Coats 15wt Extra Strong and Upholstery Thread is 100 bonded nylon for machine and hand sewing of upholstery, outdoor and heavyweight fabrics and is weather resistant. It is available in a range of 8 colors. 3 spools per box, 150yds per spool, 240 spools per case. Machine needle size: 16 or18. Hand Needle size: 1, 2, 3, 4 or 5.