At what angle should an ice screw be screwed into the ice?

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Recently we were climbing up a glacier with the ice at an angle of around 80°. We were placing the ice screws angling slightly upwards with respect to the slope of the ice wall.



However, one from our team, who stays in Norway said that the screws should always be angled downwards such that the weight is taken completely by the threads of the screw and not by the ice patch surrounding the ice screw. Apparently, this is how he was taught by a guide while climbing up a frozen waterfall.



For us, it felt natural to angle up the ice screws so that in case of a fall, the screw held on to the ice (similar to angling the pegs of a tent away from the tent). The claim that the weight of a fall should be taken completely by the ice screw and its threads seems a bit risky to me.



So is the claim correct? What's the general practice? Does the practice vary for a waterfall climb (as damaging the ice there could potentially lead to a whole slab of the waterfall falling off?)?










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  • Are you talking about ice screws or pitons? Those are completely different things. A correct answer to your question depends on the exact type of protective gear used.
    – Guran
    30 mins ago










  • @Guran Edited. I'm referring to screws. Most use the term ice pitons and ice screws interchangeably.
    – Ricketyship
    17 mins ago










  • Ok. Though they do not see much use today, there are also hammer-in ice "screws" (i.e "warthogs"), more resembling pitons. You probably want to angle those upwards.
    – Guran
    2 mins ago














up vote
4
down vote

favorite












Recently we were climbing up a glacier with the ice at an angle of around 80°. We were placing the ice screws angling slightly upwards with respect to the slope of the ice wall.



However, one from our team, who stays in Norway said that the screws should always be angled downwards such that the weight is taken completely by the threads of the screw and not by the ice patch surrounding the ice screw. Apparently, this is how he was taught by a guide while climbing up a frozen waterfall.



For us, it felt natural to angle up the ice screws so that in case of a fall, the screw held on to the ice (similar to angling the pegs of a tent away from the tent). The claim that the weight of a fall should be taken completely by the ice screw and its threads seems a bit risky to me.



So is the claim correct? What's the general practice? Does the practice vary for a waterfall climb (as damaging the ice there could potentially lead to a whole slab of the waterfall falling off?)?










share|improve this question























  • Are you talking about ice screws or pitons? Those are completely different things. A correct answer to your question depends on the exact type of protective gear used.
    – Guran
    30 mins ago










  • @Guran Edited. I'm referring to screws. Most use the term ice pitons and ice screws interchangeably.
    – Ricketyship
    17 mins ago










  • Ok. Though they do not see much use today, there are also hammer-in ice "screws" (i.e "warthogs"), more resembling pitons. You probably want to angle those upwards.
    – Guran
    2 mins ago












up vote
4
down vote

favorite









up vote
4
down vote

favorite











Recently we were climbing up a glacier with the ice at an angle of around 80°. We were placing the ice screws angling slightly upwards with respect to the slope of the ice wall.



However, one from our team, who stays in Norway said that the screws should always be angled downwards such that the weight is taken completely by the threads of the screw and not by the ice patch surrounding the ice screw. Apparently, this is how he was taught by a guide while climbing up a frozen waterfall.



For us, it felt natural to angle up the ice screws so that in case of a fall, the screw held on to the ice (similar to angling the pegs of a tent away from the tent). The claim that the weight of a fall should be taken completely by the ice screw and its threads seems a bit risky to me.



So is the claim correct? What's the general practice? Does the practice vary for a waterfall climb (as damaging the ice there could potentially lead to a whole slab of the waterfall falling off?)?










share|improve this question















Recently we were climbing up a glacier with the ice at an angle of around 80°. We were placing the ice screws angling slightly upwards with respect to the slope of the ice wall.



However, one from our team, who stays in Norway said that the screws should always be angled downwards such that the weight is taken completely by the threads of the screw and not by the ice patch surrounding the ice screw. Apparently, this is how he was taught by a guide while climbing up a frozen waterfall.



For us, it felt natural to angle up the ice screws so that in case of a fall, the screw held on to the ice (similar to angling the pegs of a tent away from the tent). The claim that the weight of a fall should be taken completely by the ice screw and its threads seems a bit risky to me.



