| | | 3M™ Nextel™ Sewing Thread Nextel™ Sewing Threads 312 and 440 are high h temperature machine sewable threads made from continuous Nextel Alumina-Boria-Silica Fibers. Nextel 312 sewing threads offer superior high ■ ■■■ temperature resistance to 2012°F (1100°C). The Nextel 440 threads are resistant to 2500°F (1307°C). Both are ideal for sewing Nextel textiles and other high temperature fabrics. The Nextel 312 and 440 sewing threads are a combination of ceramic fibers and rayon fibers. The rayon fibers impart resiliency and abrasion resistance to the threads to improve sewability. The rayon is heat fugitive, i.e., the fibers decompose at temperatures above approximately 572°F (300°C). The amount of rayon in the thread is about 10 percent by weight. | | |
| | | | | | | | | | | | | | | | | | | | Style | Diameter | Approximate Yield | Sized Strength | Heat Cleaned Strength | | | | Breaking | Knot | Breaking | Knot | | | | inch | (mm) | yd/lb | m/kg | lbs | (kg) | lbs | (kg) | lbs | (kg) | lbs (kg) | | | | Nextel 312 | | | | | | | | | | | | | | | AT-21 | 0.019 | (0,48) | 1570 | (3160) | 27 | (12,2) | 5 | (2,3) | 10 | (4,5) | 3 (1,4) | | | | AT-30 | 0.028 | (0,71) | 810 | (1630) | 47 | (21,3) | 14 | (6,4) | 15 | (6,8) | 8 (3,6) | | | | Nextel 440 | | | | | | | | | | | | | | | BT-30 | 0.029 | (0,74) | 710 | (1430) | 44 | (20,0) | 6 | (2,7) | 25 | (11,3) | 6 (2,7) | | | | | | | | | | | | | | | | | | | |
| | | 312 Fiber Properties: Composition -Alumina-Boria-Silica Density (non-porous) - .0975 lb/in3 (2,70 gm/cc) Tensile Strength -25 0x103 psi (1720 MPa) Continuous Use Temperature - 2200°F (1240°C) Short Term Use Temperature - 2600°F (1427°c) Melt Temperature - 3272°F (1800°C) Other Characteristics -Non-oxidizing, non-hygroscopic, essentially chemically resistant, low thermal conductivity, good abrasion resistance. | | 440 Fiber Properties: Composition -Alumina-Boria-Silica Density (non-porous) - .1085 lb/in3 (3,05 gm/cc) Tensile Strength -300x103 psi (2070 MPa) Continuous Use Temperature - 2500°F (1370°C) Short Use Temperature - 3000°F (1704°C) Melt Temperature - 3272°F (1800°C) Other Characteristics -Non-oxidizing, non-hygroscopic, essentially chemically resistant, low thermal conductivity, good abrasion resistance. | | |