Steve Morris from Rock Hardware on karabiners and removable bolt hangers
I am confident that most climbers know not to use wire gate kara-biners on removable bolt hangers. There is not enough mass in the wire gate to keep the bolt plate captive on the bolt head. These stainless steel bolts in the rock are often referred to as “carrot” bolts. 3/8” use to be common; however, 10mm appears to have taken its place. Solid gate karabiners are the preferred option when you find carrot bolts and have to use removable bolt plates for protection.
In the last few years it has come to my attention that some straight gate karabiners can come off removable bolt hangers. Particularly, karabiners with a key lock nose. The reason for this is because the nose of the key lock karabiner can be quite thin. In the same way a wire gate karabiner can come off with the removable bolt plate, so can a straight gate karabiner with a thin nose profile. I recently tried a dozen or more different straight gate karabiners on a carrot bolt and most hangers came off. Scary stuff!
One option is to clip your straight gate from the front of the hanger, instead of from below. You then rotate the body of the karabiner until the bottom basket of the karabiner is sitting in the bolt plate, keeping it captive on the bolt head. In other words, the nose of the karabiner is well away from the carrot bolt and hanger.
Another option is to use traditional straight gate karabiners with a solid hook type nose that has a solid mass and is not tapered.
This controversy only applies to carrot type bolts and removable bolt hangers. You can use wire gate karabiners in fixed hangers and this practice is common in Europe. Think about how you can safely protect a climb at all times.
I trust this information may assist in keeping you safer while climbing.