So is the claim correct? What's the general practice? Does the practice vary for a waterfall climb (as damaging the ice there could potentially lead to a whole slab of the waterfall falling off?)?







safety gear climbing ice-climbing ice-screws






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edited 18 mins ago

























asked 1 hour ago









Ricketyship

5,60921757




5,60921757











  • Are you talking about ice screws or pitons? Those are completely different things. A correct answer to your question depends on the exact type of protective gear used.
    – Guran
    30 mins ago










  • @Guran Edited. I'm referring to screws. Most use the term ice pitons and ice screws interchangeably.
    – Ricketyship
    17 mins ago










  • Ok. Though they do not see much use today, there are also hammer-in ice "screws" (i.e "warthogs"), more resembling pitons. You probably want to angle those upwards.
    – Guran
    2 mins ago
















  • Are you talking about ice screws or pitons? Those are completely different things. A correct answer to your question depends on the exact type of protective gear used.
    – Guran
    30 mins ago










  • @Guran Edited. I'm referring to screws. Most use the term ice pitons and ice screws interchangeably.
    – Ricketyship
    17 mins ago










  • Ok. Though they do not see much use today, there are also hammer-in ice "screws" (i.e "warthogs"), more resembling pitons. You probably want to angle those upwards.
    – Guran
    2 mins ago















Are you talking about ice screws or pitons? Those are completely different things. A correct answer to your question depends on the exact type of protective gear used.
– Guran
30 mins ago




Are you talking about ice screws or pitons? Those are completely different things. A correct answer to your question depends on the exact type of protective gear used.
– Guran
30 mins ago












@Guran Edited. I'm referring to screws. Most use the term ice pitons and ice screws interchangeably.
– Ricketyship
17 mins ago




@Guran Edited. I'm referring to screws. Most use the term ice pitons and ice screws interchangeably.
– Ricketyship
17 mins ago












Ok. Though they do not see much use today, there are also hammer-in ice "screws" (i.e "warthogs"), more resembling pitons. You probably want to angle those upwards.
– Guran
2 mins ago




Ok. Though they do not see much use today, there are also hammer-in ice "screws" (i.e "warthogs"), more resembling pitons. You probably want to angle those upwards.
– Guran
2 mins ago










1 Answer
1






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up vote
4
down vote













All of the resources that I can find say that it should be done with the end pointing up and the hanger down with up to a twenty degree angle from vertical.




More surprising were Harmston's findings about screw angle. As it turns out, screws hold much better when they're angled in the direction of the falling force, as in the second scenario above. Perhaps needless to say, this is not intuitive. Much of the force is then resisted by the threads rather than the girth of the screw itself. This isn't a small difference either: an ice screw placed at a downward angle is as much as twice as strong as a screw placed at an upward "negative" angle.




Gear Physics: How Ice Screws Keep Ice Climbers from Falling to Their Deaths




Limited testing by Chris Harmston of Black Diamond and Craig Luebben about 10 years ago showed that ice screws with the hanger end angled down (negative angle) up to 20 degrees were stronger than screws with the hanger parallel to the ice or angled slightly up (positive angle). A negative angle does not, however, increase the strength of the threads; rather, it decreases the chance that the ice will blow out from under the screw.




Should I Angle Ice Screws Down?




Contrary to what you might think, the best angle for the screws is slightly upward, meaning the hanger is slightly lower than the teeth in the ice. This counterintuitive method is better because the holding power comes from the threads themselves and not from a “snow picket” effect, meaning you don’t get any mechanical advantage having the shaft of the screw levered against the ice (Fig. 2).




How to Build Bomber Ice Anchors




It was once thought necessary or beneficial for ice-screws to be place horizontally or with the hanger up for optimum hold. However, it has since been found experimentally that a screw place with the tip angled up often holds as well or better. This surprising result is thought to be due to the previously underestimated role of the threads in holding the screw in place. However, horizontal placements are usually recommended.




Wikipedia



So you would want to angle them up into the ice.






share|improve this answer




















  • Wow! That's something that's so counter-intuitive!
    – Ricketyship
    1 hour ago










  • Can we have some pictures? I'm confused with all the ups and downs :D
    – OddDeer
    1 hour ago










  • @Oddeer see the first source
    – Charlie Brumbaugh
    1 hour ago










  • This is a good answer, but perhaps you should add that the single most important factor for ice anchor strength is ice quality. Ensure that all threads engage in solid ice and that the screw is driven all the way in.
    – Guran
    26 mins ago










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1 Answer
1






active

oldest

votes








1 Answer
1






active

oldest

votes









active

oldest

votes






active

oldest

votes








up vote
4
down vote













All of the resources that I can find say that it should be done with the end pointing up and the hanger down with up to a twenty degree angle from vertical.




More surprising were Harmston's findings about screw angle. As it turns out, screws hold much better when they're angled in the direction of the falling force, as in the second scenario above. Perhaps needless to say, this is not intuitive. Much of the force is then resisted by the threads rather than the girth of the screw itself. This isn't a small difference either: an ice screw placed at a downward angle is as much as twice as strong as a screw placed at an upward "negative" angle.




