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Chandlery Information

Thimble Dimensions and Compatible Shackles

Good quality, heavy duty galvanised and stainless steel thimbles can present a challenge when it comes to finding a suitable size shackle.

This is especially true with galvanised thimbles for larger diameter ropes.

Commercial Pattern shackles are a tempting solution because they are usually capacious enough to fit over large thimbles.
However the risk of failure is considerable and the galvanised versions will suffer very quickly from corrosion.

Selecting a rated shackle is highly recommended because they are not only much stronger than commercial pattern shackles, but also have the reassurance of a manufacturer guaranteed break load.
e.g.

Green Pin Shackles

Jimmy Green Galvanised Pin Bow Shackles

Jimmy Green Galvanised Pin D Shackles

All these shackles derive extra strength from three important design factors:

  • Increased pin diameter size for size, compared with the crown diameter
  • Short pin = narrow jaw width
  • Small overall circumference

The second two factors mean that a strong enough shackle will not necessarily fit over/around the next attachment/connection point e.g. a swivel, thimble, another shackle

Consequently, you may need more than one shackle to bridge the gap

Green pin shackle properties

The tables below chart the inside dimensions of the galvanised and stainless steel thimbles, together with the overall thickness.

The Jimmy Green Team have physically checked the Green Pin shackles (Yellow Pin and and Jimmy Green Galvanised Pin are the same) on each size of thimble and tabled the smallest size shackle that will both fit over, and sit comfortably on each size of thimble.

Thimble dimensions diagram

Galvanised Thimbles – Specifications and Compatible Shackle Size
ThimbleLWDShackle
6mm32mm21mm11mm5mm
8mm34mm24mm14mm9mm
10mm39mm26mm16mm10mm
12mm47mm33mm18mm11mm
14mm47mm33mm18mm11mm
16mm63mm42mm23mm16mm
18mm70mm45mm25mm19mm
20mm93mm70mm34mm22mm
24mm110mm74mm35mm22mm
28mm120mm80mm42mm25mm
32mm160mm115mm48mm25mm

Thimble = thimble size by rope diameter
L = approximate internal length
W = internal width at the widest point
D = thickness
Shackle = the smallest size shackle (Green, Yellow or Jimmy Green Galvanised Pin) that will fit over, and sit comfortably on each size thimble
e.g. a 6mm thimble requires a 5mm Shackle with 6mm Pin

Thimble dimensions diagram

Stainless steel thimbles are smaller size for size than galvanised.

Stainless Steel Thimbles – Specifications and Compatible Shackle Size
ThimbleLWDShackle
8mm34mm21mm11mm5mm
10mm45mm27mm15mm7mm
12mm47mm31mm18mm9mm
14mm55mm34mm20mm11mm
16mm65mm40mm24mm16mm
18mm73mm46mm26mm16mm
20mm77mm45mm28mm16mm
24mm83mm52mm35mm19mm
28mm135mm80mm40mm22mm
32mm170mm90mm42mm25mm

Thimble = thimble size by rope diameter
L = approximate internal length
W = internal width at the widest point
D = thickness
Shackle = the smallest size shackle (Green, Yellow or Jimmy Green Galvanised Pin) that will fit over, and sit comfortably on each size thimble
e.g. an 8mm thimble requires a 5mm Shackle with 6mm Pin

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