BS 4278:1984 pdf free download.British Standard Specification for Eyebolts for lifting purposes.
1. Scope
BS 4278 covers three types of eyebolt as follows:
(a) collar eyebolt, in the range 0.25 tonnes to
30 tonnes SWL;
(b) eyebolt with link, in the range 1.0 tonnes to
6.3 tonnes SWL;
(c) dynamo eyebolt, in the range 0.25 tonnes to
10.0 tonnes SWL.
Guidance on the selection of appropriate forgings and of SWL ratings when screwing eyebolts with imperial threads (see 4.1(b) and 4.1(c)) is given in appendix A. Recommendations on the correct selection and safe use of eyebolts are given in the foreword and appendix B.
NOTE. The titles of the publications referred to in BS 4278 are listed on the inside back cover.
2. Material
The material used in the manufacture of both the eyebolts and the links shall comply with one of the following steel specifications of BS 970 : Part 1:
080A27
080A30
080M30
070M26
3. Form and dimensions
The form and dimensions of eyebolts shall be in accordance with the following:
(a) collar eyebolts shall be as shown in figure 1 and as given in table 1 for metric threads, or table 4 for imperial threads;
(b) eyebolts with links shall be as shown in figure 2 and as given in table 2 for metric threads, or table 5 for imper4al threads;
(c) dynamo eyebolts shall be as shown in figure 3 and as given in table 3 for metric threads, or table 6 for imperial threads.
NOTE. For special applications the length of the shank (dimension H) may be increased provided that the eyebolt and shank are drop forged in one piece.
4. Screw threads
4.1 The screw threads of the shanks of the eyebolts shall
comply with the following BS 4278:
(a) Metric threads complying with BS 3643 : Part 2, coarse pitch series, tolerance class 6g. in accordance with the sizes specified in tables 1, 2 and 3 of this standard, i.e. BS 4278. For metric thread diameter 72 mm, in table 1 of this standard, a pitch of 6 mm, and a tolerance class 6g shall be used.
(b) Whitworth threads in accordance with table 4 of
BS 84 : 1956. coarse thread series, BSW, medium class.
(c) Unified threads in accordance with table 5 of
BS 1580 : Part 1: 1962, coarse series, UNC, class 2A.
NOTE. It is expected that newly designed equipment will have tapped holes to receive eyebolts screwed in accordance with (a) above. Eyebolts threaded to (b) and (c) are intended for use with imperial threaded equipment which is already in existence.
4.2 The portion of the shank at the end of the screw thread shall have a run-out and, in the case of collar eyebolts and eyebolts with link, the collar shall be recessed in accordance with dimensions J and K of tables 1 to 6.
5. Workmanship
5.1 All eyebolts. The whole of each eyebolt, including the shank, shall be cleanly drop forged in one piece and shall be free from patent defects. The underside of the collar shall be machined in true alignment at right-angles to the axis of the shank. The shank shall be screwed concentrically with the outside diameter of the collar. The thread runout and recess if any shall be smoothly radiused and free from surface irregularities.
5.2 Eyebolts with link. The link of the eyebolt with link (see figure 2, tables 2 and 5) shall be welded by one of the following methods:
(a) electric resistance butt welding;
(b) flash-butt welding;
(c) atomic hydrogen welding;
(d) inert gas shielded-arc welding.
The weld shall be smoothly finished all round and care shall be taken to avoid porosity and to ensure penetration and fusion throughout.
6. Tolerances
6.1 General. The tolerances given in 6.2 and 6.3 shall apply.
6.2 Drop forgings. The tolerances on dimensions of drop
forgings shall comply with quality F of BS 4114.
6.3 Links. The size of the material of the link shall not
differ from the nominal size (see dimension d, tables 2 and 5)
by more than ± 5 %.
