Calissa Offshore Tackle Heavy Duty Snap Setter Fastener Pliers Tool Kit for Fastening Metal Snap Rings – Vise Grip Marine Grade Canvas Tarp Boat Cover Installation, Sewing, Repair Set

The design of this tool is simple but effective: It is locking pliers (like Vise-Grips®) with with dies welded to the jaws that fit 5/8-inch-outside-diameter snaps (caps and bases). It appears to me that the manufacturer purchases the pliers and simply welds dies onto the pliers' jaws. The pliers appear to be of good quality. The weld looks like it will outlast the pliers.One die is simply a shallow cylindrical recess with an inside diameter to fit a 5/8-inch-outside-diameter snap cap or base. The other die has a nub at the center of a 3/8-inch-diameter table. Operation: You place a cap or base in the recessed die, place a socket or stud on the other die with the nub through the center hole of the socket or stud, position the pliers so the two jaws are on opposite sides of canvas, and close the jaws. When the pliers are closed, the nub strikes the open top of the cylindrical post of the cap or base and flares it to crimp the socket onto the cap or the stud onto the base. The lever action that tightens the jaws of the pliers allows the the dies to be pressed together with great force to achieve excellent crimps.I believe 5/8-inch outside diameter of cap and base (3/8-inch inside diameter of socket) is by far the most common canvas-snap size, but there are other sizes. This tool could not be used for larger-diameter snaps. I don't know how well this tool would work for smaller ones; they might not stay centered under the nub, in which case it might flare the post poorly. The dies are not changeable. I believe there are other products that offer interchangeable dies, but I haven't seen any with lever action to increase the crimping force.As long as snap-size is not an issue, these pliers are an excellent tool.

I used this to add some snaps to the back of the seats in my car that have a cover for cargo. It previously had velcro that went bad. This tool did the job! Pretty straightforward once you get the hang of it. Works great. Very sturdy tool too. I appreciate that it came with everything i needed, including the snaps.

This tool works well; It is strong, sturdy, and well made. The tool works very well when installing bottons/snaps that do not have to be installed to far from the edge of the material being used. However, because of the tool's design it has a limited inward reach which makes it somewhat more difficult to set buttons and snaps further in from the edge of the fabric on which they are being installed.

We used this kitty to put snaps on this boat cover to make it fit snugly to keep rain from pooling. We used the already installed snaps (male parts) and just popped in female snaps all the way around and it worked! It took some practice so I suggest you use a scrap piece to practice on. Works great! There is a plethora of snaps. We just wish that it came with more of a variety of sizes of snaps.

Good deal. Sturdy and strong. Basically vice grips with snap tool attached. A little heavy but works fine. Used it to replace and add snaps on my boat cover.

The tool is excellent. Easy to use and adding snaps is pretty quick and easy. (It's a snap) :) That is good because the snaps themselves do not hold up. I replaced every snap within 3 months of use. I take my boat cover off and on every weekend in the summer. If anyone knows good sturdy snaps, let me know.

Works as it should

There are two major issues. First, the tool does not hold the snap together before it crimps. It should have a spring that holds the snap together before it begins crimping. Second, the pliers are sloppy and the crimp is always mashed sideways. The snaps almost always pull apart. The hammer, punch and anvil works well so I know the problem is not the snap.