A Barrel Clasp has two identical looking halves that screw together so the fastened clasp looks a little like the shape of a barrel. A Torpedo Clasp is essentially the same as a barrel clasp, but slightly narrower and more elongated.
Pros: These types of clasp are extremely secure and are available at a low cost. Barrel clasps were some of the first that I ever bought as I found a large wholesale packet in a bead shop and I recognised their style from jewellery that I already owned. This was back in the day before I knew about the whole range of clasps available and before I had learned that different styles of clasp are definitely suited to different jewellery designs.
Cons: I quickly discovered that you definitely need two hands in order to fasten barrel clasps, so it’s very tricky on a bracelet. Be wary of very cheap brands as I have found that the screw thread is not always completely reliable. Remember that large, cheap wholesale pack I picked up? Well, unfortunately the barrel clasps it contained proved to be a little unreliable over the long term!
I like using barrel clasps in necklace designs where I need a clasp that isn’t going to be too obtrusive. Personally, I find the screw mechanism a little easier to use than a bolt ring as trying to pull back that tiny bit of metal on the bolt rings often ends up in broken finger nails and a lot of frustration. However, I know plenty of people who would disagree with me there and find that barrel clasps are tricky to fasten as it can be hard to get the screw mechanism aligned correctly at first. Certainly, if you are wearing (or selling) jewellery with a barrel clasp, do make very certain that you have screwed the two ends together as tightly as possible to avoid your jewellery unfastening as you wear it.