Thern Vertical Lead Block

Thern Vertical Lead Blocks offer a secure and easy way to change the direction of a winch rope and are commonly used in applications where the winch is awkwardly positioned or a line needs to feed around/over/under an obstacle.

Offering rope capacities up to 1/2", the Thern lead block meets even heavy-duty lifting and pulling applications.

Stay confident when not under load- with many other pulley blocks the rope can easily slip out and cause an accident, with the Thern Lead Block the rope is kept in the pulley by 'Cable Keepers' on the top and sides of the sheave.

• Up to 7000 lbs Line Load
• Cable Keepers on Top and Sides of Sheave
• Five Sizes for Different Rope Diameters
• Sealed Needle Roller Bearing with Grease Fitting
• Durable Powder Coat Finish
• Design in Accordance with ASME B30.26
• Two Year Warranty

• VLB-G25 — for 1/4″ Rope
• VLB-G31 — for 5/16″ Rope
• VLB-G38 — for 3/8″ Rope
• VLB-G44 — for 7/16″ Rope
• VLB-G50 — for 1/2″ Rope

Specifications by Model

MODEL NUMBER	SHEAVE OUTER DIAMETER (INCHES)	ROPE DIAMETER (INCHES)	TOTAL WORKING LOAD LIMIT. R (LBS)	LINE LOAD LIMIT. L (LBS)
VLB-G25	4 1/2 (114 mm)	1/4 (6 mm)	4000 (1814 kg)	2000 (907 kg)
VLB-G31	6 (152 mm)	5/16 (8 mm)	6000 (2722 kg)	3000 (1361 kg)
VLB-G38	7 (178 mm)	3/8 (10 mm)	9600 (4354 kg)	4800 (2177 kg)
VLB-G44	8 (203 mm)	7/16 (11 mm)	11600 (5262 kg)	5800 (2631 kg)
VLB-G50	9 (229 mm)	1/2 (13 mm)	14000 (6350 kg)	7000 (3175 kg)

Factor = Total Load/Line Load

ANGLE (DEGREES)	FACTOR
0	2.00
10	1.99
20	1.97
30	1.93
40	1.87
45	1.84
50	1.81
60	1.73
70	1.64
80	1.53
90	1.41
100	1.29
110	1.15
120	1.00
130	0.84
135	0.76
140	0.68
150	0.52
160	0.35
170	0.17
180	0.00

Mounting Fasteners

VLB-G25	7/16 Inch Grade 5 min or M12 grade 8.8 min
VLB-G31	1/2 Inch Grade 5 min or M12 grade 8.8 min
VLB-G38	5/8 Inch Grade 5 min or M16 grade 8.8 min
VLB-G44	3/4 Inch Grade 5 min or M20 grade 8.8 min
VLB-G50	3/4 Inch Grade 5 min or M20 grade 8.8 min