Roymech engineering encyclopedia

Forged Steel Dee and Bow Shackles to BS EN 13889 and ISO 2415


Current standards: BS EN 13889:2003+A1:2008 is the current UK standard for Grade 6 forged steel Dee and bow shackles for general lifting purposes. ISO 2415:2022 provides international requirements for forged Dee and bow shackles in Grades 6, 8 and 10.

Forged steel shackles are detachable lifting components used to connect slings, lifting points, hooks and other items of lifting equipment. The two principal forms are the Dee shackle and the bow shackle.

Need help selecting lifting equipment? See the Lifting Equipment Help and Selection Guide for guidance on eyebolts, Dee and bow shackles, WLL, loading direction, sling angles and choosing between current and legacy RoyMech references.

This page provides current engineering reference data for forged steel shackles, with particular emphasis on the Grade 6 shackles specified by BS EN 13889:2003+A1:2008.

Scope of BS EN 13889: The standard covers Grade 6 forged steel Dee and bow shackles for general lifting purposes with working load limits from 0.5 tonnes to 25 tonnes. It applies to shackles fitted with threaded pins.

Dee and Bow Shackle Dimensions

Forged steel Dee and bow shackle dimensions to BS EN 13889 and ISO 2415

The principal dimensions used for forged shackles are shown below.

The principal dimensional symbols are:

  • d – shackle body or bow diameter
  • D – pin diameter
  • W – inside width at the pin
  • e – eye diameter
  • S – inside length of the shackle
  • E – inside width of the bow at its widest region (bow shackle only)

BS EN 13889 Grade 6 Shackle Dimensions and WLL

The following dimensions are for Grade 6 forged steel shackles to BS EN 13889:2003+A1:2008. Dimensions are in millimetres and working load limits are in tonnes.

WLL
(t)		 Body Diameter
d (mm)		 Pin Diameter
D (mm)		 Inside Width
W (mm)		 Eye Diameter
e min. (mm)		 Inside Length S min. (mm) Bow Inside Width
E min. (mm)
Dee Bow
0.5 6.5 8 12 15.5 20 27 19
0.75 8 9.5 13.5 18.5 25 29 20
1.0 10 11 16.5 22 27 32 24
1.5 11.2 12.2 19 25 33 39 27
2.0 13.5 16 21.5 29.5 38 44 30
3.25 16.5 19 27 38 47 57 39
4.75 20 22 31.5 44 52 65 48
6.5 23 25 36.5 50 65 76 55
8.5 25.5 28 43 56 74 88 64
9.5 29 32 46.5 64 83 101 70
12 33 35 51.5 70 87 108 78
13.5 36.5 38 57 76 104 126 85
17 39.5 42 60 84 115 139 94
25 46 51 74 100 139 168 119

The values above are the principal nominal or minimum dimensions associated with the stated Grade 6 working load limits. Manufacturing tolerances also apply and should be obtained from the standard where inspection against the standard is required.

Dee Shackles

A Dee shackle has a relatively narrow body and is generally used where the load is substantially aligned with the centreline of the shackle.

The narrow configuration provides a compact connection between two lifting components, but it should not be interpreted as permitting significant side loading or spreading of the shackle body.

Bow Shackles

A bow shackle has a wider, rounded body which provides greater internal space than a Dee shackle. This can be useful where more than one sling component must be accommodated or where greater connection clearance is required.

A bow shackle is not an unrestricted multidirectional lifting point. Its larger bow provides additional connection space, but loading outside the intended direction can alter the stresses in the shackle and pin. The manufacturer's permitted loading arrangements and any required WLL reductions must be observed.

Shackle Pin Types

BS EN 13889 identifies threaded shackle pins including:

  • Type W – screwed pin with eye and collar.
  • Type X – bolt-type pin with hexagon head, hexagon nut and split cotter pin.

The appropriate pin arrangement depends upon the application. The pin supplied for the shackle forms part of the rated lifting component and should not be replaced by an ordinary bolt or an unidentified substitute.

Working Load Limit

The Working Load Limit (WLL) is the maximum load for which the shackle is rated under its specified conditions of use.

The WLL is a property of the complete identified shackle assembly. It cannot be determined reliably from body diameter, pin diameter or physical size alone.

Safety-critical component: Never assign a lifting capacity to an unidentified shackle merely by measuring its body or pin. Grade, manufacture, heat treatment, pin type, marking and condition are all relevant to its rated capacity.

BS EN 13889 and ISO 2415

BS EN 13889:2003+A1:2008 covers Grade 6 forged Dee and bow shackles with threaded pins for general lifting purposes, over the WLL range 0.5 t to 25 t.

ISO 2415:2022 has a broader international scope. It specifies forged Dee and bow shackles in Grades 6, 8 and 10 with working load limits extending from 0.5 t to 120 t.

ISO 2415 also specifies preferred dimensions intended to provide interchangeability and compatibility with other lifting components. The standard covers shackles intended for use over the temperature range −20°C to +200°C.

Do not interchange grade and WLL data: ISO 2415 associates different working load limits with Grades 6, 8 and 10. A physically similar shackle must not be assumed to have the WLL of a higher grade unless its manufacture, grade and marking establish that rating.

Selection of Shackles

Selection should consider more than the required working load limit. Important factors include:

  • required WLL;
  • Dee or bow body configuration;
  • shackle grade;
  • pin type;
  • dimensions of the components being connected;
  • loading direction;
  • number and arrangement of sling legs;
  • environment and operating temperature;
  • manufacturer's instructions and permitted loading arrangements.

Correct Loading

The load should be applied so that the shackle and pin are loaded in the manner for which they were designed. Connections should not force the body apart or impose unintended bending on the pin.

Where more than one sling leg is connected to a bow shackle, the included angle and contact position can affect the load in the shackle. The applicable manufacturer's loading instructions and reductions should therefore be checked rather than assuming the marked WLL applies to every configuration.

Inspection

Before use, shackles should be checked for conditions that could affect their safe operation, including:

  • correct and legible identification;
  • correct pin for the shackle body;
  • wear of the body or pin;
  • distortion or opening of the shackle body;
  • bent or damaged pins;
  • damaged or worn threads;
  • corrosion;
  • cracks or other surface defects;
  • evidence of unauthorised welding, heating or modification.

Shackles used for lifting should also be subject to the applicable statutory inspection and thorough-examination requirements.

Current and Legacy RoyMech Shackle Data

RoyMech retains the older BS 3032 and BS 6994 dimensional data because it remains useful when identifying, maintaining or assessing older equipment. Those datasets are kept separate from this current-standard reference.

Standard RoyMech Use
BS EN 13889:2003+A1:2008 Current UK Grade 6 forged Dee and bow shackles
ISO 2415:2022 Current international forged Dee and bow shackle reference, Grades 6, 8 and 10
BS 6994:1988 Withdrawn – retained as legacy engineering data
BS 3032:1958 Withdrawn – retained as legacy engineering data

Standard Status

At the time this page was prepared, BS EN 13889:2003+A1:2008 remains the current UK standard for Grade 6 forged steel Dee and bow shackles for general lifting purposes.

ISO 2415:2022 remains the published international standard. ISO has begun development of a replacement edition, but until that edition is published ISO 2415:2022 remains the appropriate published ISO reference.

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