a stainless-steel bolt with a zinc-plated hanger and vice versa—can accelerate deterioration. (Stainless has a dull, gunmetal grey color, while plated is bright silver or almost blue.) Always use like metals, with a preference toward stainless steel, which lasts longer than plated steel. Ideally, the bolt-and-hanger combo will be both stainless and use modern hardware from Petzl, Fixe, Metolius, Climb Tech, and other reputable manufacturers.
Bolting Breakdown
American climbers first started using bolts in the 1930s. Since then, our technology has evolved, but many original bolts are still in place. The sidebar at right provides a guide, from worst to best. Rebolting Efforts Through the eff orts of the UIAA and the Access Fund, there have been big advancements in developing best practices. National rebolting initiatives include the American Safe Climbing Association, and the American Alpine Club and Access Fund’s Anchor Replacement Fund. These organizations and a small group of dedicated rebolters have greatly increased the use of safer, long-lasting hardware. Many climbing areas and climbing websites also have systems in place for reporting suspect bolts and hangers. Take the time to report any such bolts you encounter to your local climber organization on Mountain Project—it is a critical community service.
Bad Bolts
A bolt can be bad either because the rock is bad, the bolt is bad, or if it really isn’t your day, both are bad. To a large degree, the compressive strength—the force that the rock can withstand before breaking—varies by rock type. Granite tends to be the strongest, holding between 4,000 and 40,000 pounds. Good sandstone ranges from 1,000 to 20,000 pounds. And limestone typically holds between 1,000 and 5,000 pounds. In general, be cautious when the rock around the hole has broken away, exposing the bolt. If the stone is fractured, there are spider-web cracks leading from the bolt hole, or if the surrounding rock is hollow (tap it with a knuckle or carabiner to see if it reverberates), the strength can be compromised.
At times, the nut or head of the bolt that holds the hanger to the rock can be loose, causing a “spinner.” In this case, finger-tighten the nut or bolt, which will make the bolt adequate for the moment. Carrying a small, adjustable wrench helps in these circumstances—only tighten until it becomes significantly more difficult to turn the wrench past a logical “yield point,” lest the metal fatigue or snap. If the bolt sticks out of the rock and cannot be tightened, place a wired stopper between the hanger and the rock to reduce advantage and increase strength. Clip the wire, not the hanger, and climb carefully, as falling on it may be dangerous. As with any suspect bolt, using a load-limiting device such as a Screamer might help. If there is a traditional gear placement available as a backup, put in some extra gear.
Bad Hangers
In some circumstances, the bolt is good but the hanger is bad. The first step in judging a hanger’s trustworthiness is identifying the manufacturer. Many hangers produced before the mid-1980s can be suspect. There are two in particular to beware: Leeper hangers and SMC hangers. Unfortunately, the manufacturer of the Leeper hanger, of which 95,000 were produced from 1962 to 1984, noted their potential failure due to their susceptibility to SCC. Meanwhile, the slim-profile SMC chromoly hangers from the 1970s were prone to cracking and then breaking under load, resulting in climber deaths: These had a horizontal logo. In the 1980s, SMC beefed up their design with a stainless-steel version, which has a vertically oriented logo.
If you see an SMC logo, think, “Sideways is bad, but up is good.” In addition, homemade hangers, even though they may contain a lot of metal, have unknown manufacturing processes. These hangers should be treated as suspect; replacement is mandatory. Mixing metals—i.e., pairing a stainless-steel bolt with a zinc-plated hanger and vice versa—can accelerate deterioration. (Stainless has a dull, gunmetal grey color, while plated is bright silver or almost blue.) Always use like metals, with a preference toward stainless steel, which lasts longer than plated steel. Ideally, the bolt-and-hanger combo will be both stainless and use modern hardware from Petzl, Fixe, Metolius, Climb Tech, and other reputable manufacturers.
Bolting Breakdown
American climbers first started using bolts in the 1930s. Since then, our technology has evolved, but many original bolts are still in place. The sidebar at right provides a guide, from worst to best. Rebolting Efforts Through the eff orts of the UIAA and the Access Fund, there have been big advancements in developing best practices. National rebolting initiatives include the American Safe Climbing Association, and the American Alpine Club and Access Fund’s Anchor Replacement Fund. These organizations and a small group of dedicated rebolters have greatly increased the use of safer, long-lasting hardware. Many climbing areas and climbing websites also have systems in place for reporting suspect bolts and hangers. Take the time to report any such bolts you encounter to your local climber organization on Mountain Project—it is a critical community service.