No crimping tool is needed for these cap seals. They will snap on by hand, but they have to be destroyed to remove them. This gives you the added security of knowing that your product is safe inside. The tamper evident feature of these cap seals lets you fill your drums with your product and ship or store knowing that the contents inside will be protected. Make sure you get the right style. If your drum is a Greif drum, you will want the GCS200. Only this snap on cap seal will fit this Greif drums. Same goes for the MCP200. These plastic drums each have their own styles. Grab some cap seals today. It's a snap.