This tubing:
Sterling Silver Tubing fits Pandora Chain.
Size 5.08mm OD/ 4.37mm ID 27 ga.
Manufacture pre-cut in 1 foot lengths
is a PERFECT fit for 3/16" mandrels and is made by:
Indian Jewelers Supply, Inc.
Part number STTB27x5mm
1-800-545-6540
This thread shows this tubing cored and on a pandora chain so you can see how it fits over the end:
http://www.lampworketc.com/forums/sh...&postcount=132