The most commonly used fasteners in Prosthetics and Orthotics are rivets. Speedy and copper rivets are staples to the field. These rivets can be used to attach:

  • straps to an orthotic device with speedy rivets.

  • a suspension system to a prosthesis with copper rivets and a grommet (such as an elastic hip belt).

  • Metal uprights to another piece of metal with copper rivets.

Speedy Rivets

Named for their ease of use, aluminum speedy rivets are used mostly in orthotics. They come in a large number of sizes (in thickness and length) and have flat or capped ends. Hockey tape can be used to cover rivets for a seamless and low profile on the interior of devices.

Riveting

  1. Drill a hole in both items to be riveted ( or hole punched if using a strap). The most often used speedy rivet size at GBC can fit into a 9/64" hole.

  2. Insert the male piece (the base) into the chosen side (usually facing away from the inner surface) and through both items.

  3. Place the female piece (Button) over the eyelet, and hold the inside against a riveting bar that covers the entire rivet.

  4. In a couple of well aimed hits of the hammer the rivet will be secure.

NOTE: You do not have to completely flatten the rivet. Excessive strikes can weaken the bond or cause old plastic to fracture. Some fittings require the rivets to be loosely secured for easy removal.

Removal

Slide a forked flat head screwdriver (pry bar) under the rivet head and pry up, popping off the button of the rivet. Snip the mushroomed eyelet with side cutters to allow the rivet to fall through the pieces.

Alternatively an old or cheap pair of side cutters can be ground flush to the cutting blades and slid under the button, cutting the eyelet and button off together.

Copper Rivets

Copper rivet are typically used in prosthetics and are much stronger than speedy rivets. These are available in many shapes and sizes. A 5/32" bit should be sufficient for most copper rivet work.

There are two main methods of attaching a copper rivet. The first is using a spacer to attach a strap that can rotate. A burr will be used to secure the rivet in place. The second option will require the outer surface (typically metal) to be countersunk, hammering the cut end of the copper rivet into the recessed area.

Riveting a Strap

  1. Drill/punch the correct size hole through the items being attached.

  2. Countersink the inner surface of the socket, to make space for the rivet's head.

  3. Round the head of the rivet, to make it smoother on the inside. This can be done with a hammer and the rivet inserted into a fletcher tool.  Put the fletcher in a vice, insert the rivet in that and tap the edge of the rivet with a hammer, making sure that it is rounded evenly.

  4. Insert the rivet into the holes, with the head on the inside. If you want the strap to be able to rotate, add a piece of 1/16" polyethylene, or another piece of thin material.

  5. place the rivet head onto a flat surface and put the burr on the male end of the rivet. Use the fletcher and hammer to drive the grommet to the material, hammer it snug. As few hits as necessary, too many can deform the burr rendering it useless.

  6. Use cutters to remove as much excess material as possible from the male end.

  7. Use your domer and hammer to round the remaining material.

Permanent Riveting

  1. Drill the correct size clearance holes in the materials

  2. On the outer piece of material, countersink to create a recess that will later be filled with the male part of the rivet.

  3. Round the head of the rivet, to make it smoother on the inside. This can be done with a hammer and the rivet inserted into a fletcher tool.  Put the fletcher in a vice, insert the rivet in that and tap the edge of the rivet with a hammer, making sure that it is rounded evenly.

  4. Insert the rivet into the material, and using cutters, remove the excess material.

  5. Place the rivet head on a flat surface and hammer the remaining rivet flat into the space created, making sure to fill the whole cavity.

  6. Grind the rivet smooth to the material for a uniform finish.

Removal

Use a punch to drive the rivet through the materials.

Alternatively an old or cheap pair of side cutters can be ground flush to the cutting blades and slid under the burr, prying it up slightly. Grip one end of the raised burr and twist it off the domed end. Snip off the domed end to allow it to slide easily through both materials.

Rivets can also be drilled through although it may be hard to perfectly position your bit on the domed ends of the rivet.

The domed end can be ground off, though the heat generated from this method should be taken into consideration.

For countersunk rivets a pilot hole and countersink can remove these stubborn rivets.