GENERAL PURPOSE WIRE ROPE

The diameter of a drum or pulley should not be less than 500 times the diameter of the outside wire of the rope. The groove radius of a pulley should be within the range 5% to 15% larger than D/2 with the optimum radius 10% greater than D/2. The recommended radius of a drum groove is 6% greater than D/2 - where D is the nominal rope diameter. The bottom of the grooves should be arcs of circles equal in length to one-third of the circumference of the rope. The depth of a groove in a pully should be at least equal to one and a half times the rope diameter and the groove in a drum should not be less than one-third of the rope diameter. The angle of flare between the sides of the sheaves should be approximately 52° but should be greater if the fleet angle exceeds 1.5°. The clearance between neighbouring turns of rope on a drum should not be
less than:

•  1.6mm for ropes up to 13mm diameter
•  2.4mm for ropes over 13mm and up to 28mm diameter
•  3.2mm for ropes over 28mm and up to 38mm diameter

In terms of rope diameters the sizes of drums and pulleys would be:

Rope construction                                               Minimum round strand pulley diameter
6 x 19 (9/9/1)                                                         40 x D
6 x 19 (12/6+6F/1)                                                33 x D
6 x 36 (14/7&7/7/1)                                               29 x D

Multi-Strand
17 x 7 18D
34 x 7 18D

Always refer to the wire rope manufacturers
own recommendations.