12 inch

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-10D12BTA	165	28.875	26.250	6.125	16	1.91	2.53	1.93
J-10D12BTB	285	28.875	26.250	9.687	16	1.91	2.53	1.93
J-10D12BTC	435	28.875	26.250	14.187	16	1.91	2.53	1.93
J-10D12RTA	165	28.875	26.250	6.125	16	1.91	2.53	1.93
J-10D12RTB	285	28.875	26.250	9.687	16	1.91	2.53	1.93
J-10D12RTC	435	28.875	26.250	14.187	16	1.91	2.53	1.93
J-15D12BTA	170	28.875	26.250	6.125	16	1.91	2.53	1.93
J-15D12BTB	290	28.875	26.250	9.687	16	1.91	2.53	1.93
J-15D12BTC	440	28.875	26.250	14.187	16	1.91	2.53	1.93
J-15D12RTA	170	28.875	26.250	6.125	16	1.91	2.53	1.93
J-15D12RTB	290	28.875	26.250	9.687	16	1.91	2.53	1.93
J-15D12RTC	440	28.875	26.250	14.187	16	1.91	2.53	1.93
J-20D12BTA	225	34.250	30.500	6.625	16	2.80	3.00	2.38
J-20D12BTB	345	34.250	30.500	10.187	16	2.80	3.00	2.38
J-20D12BTC	500	34.250	30.500	14.687	16	2.80	3.00	2.38
J-20D12RTA	225	34.250	30.500	6.625	16	2.80	3.00	2.38
J-20D12RTB	345	34.250	30.500	10.187	16	2.80	3.00	2.38
J-20D12RTC	500	34.250	30.500	14.687	16	2.80	3.00	2.38
J-25D12BTA	225	34.250	30.500	6.625	16	2.80	3.00	2.38
J-25D12BTB	345	34.250	30.500	10.187	16	2.80	3.00	2.38
J-25D12BTC	500	34.250	30.500	14.687	16	2.80	3.00	2.38
J-25D12RTA	225	34.250	30.500	6.625	16	2.80	3.00	2.38
J-25D12RTB	345	34.250	30.500	10.187	16	2.80	3.00	2.38
J-25D12RTC	500	34.250	30.500	14.687	16	2.80	3.00	2.38

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