Metallic FS 15 300m
Madeira FS15 is a slight oddity in the Madeira Metallic range as it is the only one of Madeira Metallic threads that is strong enough for construction, all the others are purely decorative. (FS15 was originally designed to sew Jeans!)
A No.15 weight thread is one of the heaviest metallic threads.
The Recommended Needle is: Topstitch Size 90/14