These are one of the most widely used pins among sewers. Made out of nickel-plated steel, they're strong but not overly flexible. (Pins with softer metal shafts can be bendy, making it that much harder to pin back up through fabric layers). The glass head won't melt under the heat of the iron. Use these pins when you need to hold materials down during pressing or as your "go to" pins for all your general sewing and quilting needs.