Gear Physics: How Ice Screws Keep Ice Climbers from Falling to Their Deaths




Limited testing by Chris Harmston of Black Diamond and Craig Luebben about 10 years ago showed that ice screws with the hanger end angled down (negative angle) up to 20 degrees were stronger than screws with the hanger parallel to the ice or angled slightly up (positive angle). A negative angle does not, however, increase the strength of the threads; rather, it decreases the chance that the ice will blow out from under the screw.




Should I Angle Ice Screws Down?




Contrary to what you might think, the best angle for the screws is slightly upward, meaning the hanger is slightly lower than the teeth in the ice. This counterintuitive method is better because the holding power comes from the threads themselves and not from a “snow picket” effect, meaning you don’t get any mechanical advantage having the shaft of the screw levered against the ice (Fig. 2).




How to Build Bomber Ice Anchors




It was once thought necessary or beneficial for ice-screws to be place horizontally or with the hanger up for optimum hold. However, it has since been found experimentally that a screw place with the tip angled up often holds as well or better. This surprising result is thought to be due to the previously underestimated role of the threads in holding the screw in place. However, horizontal placements are usually recommended.




Wikipedia



So you would want to angle them up into the ice.






share|improve this answer




















  • Wow! That's something that's so counter-intuitive!
    – Ricketyship
    1 hour ago










  • Can we have some pictures? I'm confused with all the ups and downs :D
    – OddDeer
    1 hour ago










  • @Oddeer see the first source
    – Charlie Brumbaugh
    1 hour ago










  • This is a good answer, but perhaps you should add that the single most important factor for ice anchor strength is ice quality. Ensure that all threads engage in solid ice and that the screw is driven all the way in.
    – Guran
    26 mins ago














up vote
4
down vote













All of the resources that I can find say that it should be done with the end pointing up and the hanger down with up to a twenty degree angle from vertical.




More surprising were Harmston's findings about screw angle. As it turns out, screws hold much better when they're angled in the direction of the falling force, as in the second scenario above. Perhaps needless to say, this is not intuitive. Much of the force is then resisted by the threads rather than the girth of the screw itself. This isn't a small difference either: an ice screw placed at a downward angle is as much as twice as strong as a screw placed at an upward "negative" angle.




Gear Physics: How Ice Screws Keep Ice Climbers from Falling to Their Deaths




Limited testing by Chris Harmston of Black Diamond and Craig Luebben about 10 years ago showed that ice screws with the hanger end angled down (negative angle) up to 20 degrees were stronger than screws with the hanger parallel to the ice or angled slightly up (positive angle). A negative angle does not, however, increase the strength of the threads; rather, it decreases the chance that the ice will blow out from under the screw.




Should I Angle Ice Screws Down?




Contrary to what you might think, the best angle for the screws is slightly upward, meaning the hanger is slightly lower than the teeth in the ice. This counterintuitive method is better because the holding power comes from the threads themselves and not from a “snow picket” effect, meaning you don’t get any mechanical advantage having the shaft of the screw levered against the ice (Fig. 2).




How to Build Bomber Ice Anchors




It was once thought necessary or beneficial for ice-screws to be place horizontally or with the hanger up for optimum hold. However, it has since been found experimentally that a screw place with the tip angled up often holds as well or better. This surprising result is thought to be due to the previously underestimated role of the threads in holding the screw in place. However, horizontal placements are usually recommended.




Wikipedia



So you would want to angle them up into the ice.






share|improve this answer




















  • Wow! That's something that's so counter-intuitive!
    – Ricketyship
    1 hour ago










  • Can we have some pictures? I'm confused with all the ups and downs :D
    – OddDeer
    1 hour ago










  • @Oddeer see the first source
    – Charlie Brumbaugh
    1 hour ago










  • This is a good answer, but perhaps you should add that the single most important factor for ice anchor strength is ice quality. Ensure that all threads engage in solid ice and that the screw is driven all the way in.
    – Guran
    26 mins ago












up vote
4
down vote










up vote
4
down vote









All of the resources that I can find say that it should be done with the end pointing up and the hanger down with up to a twenty degree angle from vertical.




More surprising were Harmston's findings about screw angle. As it turns out, screws hold much better when they're angled in the direction of the falling force, as in the second scenario above. Perhaps needless to say, this is not intuitive. Much of the force is then resisted by the threads rather than the girth of the screw itself. This isn't a small difference either: an ice screw placed at a downward angle is as much as twice as strong as a screw placed at an upward "negative" angle.




Gear Physics: How Ice Screws Keep Ice Climbers from Falling to Their Deaths




Limited testing by Chris Harmston of Black Diamond and Craig Luebben about 10 years ago showed that ice screws with the hanger end angled down (negative angle) up to 20 degrees were stronger than screws with the hanger parallel to the ice or angled slightly up (positive angle). A negative angle does not, however, increase the strength of the threads; rather, it decreases the chance that the ice will blow out from under the screw.




