I didn't get these for sewing, but rather to cut a zigzag edge on vacuum-sealed bags of backpacking meals so that a utensil (knife, scissors, etc.) isn't required to get the bag open while in the field.  Sharp as all get-out, heavy blades, they make such a NICE little edge that creates tear points along the bag.  GREAT price, too...even Wally World's offerings were more expensive and, from what I saw in the store, less sturdy.  The handles are plastic, but ergonomically molded to offer maximum comfort during repeated or extended use.  For the price, you can't beat these pinkers!