LIFTINGSAFETY
Yoke 551 Series Super Snatch Block with Shackle - 20 tonne

Yoke 551 Series Super Snatch Block with Shackle - 20 tonne

Shackle suspension pulley block with built in RFID chip. To suit wire line sizes between 25 and 29mm.

Model: 

8-551-xx / YSSB-5523

Yoke 551 Series Super Snatch Block with Shackle - 20 tonne

8-551 Snatch Block with Shackle
  • YOKE Super Snatch Blocks are manufactured of the highest quality tensile steel.
  • Available for 20 tonnes, for wire rope sizes 25mm to 29mm.
  • Certified by ABS, UKCA Type Approval.
  • Part number, wire rope size and working load limit are marked on each block.
  • Permanent batch codes link to test certificates for easy traceability.
  • Supplied with bronze bushings and pressure lube fittings.
  • Meets or exceeds all requirements of ASME B30.26.
  • Safety factor 4:1
  • Fatigue rated
  • Supplied with a Certificate of Conformity
  • Factory fitted with an RFID chip for serial and certificate traceability.
  • Sheave groove bottom is hardened to 35 Rc to maximise durability.
  • Closed die forged steel sheave.

Specifications

Item No. Sheave Dia. (inch) Bearing Type Wire Rope Size (mm) Working Load Limit (tonnes) Weight (lbs) Weight (kg)
8-551-20 8 Bronze Bushing 25-29 20 92 42
8-551-2010 10 Bronze Bushing 25-29 20 119 54
8-551-2012-25 12 Bronze Bushing 25 20 139 63
8-551-2012-29 12 Bronze Bushing 29 20 139 63

*Minimum Ultimate Load is 4 times the Working Load Limit.

Dimensions

Item No. B (mm) E (mm) F (mm) G (mm) L (mm) R (mm) T (mm)
8-551-20 93 146 55 216 671 616 51
8-551-2010 93 146 55 280 778 723 51
8-551-2012-25 93 146 55 330 833 778 51
8-551-2012-29 93 146 55 330 833 778 51
Dimensional Drawing

Loads on Blocks

Angle Factor Multipliers

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 Angle Factor
0 2 100 1.29
10 1.99 110 1.15
20 1.97 120 1
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
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

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 16 2.1
25 6.6 14 1.5
20 3.8 12 1.1
18 2.9 - -
Part N° Sheave Dia. (inch) Bearing Type Wire Rope Size (mm) Working Load Limit (tonnes) Weight (kg) Unit Price Quantity
5523-T28472 8 Bronze Bushing 25-29 20 42 £  1875.00
5523-T28473 10 Bronze Bushing 25-29 20 54 £  2100.00
5523-T28474 12 Bronze Bushing 25 20 63 Quote Required
5523-T28475 12 Bronze Bushing 29 20 63 £  2650.00
   
Description

+
  • YOKE Super Snatch Blocks are manufactured of the highest quality tensile steel.
  • Available for 20 tonnes, for wire rope sizes 25mm to 29mm.
  • Certified by ABS, UKCA Type Approval.
  • Part number, wire rope size and working load limit are marked on each block.
  • Permanent batch codes link to test certificates for easy traceability.
  • Supplied with bronze bushings and pressure lube fittings.
  • Meets or exceeds all requirements of ASME B30.26.
  • Safety factor 4:1
  • Fatigue rated
  • Supplied with a Certificate of Conformity
  • Factory fitted with an RFID chip for serial and certificate traceability.
  • Sheave groove bottom is hardened to 35 Rc to maximise durability.
  • Closed die forged steel sheave.

Specifications

Item No. Sheave Dia. (inch) Bearing Type Wire Rope Size (mm) Working Load Limit (tonnes) Weight (lbs) Weight (kg)
8-551-20 8 Bronze Bushing 25-29 20 92 42
8-551-2010 10 Bronze Bushing 25-29 20 119 54
8-551-2012-25 12 Bronze Bushing 25 20 139 63
8-551-2012-29 12 Bronze Bushing 29 20 139 63

*Minimum Ultimate Load is 4 times the Working Load Limit.

Dimensions

Item No. B (mm) E (mm) F (mm) G (mm) L (mm) R (mm) T (mm)
8-551-20 93 146 55 216 671 616 51
8-551-2010 93 146 55 280 778 723 51
8-551-2012-25 93 146 55 330 833 778 51
8-551-2012-29 93 146 55 330 833 778 51
Dimensional Drawing
Load on Blocks

+

Loads on Blocks

Angle Factor Multipliers

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 Angle Factor
0 2 100 1.29
10 1.99 110 1.15
20 1.97 120 1
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
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

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

+

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