18 inch

Double-Sheave-J-Block

Key to two sheave J-Block Model Numbers

J 5 D 10 B T A
Shorty “J” Crane Block Safe Working Limit-Tons

Number of Sheaves

Double

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
J-25D18BTA 460 42.375 38.625 7.750 22.750 2.80 3.00 2.38
J-25D18BTB 686 42.375 38.625 11.062 22.750 2.80 3.00 2.38
J-25D18BTC 824 42.375 38.625 12.187 22.750 2.80 3.00 2.38
J-25D18RTA 460 42.375 38.625 7.750 22.750 2.80 3.00 2.38
J-25D18RTB 686 42.375 38.625 11.062 22.750 2.80 3.00 2.38
J-25D18RTC 824 42.375 38.625 12.187 22.750 3.28 3.50 3.00
J-30D18BTA 474 42.875 39.125 7.750 22.750 3.28 3.50 3.00
J-30D18BTB 700 42.875 39.125 11.062 22.750 3.28 3.50 3.00
J-30D18BTC 838 42.875 39.125 12.187 22.750 3.28 3.50 3.00
J-30D18RTA 474 42.875 39.125 7.750 22.750 3.28 3.50 3.00
J-30D18RTB 700 42.875 39.125 11.062 22.750 3.28 3.50 3.00
J-30D18RTC 838 42.875 39.125 12.187 22.750 3.28 3.50 3.00
J-35D18BTA 530 46.625 42.375 7.750 22.750 3.27 4.25 3.38
J-35D18BTB 756 46.625 42.375 11.062 22.750 3.27 4.25 3.38
J-35D18BTC 894 46.625 42.375 12.187 22.750 3.27 4.25 3.38
J-35D18RTA 530 46.625 42.375 7.750 22.750 3.27 4.25 3.38
J-35D18RTB 756 46.625 42.375 11.062 22.750 3.27 4.25 3.38
J-35D18RTC 894 46.625 42.375 12.187 22.750 3.27 4.25 3.38
J-40D18BTA 677 49.125 44.875 8.625 22.750 3.27 4.25 3.38
J-40D18BTB 900 49.125 44.875 11.937 22.750 3.27 4.25 3.38
J-40D18BTC 1040 49.125 44.875 13.687 22.750 3.27 4.25 3.38
J-40D18RTA 677 49.125 44.875 8.625 22.750 3.27 4.25 3.38
J-40D18RTB 900 49.125 44.875 11.937 22.750 3.27 4.25 3.38
J-40D18RTC 1040 49.125 44.875 13.687 22.750 3.27 4.25 3.38


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