For Japan made full size and portable blindstitch hemmer machines, most in USA from Yamagata JAPAN, Center Manufacturing Company.

Alternative Needle System Numbers: 251E, LWx5T, SY7425, 20C300LG, 29CB, 29BNL, 300G

U.S. Blindstitch :718, 718-C, 718-2, 1118, 118-C, 1099.
US Stitchline SL718-2
Columbia : T1718, T175
Consew 718, 1118-2, 75C (not 75T)
Union Special 99KS blindstitch machine
A needle system is a group of needles made to fit specific sewing machines. All needles in a system are of the same length and shank size, but are of various diameters. Lower size numbers are narrower or thinner needles used for lighter materials. Higher size numbers indicate a needle of thicker diameter, used for heavier materials. Match your needle system to your machine, then the size of the needle to the product you are sewing.

Needle Sizes Available for Light, Medium, and Heavy Weight apparel, drapery, and interior fabrics (not upholstery)

Size 8 (Metric Size 60) Light
Size 9 (Metric Size 65) Blindstitch Size 2.0, for Light
Size 10 (Metric Size 70) Blindstitch Size 2.5, for Light
Size 11 (Metric Size 75) Blindstitch Size 3.0, for Light
Size 12 (Metric Size 80) Medium
Size 13 (Metric Size 85) Medium
Size 14 (Metric Size 90) Blindstitch Size 3.5, for Medium
Size 15 (Metric Size 95) Heavy
Size 16 (Metric Size 100) Blinndstitch Size 4.0, for Heavy
Size 18 (Metric Size 110) Blindstitch Size 4.5, for Heavy