Description
Reviews
Features
Specification
Downloads

 

Our Light Snatch Blocks with Shackles from Yoke are high-performance and are capable of lifting up to 8t, safely - dependent on the variation chosen.

 

Availalbe in 4 sheave diameters (see options via dropdown menu), they are particularly suited to applications in oilfields and offshore environments.

 

Featuring part number, wire rope size and WLL marked on each unit, they are fatigue rated to 20,000 cycles at 1.5x the working load limit, as well as designed with a safety factor of 4:1.

  • Capacity: 2t / 4t / 8t
  • Wire rope size: 8-10mm / 10-13mm / 16-19mm
  • Sheave diameter: 3" / 4.5" / 6" / 8"
  • Bronze bushing and grease fitting
  • ASME B30.26-2010
  • Safety factor: 4:1
  • Forged and Super also available

DIMENSIONAL SPECIFICATIONS

Part Code

WLL
tonnes

Sheave Dia.
mm

Wire Rope
Size
mm

a
mm
b
mm
e
mm
f
mm
g
mm
k
mm
l
mm
r
mm

Mass
kg

8-501-02

2.0

76

8-10 35 30 64 11 75 150 228 217 3.8

8-501-04

4.0

114

10-13 64 50 79 19 107 243 356

336

6.2

8-501-08

8.0

152

16-19 87 76 104 32 152 320 484 452

13.2

8-501-0808

8.0

203

16-19 87 76 104 32 220 333 558 526

18.2

8-541-12

12.0

152

19-22 78 80 134 44 167 359 540 496

24.8

8-541-15

15.0

203

19-22 78 80 134 44 220 355 589 545

29.6

8-541-1510

15.0

254

19-22 78 80 134 44 280 423 714 670

42.7

8-501-1512

15.0

305

19-22 78 80 134 44 330 428 770 726

52.8

8-551-20

20.0

203

25-29 109 93 150 55 216 433 671 616

41.6

8-551-2010

20.0

254

25-29 109 93 150 55 280 481 778 723

52.4

8-551-2012-29

20.0

305

25-29 109 93 150 55 330 485 883 778

62.8

Part Code

WLL
tonnes

Sheave Dia.
inches

Wire Rope
Size
inch

a
inch
b
inch
e
inch
f
inch
g
inch
k
inch
l
inch
r
inch

Mass
lbs.

8-501-02

2 3 5/16 - 3/8 1.38 1.18 2.52 0.43 2.95 5.91 8.96 8.53 4.4

8-501-04

4 4-1/2 3/8 - 1/2 2.52 1.97 3.11 0.75 4.21 9.57 14.02 13.27 13.0

8-501-08

8 6 5/8 - 3/4 3.43 2.99 4.09 1.26 5.98 12.60 19.06 17.80 28.7

8-501-0808

8 8 5/8 - 3/4 3.43 2.99 4.09 1.26 8.66 13.10 21.90 20.64 43.0

8-541-12

12 6 3/4 - 7/8 3.07 3.15 5.28 1.73 6.57 14.13 21.26 19.63 53.6

8-541-15

15 8 3/4 - 7/8 3.07 3.15 5.28 1.73 8.66 13.99 23.19 21.46 65.1

8-541-1510

15 10 3/4 - 7/8 3.07 3.15 5.28 1.73 11.00 16.70 28.10 26.37 94.8

8-501-1512

15 12 3/4 - 7/8 3.07 3.15 5.28 1.73 13.00 16.80 30.30 28.57 117.9

8-551-20

20 8 1 - 1-1/8 4.29 3.66 5.91 2.17 8.50 17.05 26.42 24.25 90.8

8-551-2010

20 10 1 - 1-1/8 4.29 3.66 5.91 2.17 11.00 18.90 30.60 28.46 119.0

8-551-2012-29

20 12 1 - 1-1/8 4.29 3.66 5.91 2.17 13.00 19.10 32.80 30.63 137.8

LOADS ON BLOCKS

Angle Factor Mutipliers

The Working Load Limit (WLL) for Yoke Group blocks indicates the maximum load that should be exerted on the block and its connecting fitting. This total load value may be different from the weight being lifted or pulled by a hoisting system. It is necessary to determine the total load being imposed on each block in the system to properly determine the rated capacity block to be used. A single sheave block used to change load line direction can be subjected to total loads greatly different from the weight being lifted or pulled. The total load value varies with the angle between the incoming and departing lines to the block. The following chart indicates the factor to be multiplied by the line pull to obtain the total load on the block.

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

SHEAVE SIZE AND WIRE ROPE STRENGTH

Ratio A

Strength Efficiency Compared
to Catalogue Strength in %

Ratio A

Strength Efficiency Compared
to Catalogue Strength in %

40 95 8 83
30 93 6 79
20 91 4 75
15 89 2 65
10 86 1 50

Ratio A = Sheave Diameter ÷ Rope Diameter

Strength Efficiency

Bending wire rope reduces its strength. To account for the effect of bend radius on wire rope strength when selecting a sheave, use the table above.

Ratio B

Relative Fatigue
Bending Life

Ratio B

Relative Fatigue
Bending Life

30 10.0 16 2.1
25 6.6 14 1.5
20 3.8 12 1.1
18 2.9 - -