7. Heat treatment
All eyebolts, after forging, and links, after welding, shall be heated to a temperature between 860 °C and 890 °C and then quenched in oil or water and tempered at a suitable
0 0
temperature between 550 C and 660 C.
8. Hardness test
8.1 General. Eyebolts shall have a Brinell hardness between
163 and 217. Either the test shall be made in accordance with BS 240: Part 1 using a 10 mm ball and a load of 3000 kg. or if another method is employed the conversion shall be made in accordance with BS 860.
8.2 Procedure. The surface on which the impression is to be made shall be obtained by filing, grinding or smooth machining.
NOTE. Suitable precautions should be taken to ensure that the surface tested is representative of the material and that its hardness is not affected by decarburization, carburization, or by the method used for the preparation of the test surface.
9. Proof loading
Each eyebolt, and eyebolt with link, after manufacture and subsequent heat treatment, shall be subjected to an axial proof load equal to at least twice the safe working load specified in tables 1, 2 or 3 or, in the case of imperial threaded eyebolts, at least twice the safe working load specified in tables 4, 5 and 6. which it shall withstand without showing any visible permanent set.
After the removal of the proof load, each eyebolt and eyebolt with link shall be thoroughly examined by a competent person and shall be accepted only if found free from visible flaw or defect.
10. Marking
10.1 General. Each eyebolt shall be legibly and permanently marked in a manner that does not impair its mechanical strength. The symbols shall be as large as possible but in any case not less than 3 mm high. In the case of collar and dynamo eyebolts, the symbols shall be marked on raised flat areas positioned on both sides of the lower parts of the eye as shown in figures 1 and 3. In the case of eyebolts with links, the symbols shall be marked on the side of the link as shown in figure 2.
NOTE. If (as for example tn the case of smaller eyebolts) the areas mentioned above provide insufficient space for marking all the requisite information, marking can be carried out on low stressed areas such as the periphery of the collar of an oyebolt.
The information given in 10.2 to 10.5 shall be marked on each eyebolt.
10.2 Quality mark. Each eyebolt shall be marked with the symbol ‘M’ enclosed in a circle. The quality mark shall be kept remote from any metric thread identification.
NOTE 1. The quality mark may, if drop forged, be on the side of the crown of the eye.
NOTE 2. In the previous issue of this standard the symbol ‘04 was used as the quality mark. Eyebolts with this marking may still be available, complying with the requirements of BS 4278.
10.3 Safe working load (axial lift). The SWL as specified in tables 1 • 2 and 3 or in the case of imperial threaded eyebolts the SWL as specified in tables 4, 5 and 6, or a lower value if required by the purchaser shall be marked on the eyebolt.
e.g. SWL 1 .6 t.
10.4 Thread identification. Each eyebolt shall be marked with one of the following thread identifications as appropriate:
(a) ‘M’ to denote ISO metric threads, coarse series, including the accepted metric thread diameter designation, e.g. M12;
(b) ‘BSW’ to denote BS Whitworth threads, including the accepted BSW thread diameter designation, e.g. % BSW.
(c) ‘UNC to denote unified coarse threads, including the accepted UNC thread diameter designation, e.g. Y2 UNC.
10.5 Distinguishing mark. Each eyebolt shall be marked with such marks or symbols as will allow identification with the certificate of test.
11. Certificate of test
The manufacturer or supplier shall provide a certificate with each consignment of eyebolts giving at least the following information for each eyebolt:
(a) distinguishing mark or symbol (see 10.5);
(b) form and size of screw thread (see clause 4 and 10.4);
(C) proof load applied (see clause 9);
(d) safe working load (see tables 1, 2, 3 or 4,5.6 and
10.3).
The certificate shall declare that each eyebolt was proof loaded in accordance with clause 9 and was subsequently examined by a competent person and that it compl;es with this standard, i.e. BS 4278. It shall state the name and address of the testing establishment and the status of the signatory.
NOTE. The certificate may be the appropriate statutory form, provided the required information is given.