20 inch

Key to six sheave J-Block Model Numbers
| J | 30 | SX | 14 | B | T | A |
| Shorty “J” Crane Block | Safe Working Limit-Tons |
Number of Sheaves SX = 6 |
Sheave Size – Nom. O.D. |
Sheave Bearing: B = Bronze Bushed |
Hook-Thrust Bearing |
Cheek Weights: |
| Model | WT. | A | B | E | F | H | J | K |
| Overall | Net | Thickness | Throat
Opening |
Hook | Hook | |||
| Length | Length | Width | w/Latch | Thick. | Width | |||
| J65SX20BTA | 1448 | 61.250 | 49.375 | 22.187 | 24.750 | 4.36 | 6.250 | 4.500 |
| J65SX20BTB | 1748 | 61.250 | 49.375 | 24.812 | 24.750 | 4.36 | 6.250 | 4.500 |
| J65SX20BTC | 2090 | 61.250 | 49.375 | 29.812 | 24.750 | 4.36 | 6.250 | 4.500 |
| J65SX20RTA | 1448 | 61.250 | 49.375 | 22.187 | 24.750 | 4.36 | 6.250 | 4.500 |
| J65SX20RTB | 1748 | 61.250 | 49.375 | 24.812 | 24.750 | 4.36 | 6.250 | 4.500 |
| J65SX20RTC | 2090 | 61.250 | 49.375 | 29.812 | 24.750 | 4.36 | 6.250 | 4.500 |
| J70SX20BTA | 1448 | 61.250 | 49.375 | 22.187 | 24.750 | 4.36 | 6.250 | 4.500 |
| J70SX20BTB | 1748 | 61.250 | 49.375 | 24.812 | 24.750 | 4.36 | 6.250 | 4.500 |
| J70SX20BTC | 2090 | 61.250 | 49.375 | 29.812 | 24.750 | 4.36 | 6.250 | 4.500 |
| J70SX20RTA | 1448 | 61.250 | 49.375 | 22.187 | 24.750 | 4.36 | 6.250 | 4.500 |
| J70SX20RTB | 1748 | 61.250 | 49.375 | 24.812 | 24.750 | 4.36 | 6.250 | 4.500 |
| J70SX20RTC | 2090 | 61.250 | 49.375 | 29.812 | 24.750 | 4.36 | 6.250 | 4.500 |
| J75SX20BTA | 1822 | 65.625 | 53 | 22.187 | 24.750 | 4.750 | 7 | 4.750 |
| J75SX20BTB | 2122 | 65.625 | 53 | 24.812 | 24.750 | 4.750 | 7 | 4.750 |
| J75SX20BTC | 2466 | 65.625 | 53 | 29.812 | 24.750 | 4.750 | 7 | 4.750 |
| J75SX20RTA | 1822 | 65.625 | 53 | 22.187 | 24.750 | 4.750 | 7 | 4.750 |
| J75SX20RTB | 2122 | 65.625 | 53 | 24.812 | 24.750 | 4.750 | 7 | 4.750 |
| J75SX20RTC | 2466 | 65.625 | 53 | 29.812 | 24.750 | 4.750 | 7 | 4.750 |
| J80SX20BTA | 1822 | 65.625 | 53 | 22.187 | 24.750 | 4.750 | 6.75 | 4.750 |
| J80SX20BTB | 2122 | 65.625 | 53 | 24.812 | 24.750 | 4.750 | 6.75 | 4.750 |
| J80SX20BTC | 2466 | 65.625 | 53 | 29.812 | 24.750 | 4.750 | 6.75 | 4.750 |
| J80SX20RTA | 1822 | 65.625 | 53 | 22.187 | 24.750 | 4.750 | 6.75 | 4.750 |
| J80SX20RTB | 2122 | 65.625 | 53 | 24.812 | 24.750 | 4.750 | 6.75 | 4.750 |
| J80SX20RTC | 2466 | 65.625 | 53 | 29.812 | 24.750 | 4.750 | 6.75 | 4.750 |
| J90SX20BTA | 2130 | 66.500 | 53.500 | 22.187 | 24.750 | 4.77 | 7.63 | 5.500 |
| J90SX20BTB | 2431 | 66.500 | 53.500 | 24.812 | 24.750 | 4.77 | 7.63 | 5.500 |
| J90SX20BTC | 2775 | 66.500 | 53.500 | 29.812 | 24.750 | 4.77 | 7.63 | 5.500 |
| J90SX20RTA | 2130 | 66.500 | 53.500 | 22.187 | 24.750 | 4.77 | 7.63 | 5.500 |
| J90SX20RTB | 2431 | 66.500 | 53.500 | 24.812 | 24.750 | 4.77 | 7.63 | 5.500 |
| J90SX20RTC | 2775 | 66.500 | 53.500 | 29.812 | 24.750 | 4.77 | 7.63 | 5.500 |
| J100SX20BTA | 2130 | 66.500 | 53.500 | 22.187 | 24.750 | 4.77 | 7.63 | 5.500 |
| J100SX20BTB | 2431 | 66.500 | 53.500 | 24.812 | 24.750 | 4.77 | 7.63 | 5.500 |
| J100SX20BTC | 2775 | 66.500 | 53.500 | 29.812 | 24.750 | 4.77 | 7.63 | 5.500 |
| J100SX20RTA | 2130 | 66.500 | 53.500 | 22.187 | 24.750 | 4.77 | 7.63 | 5.500 |
