Cómo funciona
La rosca métrica ISO (ISO 261, ISO 724) tiene un perfil de 60°; el paso grueso es el estándar, mientras que el paso fino se utiliza en piezas de pared delgada y ajustes finos. UNC y UNF son las series gruesa y fina del sistema de roscas Unified, indicadas en hilos por pulgada (TPI).
Fórmula
d2 = d − 0.6495·P d3 = d − 1.2269·P D1 = d − 1.0825·P As = π/4 · ((d2 + d3)/2)² tap drill ≈ d − P
La broca de roscar es aproximadamente el diámetro nominal menos el paso, lo que da un 75–80 % de recubrimiento de rosca. En materiales duros o roscas largas suele ser mejor una broca 0,1–0,2 mm mayor. La sección resistente es la base de los cálculos de resistencia de tornillos.
Tabla
| Rosca | P mm | d2 mm | d3 mm | As mm² | Broca mm |
|---|---|---|---|---|---|
| Métrica gruesa (ISO 261) | |||||
| M1.6 | 0,35 | 1,373 | 1,171 | 1,3 | 1,25 |
| M2 | 0,40 | 1,740 | 1,509 | 2,1 | 1,60 |
| M2.5 | 0,45 | 2,208 | 1,948 | 3,4 | 2,05 |
| M3 | 0,50 | 2,675 | 2,387 | 5,0 | 2,50 |
| M4 | 0,70 | 3,545 | 3,141 | 8,8 | 3,30 |
| M5 | 0,80 | 4,480 | 4,019 | 14,2 | 4,20 |
| M6 | 1,00 | 5,350 | 4,773 | 20,1 | 5,00 |
| M8 | 1,25 | 7,188 | 6,466 | 36,6 | 6,75 |
| M10 | 1,50 | 9,026 | 8,160 | 58,0 | 8,50 |
| M12 | 1,75 | 10,863 | 9,853 | 84,3 | 10,25 |
| M14 | 2,00 | 12,701 | 11,546 | 115,4 | 12,00 |
| M16 | 2,00 | 14,701 | 13,546 | 156,7 | 14,00 |
| M18 | 2,50 | 16,376 | 14,933 | 192,5 | 15,50 |
| M20 | 2,50 | 18,376 | 16,933 | 244,8 | 17,50 |
| M22 | 2,50 | 20,376 | 18,933 | 303,4 | 19,50 |
| M24 | 3,00 | 22,051 | 20,319 | 352,5 | 21,00 |
| M27 | 3,00 | 25,051 | 23,319 | 459,4 | 24,00 |
| M30 | 3,50 | 27,727 | 25,706 | 560,6 | 26,50 |
| M33 | 3,50 | 30,727 | 28,706 | 693,6 | 29,50 |
| M36 | 4,00 | 33,402 | 31,093 | 816,7 | 32,00 |
| M39 | 4,00 | 36,402 | 34,093 | 975,8 | 35,00 |
| M42 | 4,50 | 39,077 | 36,479 | 1.120,9 | 37,50 |
| M48 | 5,00 | 44,752 | 41,866 | 1.473,1 | 43,00 |
| M56 | 5,50 | 52,428 | 49,252 | 2.030,0 | 50,50 |
| M64 | 6,00 | 60,103 | 56,639 | 2.676,0 | 58,00 |
| Métrica fina | |||||
| M8×1 | 1,00 | 7,350 | 6,773 | 39,2 | 7,00 |
| M10×1 | 1,00 | 9,350 | 8,773 | 64,5 | 9,00 |
| M10×1.25 | 1,25 | 9,188 | 8,466 | 61,2 | 8,75 |
| M12×1.25 | 1,25 | 11,188 | 10,466 | 92,1 | 10,75 |
| M12×1.5 | 1,50 | 11,026 | 10,160 | 88,1 | 10,50 |
| M14×1.5 | 1,50 | 13,026 | 12,160 | 124,5 | 12,50 |
