20 inch

Key to one sheave J-Block Model Numbers

J

3

S

10

B

T

A

Shorty “J” Crane Block

Safe Working Limit-Tons

Number of Sheaves

Single

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	T	U
		Overall	Net	Thick-		Throat Opening	Hook	Hook	Deadend	Hole
		Length	Length	ness	Width	w/Latch	Thick.	Width	Thick.	Dia.
J25S20BTA	434	49.750	40.875	8.562	24.750	3.28	3.750	3	1.50	2.06
J25S20BTB	734	49.750	40.875	11.437	24.750	3.28	3.750	3	1.50	2.06
J25S20BTC	1078	49.750	40.875	16.437	24.750	3.28	3.750	3	1.50	2.06
J25S20RTA	434	49.750	40.875	8.562	24.750	3.28	3.750	3	1.50	2.06
J25S20RTB	734	49.750	40.875	11.437	24.750	3.28	3.750	3	1.50	2.06
J25S20RTC	1078	49.750	40.875	16.437	24.750	3.28	3.750	3	1.50	2.06
J30S20BTA	448	50.250	41.375	8.562	24.750	3.28	3.50	3	1.50	2.06
J30S20BTB	748	50.250	41.375	11.437	24.750	3.28	3.50	3	1.50	2.06
J30S20BTC	1092	50.250	41.375	16.437	24.750	3.28	3.50	3	1.50	2.06
J30S20RTA	448	50.250	41.375	8.562	24.750	3.28	3.50	3	1.50	2.06
J30S20RTB	748	50.250	41.375	11.437	24.750	3.28	3.50	3	1.50	2.06
J30S20RTC	1092	50.250	41.375	16.437	24.750	3.28	3.50	3	1.50	2.06
J35S20BTA	528	54.750	44.625	8.562	24.750	3.27	4.250	3.38	1.75	2.28
J35S20BTB	828	54.750	44.625	11.437	24.750	3.27	4.250	3.38	1.75	2.28
J35S20BTC	1172	54.750	44.625	16.437	24.750	3.27	4.250	3.38	1.75	2.28
J35S20RTA	528	54.750	44.625	8.562	24.750	3.27	4.250	3.38	1.75	2.28
J35S20RTB	828	54.750	44.625	11.437	24.750	3.27	4.250	3.38	1.75	2.28
J35S20RTC	1172	54.750	44.625	16.437	24.750	3.27	4.250	3.38	1.75	2.28
J40S20BTA	648	59	46.875	9.437	24.750	3.27	4.250	3.38	1.75	2.28
J40S20BTB	947	59	46.875	12.187	24.750	3.27	4.250	3.38	1.75	2.28
J40S20BTC	1291	59	46.875	17.187	24.750	3.27	4.250	3.38	1.75	2.28
J40S20RTA	648	59	46.875	9.437	24.750	3.27	4.250	3.38	1.75	2.28
J40S20RTB	947	59	46.875	12.187	24.750	3.27	4.250	3.38	1.75	2.28
J40S20RTC	1291	59	46.875	17.187	24.750	3.27	4.250	3.38	1.75	2.28

*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