Should I Angle Ice Screws Down?




Contrary to what you might think, the best angle for the screws is slightly upward, meaning the hanger is slightly lower than the teeth in the ice. This counterintuitive method is better because the holding power comes from the threads themselves and not from a “snow picket” effect, meaning you don’t get any mechanical advantage having the shaft of the screw levered against the ice (Fig. 2).




How to Build Bomber Ice Anchors




It was once thought necessary or beneficial for ice-screws to be place horizontally or with the hanger up for optimum hold. However, it has since been found experimentally that a screw place with the tip angled up often holds as well or better. This surprising result is thought to be due to the previously underestimated role of the threads in holding the screw in place. However, horizontal placements are usually recommended.




Wikipedia



So you would want to angle them up into the ice.






share|improve this answer












All of the resources that I can find say that it should be done with the end pointing up and the hanger down with up to a twenty degree angle from vertical.




More surprising were Harmston's findings about screw angle. As it turns out, screws hold much better when they're angled in the direction of the falling force, as in the second scenario above. Perhaps needless to say, this is not intuitive. Much of the force is then resisted by the threads rather than the girth of the screw itself. This isn't a small difference either: an ice screw placed at a downward angle is as much as twice as strong as a screw placed at an upward "negative" angle.




Gear Physics: How Ice Screws Keep Ice Climbers from Falling to Their Deaths




Limited testing by Chris Harmston of Black Diamond and Craig Luebben about 10 years ago showed that ice screws with the hanger end angled down (negative angle) up to 20 degrees were stronger than screws with the hanger parallel to the ice or angled slightly up (positive angle). A negative angle does not, however, increase the strength of the threads; rather, it decreases the chance that the ice will blow out from under the screw.




Should I Angle Ice Screws Down?




Contrary to what you might think, the best angle for the screws is slightly upward, meaning the hanger is slightly lower than the teeth in the ice. This counterintuitive method is better because the holding power comes from the threads themselves and not from a “snow picket” effect, meaning you don’t get any mechanical advantage having the shaft of the screw levered against the ice (Fig. 2).




How to Build Bomber Ice Anchors




It was once thought necessary or beneficial for ice-screws to be place horizontally or with the hanger up for optimum hold. However, it has since been found experimentally that a screw place with the tip angled up often holds as well or better. This surprising result is thought to be due to the previously underestimated role of the threads in holding the screw in place. However, horizontal placements are usually recommended.




Wikipedia



So you would want to angle them up into the ice.







share|improve this answer












share|improve this answer



share|improve this answer










answered 1 hour ago









Charlie Brumbaugh

41.7k14111239




41.7k14111239











  • Wow! That's something that's so counter-intuitive!
    – Ricketyship
    1 hour ago










  • Can we have some pictures? I'm confused with all the ups and downs :D
    – OddDeer
    1 hour ago










  • @Oddeer see the first source
    – Charlie Brumbaugh
    1 hour ago










  • This is a good answer, but perhaps you should add that the single most important factor for ice anchor strength is ice quality. Ensure that all threads engage in solid ice and that the screw is driven all the way in.
    – Guran
    26 mins ago
















  • Wow! That's something that's so counter-intuitive!
    – Ricketyship
    1 hour ago










  • Can we have some pictures? I'm confused with all the ups and downs :D
    – OddDeer
    1 hour ago










  • @Oddeer see the first source
    – Charlie Brumbaugh
    1 hour ago










  • This is a good answer, but perhaps you should add that the single most important factor for ice anchor strength is ice quality. Ensure that all threads engage in solid ice and that the screw is driven all the way in.
    – Guran
    26 mins ago















Wow! That's something that's so counter-intuitive!
– Ricketyship
1 hour ago




Wow! That's something that's so counter-intuitive!
– Ricketyship
1 hour ago












Can we have some pictures? I'm confused with all the ups and downs :D
– OddDeer
1 hour ago




Can we have some pictures? I'm confused with all the ups and downs :D
– OddDeer
1 hour ago












@Oddeer see the first source
– Charlie Brumbaugh
1 hour ago




@Oddeer see the first source
– Charlie Brumbaugh
1 hour ago












This is a good answer, but perhaps you should add that the single most important factor for ice anchor strength is ice quality. Ensure that all threads engage in solid ice and that the screw is driven all the way in.
– Guran
26 mins ago




This is a good answer, but perhaps you should add that the single most important factor for ice anchor strength is ice quality. Ensure that all threads engage in solid ice and that the screw is driven all the way in.
– Guran
26 mins ago

















 

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