| M16×1.5 | 1,50 | 15,026 | 14,160 | 167,2 | 14,50 |
| M18×1.5 | 1,50 | 17,026 | 16,160 | 216,2 | 16,50 |
| M20×1.5 | 1,50 | 19,026 | 18,160 | 271,5 | 18,50 |
| M22×1.5 | 1,50 | 21,026 | 20,160 | 333,1 | 20,50 |
| M24×2 | 2,00 | 22,701 | 21,546 | 384,4 | 22,00 |
| M27×2 | 2,00 | 25,701 | 24,546 | 495,7 | 25,00 |
| M30×2 | 2,00 | 28,701 | 27,546 | 621,2 | 28,00 |
| M33×2 | 2,00 | 31,701 | 30,546 | 760,8 | 31,00 |
| M36×3 | 3,00 | 34,051 | 32,319 | 864,9 | 33,00 |
| M39×3 | 3,00 | 37,051 | 35,319 | 1.028,4 | 36,00 |
| M42×3 | 3,00 | 40,051 | 38,319 | 1.206,0 | 39,00 |
| M48×3 | 3,00 | 46,051 | 44,319 | 1.603,6 | 45,00 |
| UNC | |||||
| #4-40 UNC | 0,635 | 2,432 | 2,066 | 3,9 | 2,21 |
| #6-32 UNC | 0,794 | 2,990 | 2,531 | 5,9 | 2,71 |
| #8-32 UNC | 0,794 | 3,650 | 3,192 | 9,0 | 3,37 |
| #10-24 UNC | 1,058 | 4,139 | 3,528 | 11,3 | 3,77 |
| 1/4-20 UNC | 1,270 | 5,525 | 4,792 | 20,5 | 5,08 |
| 5/16-18 UNC | 1,411 | 7,021 | 6,206 | 33,8 | 6,53 |
| 3/8-16 UNC | 1,587 | 8,494 | 7,577 | 50,0 | 7,94 |
| 7/16-14 UNC | 1,814 | 9,934 | 8,887 | 68,6 | 9,30 |
| 1/2-13 UNC | 1,954 | 11,431 | 10,303 | 91,5 | 10,75 |
| 9/16-12 UNC | 2,117 | 12,913 | 11,691 | 117,4 | 12,17 |
| 5/8-11 UNC | 2,309 | 14,375 | 13,042 | 145,8 | 13,57 |
| 3/4-10 UNC | 2,540 | 17,400 | 15,934 | 215,8 | 16,51 |
| 7/8-9 UNC | 2,822 | 20,392 | 18,763 | 297,9 | 19,40 |
| 1-8 UNC | 3,175 | 23,338 | 21,505 | 390,8 | 22,22 |
| UNF | |||||
| #4-48 UNF | 0,529 | 2,501 | 2,196 | 4,3 | 2,32 |
| #6-40 UNF | 0,635 | 3,093 | 2,726 | 6,5 | 2,87 |
| #8-36 UNF | 0,706 | 3,707 | 3,300 | 9,5 | 3,46 |
| #10-32 UNF | 0,794 | 4,310 | 3,852 | 12,9 | 4,03 |
| 1/4-28 UNF | 0,907 | 5,761 | 5,237 | 23,5 | 5,44 |
| 5/16-24 UNF | 1,058 | 7,250 | 6,639 | 37,5 | 6,88 |
| 3/8-24 UNF | 1,058 | 8,838 | 8,227 | 56,7 | 8,47 |
| 7/16-20 UNF | 1,270 | 10,288 | 9,554 | 76,6 | 9,84 |
| 1/2-20 UNF | 1,270 | 11,875 | 11,142 | 103,2 | 11,43 |
| 9/16-18 UNF | 1,411 | 13,371 | 12,556 | 131,0 | 12,88 |
| 5/8-18 UNF | 1,411 | 14,958 | 14,144 | 165,1 | 14,46 |
| 3/4-16 UNF | 1,587 | 18,019 | 17,102 | 240,6 | 17,46 |
| 7/8-14 UNF | 1,814 | 21,047 | 19,999 | 328,7 | 20,41 |
| 1-12 UNF | 2,117 | 24,025 | 22,803 | 427,8 | 23,28 |
Todos los cálculos se realizan en tu navegador; los datos que introduces nunca nos llegan.