We use these solid brass 12-24 machine screws, 1/2" long, and matching washers for fastening machine-stamped rivet-style bells onto leather about 1/8" thick.
Note: If you are working with rivet-style bells made by pouring melted metal into molds, fasten them with our smaller 10-32 screws....
How to prepare rivet bells to be reused: Cut or pull all the bells off the old leather strap. If large pieces of leather still remain around the metal rivet after removing the bell from the old strap, remove as much of that extra leather as is practical.
Use a bolt cutter, Dremel tool, or other cutting tool to remove the head from each rivet. The head of each rivet is the metal "dot" you see on the bottom of each bell.
A cylindrical stub of the old rivet will remain in the hole after the head is removed. This stub goes all the way through the base of the bell and is held in this hole by a tight friction fit.
Use a pin punch or nail set (available at hardware stores) to drive this stub through the bell into the hollow center of the bell.
TIP: You can first flatten the surface of the rivet with a belt sander or grinder to make it easier to drive the stub through the bell. If you do decide to use a belt sander or grinder, watch the video (link is below) before you start.
If possible, remove the rivet stub from inside the bell by pulling it out through one of the clean-out holes that surround the bottom of the bell.
You may have to enlarge a clean-out hole slightly before the stub can be removed.
Some sturdy double-throat (two slit) bells do not have clean-out holes. In that case, open one of the slits on top of the bell to make the gap wide enough so the stub can fall out through the gap. After removing the stub, tap the "leaves" of the bell to reset the gap back to its original width.
CAUTION: The rivet stub cannot be removed from all types of machine-stamped bells. Some bells were fastened with a specialized rivet designed to reinforce the bottom of the bell. This type of rivet is physically too large to be removed without taking the bell apart. Other types of machine-stamped bells are so fragile they cannot be manipulated much without damaging the bell.
The hole where the rivet once was should now be tapped to accept a machine screw. Use a #12-24 tap (available at hardware stores) to cut the correct thread for the screw sold in this listing.
How to install rivet bells on a new strap: Make a new strap and punch round holes as required along the new leather strap, one hole for each bell. I use a 7/32" diameter round punch for #12 screws.
Insert a screw through a finish washer, then push the screw through one of the holes in the strap. You want the washer and head of the screw to be on the backside of the leather strap.
Add a small drop of threadlocker fluid (Loctite is a common brand) or nail polish to the screw threads that are sticking out from the front side of the strap.
Thread the bell onto the screw and tighten until the base of the bell is firmly seated into the leather.
CAUTION: Do not over tighten, or you may strip the threads in the soft brass. Video of putting bells on a strap: https://youtu.be/dAka9nQ71Es
Sold per set of screw and washer.
