20.8.1 Marking
In addition to the marking required by the applicable national legislation and standard being worked to the following information should be permanently and legibly marked on each eyebolt:
Identification mark. (If the manufacturer has not provided a unique serial number then it is the responsibility of the user to add the identification mark to identify the equipment with the inspection and examination reports).
SWL.
Quality i.e. grade.
Screw thread type.
Year manufacture
Unique trademark or symbol identifying the manufacturer
The marking shall be either:
On the side of the link away from the weld in the case of eyebolts with link; or
On the raised flat areas provided or similar positions in the absence of flat areas in the case of collar and dynamo eyebolts.
Additionally, in all cases where the designated area is insufficient the periphery of the collar may be used if it can be done without damage to the machined face.
The symbols should be as large as possible but in any case not less than 3mm high and in no case should the mechanical properties of the item be impaired.
Different forms of marking are to be found on the various types of eyebolts shown according to the date of issue. To avoid confusion and remove any anomalies, all existing eyebolts should be marked with any additional information necessary to bring them in line with the following:
Identification mark - each eyebolt should be marked so as to identify it with its historical record.
WLL marking - it is a requirement that each eyebolt should be marked with its axial WLL., e.g. WLL 1.6t.
Quality marking - the material quality mark should be clearly shown. The quality mark may appear as raised figures in the forging on the side of the crown of the eye.
Screw thread marking - Each eyebolt should be legibly and permanently marked with one of the following thread identifications as appropriate:
‘M’ to denote ISO metric threads, coarse series, including the accepted metric thread diameter designation, e.g. M12;
‘BSW’ to denote BS Whitworth threads, including the accepted BSW thread diameter designation, e.g. ½BSW;
‘UNC’ to denote unified coarse threads, including the accepted UNC thread diameter designation, e.g. ½UNC.”
It is therefore recommended that, to avoid the possibility of mismatch, eyebolts of all types and standards and also any tapped holes not so identified should be marked with this information as soon as possible.
These screw thread markings fulfil the recommendations that eyebolts and tapped holes are marked with their respective thread diameters and form, as a means to minimise the dangers of mismatch.