18 inch

Four-Sheave-J-Block

Key to four sheave J-Block Model Numbers

J 15 Q 10 B T A
Shorty “J” Crane Block Safe Working Limit-Tons

Number of Sheaves

Q=4
Quadruple

Sheave Size – Nom. O.D.

Sheave Bearing:

B = Bronze Bushed
R= Roller Bearing

Hook-Thrust Bearing

Cheek Weights:
A = No wts.
AB = Med. wts.
B = Std. wts.
C = X-Heavy wts.


MODEL WT. A B E F H J K
Overall Net Thick- Width Throat Opening Hook Hook
Length Length ness w/ Latch Thick Width
J40Q18BTA 916 49.375 45.125 15 22.75 3.27 4.25 3.38
J40Q18BTB 1142 49.375 45.125 17.375 22.75 3.27 4.25 3.38
J40Q18BTC 1280 49.375 45.125 19.125 22.75 3.27 4.25 3.38
J40Q18RTA 916 49.375 45.125 15 22.75 3.27 4.25 3.38
J40Q18RTB 1142 49.375 45.125 17.375 22.75 3.27 4.25 3.38
J40Q18RTC 1280 49.375 45.125 19.125 22.75

3.27

4.25 3.38
J45Q18BTA 916 49.375 45.125 15 22.75 3.27 4.25 3.38
J45Q18BTB 1142 49.375 45.125 17.375 22.75 3.27 4.25 3.38
J45Q18BTC 1280 49.375 45.125 19.125 22.75 3.27 4.25 3.38
J45Q18RTA 916 49.375 45.125 15 22.75 3.27 4.25 3.38
J45Q18RTB 1142 49.375 45.125 17.375 22.75 3.27 4.25 3.38
J45Q18RTC 1280 49.375 45.125 19.125 22.75 3.27 4.25 3.38
J55Q18BTA 991 53.750 47.625 14.875 22.75 4.63 6.13 4.00
J55Q18BTB 1217 53.750 47.625 17.375 22.75 4.63 6.13 4.00
J55Q18BTC 1355 53.750 47.625 19.125 22.75 4.63 6.13 4.00
J55Q18RTA 991 53.750 47.625 14.875 22.75 4.63 6.13 4.00
J55Q18RTB 1217 53.750 47.625 17.375 22.75 4.63 6.13 4.00
J55Q18RTC 1355 53.750 47.625 19.125 22.75 4.63 6.13 4.00
J60Q18BTA 991 53.750 47.625 14.875 22.75 4.63 6.13 4.00
J60Q18BTB 1217 53.750 47.625 17.375 22.75 4.63 6.13 4.00
J60Q18BTC 1355 53.750 47.625 19.125 22.75 4.63 6.13 4.00
J60Q18RTA 991 53.750 47.625 14.875 22.75 4.63 6.13 4.00
J60Q18RTB 1217 53.750 47.625 17.375 22.75 4.63 6.13 4.00
J60Q18RTC 1355 53.750 47.625 19.125 22.75 4.63 6.13 4.00
J70Q18BTA 1038 54 47.750 14.875 22.75 4.36 6.25 4.50
J70Q18BTB 1264 54 47.750 17.375 22.75 4.36 6.25 4.50
J70Q18BTC 1402 54 47.750 19.125 22.75 4.36 6.25 4.50
J70Q18RTA 1038 54 47.750 14.875 22.75 4.36 6.25 4.50
J70Q18RTB 1264 54 47.750 17.375 22.75 4.36 6.25 4.50
J70Q18RTC 1402 54 47.750 19.125 22.75 4.36 6.25 4.50
J75Q18BTA 1164 58 51 15 22.75 4.75 6.75 4.75
J75Q18BTB 1390 58 51 17.375 22.75 4.75 6.75 4.75
J75Q18BTC 1528 58 51 19.125 22.75 4.75 6.75 4.75
J75Q18RTA 1164 58 51 15 22.75 4.75 6.75 4.75
J75Q18RTB 1390 58 51 17.375 22.75 4.75 6.75 4.75
J75Q18RTC 1528 58 51 19.125 22.75 4.75 6.75 4.75
J80Q18BTA 1164 58 51 15 22.75 4.75 6.75 4.75
J80Q18BTB 1390 58 51 17.375 22.75 4.75 6.75 4.75
J80Q18BTC 1528 58 51 19.125 22.75 4.75 6.75 4.75
J80Q18RTA 1164 58 51 15 22.75 4.75 6.75 4.75
J80Q18RTB 1390 58 51 17.375 22.75 4.75 6.75 4.75
J80Q18RTC 1528 58 51 19.125 22.75 4.75 6.75 4.75


Dead End Chart

Wire Rope Size T U For Pin Size
7/16″ thru 5/8″ 1 1.28 1-1/4
3/4″ thru 1″ 1.25 1.65 1-5/8
1-1/8″ thru 1-3/8″ 1.75 2.51 2-1/2

*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