| J100SX20RTB | 2431 | 66.500 | 53.500 | 24.812 | 24.750 | 4.77 | 7.63 | 5.500 |
| J100SX20RTC | 2775 | 66.500 | 53.500 | 29.812 | 24.750 | 4.77 | 7.63 | 5.500 |
| J115SX20BTA | 2778 | 73.625 | 58.875 | 23.937 | 24.750 | 5.60 | 9.13 | 6 |
| J115SX20BTB | 3078 | 73.625 | 58.875 | 26.437 | 24.750 | 5.600 | 9.13 | 6 |
| J115SX20BTC | 3420 | 73.625 | 58.875 | 31.437 | 24.750 | 5.600 | 9.13 | 6 |
| J115SX20RTA | 2778 | 73.625 | 58.875 | 23.937 | 24.750 | 5.600 | 9.13 | 6 |
| J115SX20RTB | 3078 | 73.625 | 58.875 | 26.437 | 24.750 | 5.600 | 9.13 | 6 |
| J115SX20RTC | 3420 | 73.625 | 58.875 | 31.437 | 24.750 | 5.600 | 9.13 | 6 |
| J125SX20BTA | 2778 | 73.625 | 58.875 | 23.937 | 24.750 | 5.600 | 9.13 | 6 |
| J125SX20BTB | 3078 | 73.625 | 58.875 | 26.437 | 24.750 | 5.600 | 9.13 | 6 |
| J125SX20BTC | 3420 | 73.625 | 58.875 | 31.437 | 24.750 | 5.600 | 9.13 | 6 |
| J125SX20RTA | 2778 | 73.625 | 58.875 | 23.937 | 24.750 | 5.600 | 9.13 | 6 |
| J125SX20RTB | 3078 | 73.625 | 58.875 | 26.437 | 24.750 | 5.600 | 9.13 | 6 |
| J125SX20RTC | 3420 | 73.625 | 58.875 | 31.437 | 24.750 | 5.600 | 9.13 | 6 |
| J130SX20BTA | 2778 | 73.625 | 58.875 | 23.937 | 24.750 | 5.600 | 9.13 | 6 |
| J130SX20BTB | 3078 | 73.625 | 58.875 | 26.437 | 24.750 | 5.600 | 9.13 | 6 |
| J130SX20BTC | 3420 | 73.625 | 58.875 | 31.437 | 24.750 | 5.600 | 9.13 | 6 |
| J130SX20RTA | 2778 | 73.625 | 58.875 | 23.937 | 24.750 | 5.600 | 9.13 | 6 |
| J130SX20RTB | 3078 | 73.625 | 58.875 | 26.437 | 24.750 | 5.600 | 9.13 | 6 |
| J130SX20RTC | 3420 | 73.625 | 58.875 | 31.437 | 24.750 | 5.600 | 9.13 | 6 |
| J140SX20BTA | 2778 | 73.625 | 58.875 | 23.937 | 24.750 | 5.600 | 9.13 | 6 |
| J140SX20BTB | 3078 | 73.625 | 58.875 | 26.437 | 24.750 | 5.600 | 9.13 | 6 |
| J140SX20BTC | 3420 | 73.625 | 58.875 | 31.437 | 24.750 | 5.600 | 9.13 | 6 |
| J140SX20RTA | 2778 | 73.625 | 58.875 | 23.937 | 24.750 | 5.600 | 9.13 | 6 |
| J140SX20RTB | 3078 | 73.625 | 58.875 | 26.437 | 24.750 | 5.600 | 9.13 | 6 |
| J140SX20RTC | 3420 | 73.625 | 58.875 | 31.437 | 24.750 | 5.600 | 9.13 | 6 |
| J150SX20BTA | 2963 | 76.250 | 61 | 23.937 | 24.750 | 5.34 | 9.93 | 7 |
| J150SX20BTB | 3263 | 76.250 | 61 | 26.437 | 24.750 | 5.34 | 9.93 | 7 |
| J150SX20BTC | 3605 | 76.250 | 61 | 31.437 | 24.750 | 5.34 | 9.93 | 7 |
| J150SX20RTA | 2963 | 76.250 | 61 | 23.937 | 24.750 | 5.34 | 9.93 | 7 |
| J150SX20RTB | 3263 | 76.250 | 61 | 26.437 | 24.750 | 5.34 | 9.93 | 7 |
| J150SX20RTC | 3605 | 76.250 | 61 | 31.437 | 24.750 | 5.34 | 9.93 | 7 |
| J165SX20BTA | 2963 | 76.250 | 61 | 23.937 | 24.750 | 5.34 | 9.93 | 7 |
| J165SX20BTB | 3263 | 76.250 | 61 | 26.437 | 24.750 | 5.34 | 9.93 | 7 |
| J165SX20BTC | 3605 | 76.250 | 61 | 31.437 | 24.750 | 5.34 | 9.93 | 7 |
| J165SX20RTA | 2963 | 76.250 | 61 | 23.937 | 24.750 | 5.34 | 9.93 | 7 |
| J165SX20RTB | 3263 | 76.250 | 61 | 26.437 | 24.750 | 5.34 | 9.93 | 7 |
| J165SX20RTC | 3605 | 76.250 | 61 | 31.437 | 24.750 | 5.34 | 9.93 | 7 |
*Gunnebo Johnson Design Factor is 4 to 1, with some exceptions;
45 Ton models 3.6 to 1
60 Ton models 3.7 to 1
325 Ton models 3.7 to 1








