Groove Radius Groove Radius Groove Radius Groove Radius
Nominal Rope Diameter Nominal Rope Diameter New New Worn Worn
1 inches 2 mm 3 inches 4 mm 5 inches 6 mm
1/4 6.4 .135 3.43 .129 3.28
5/16 8.0 .167 4.24 .160 4.06
3/8 9.5 .201 5.11 .190 4.83
7/16 11 .234 5.94 .220 5.59
1/2 13 .271 6.88 .256 6.50
9/16 14.5 .303 7.70 .288 7.32
5/8 16 .334 8.48 .320 8.13
3/4 19 .401 10.19 .380 9.65
7/8 22 .468 11.89 .440 11.18
1 26 .543 13.79 .513 13.03
1-1/8 29 .605 15.37 .577 14.66
1-1/4 32 .669 16.99 .639 16.23
1-3/8 35 .736 18.69 .699 17.75
1-1/2 38 .803 20.40 .759 19.28
1-5/8 42 .876 22.25 .833 21.16
1-3/4 45 .939 23.85 .897 22.78
1-7/8 48 1.003 25.48 .959 24.36
2 52 1.085 27.56 1.025 26.04
2-1/8 54 1.137 28.88 1.079 27.41
2-1/4 58 1.210 30.73 1.153 29.29
2-3/8 60 1.271 32.28 1.199 30.45
2-1/2 64 1.338 33.99 1.279 32.49
2-5/8 67 1.404 35.66 1.339 34.01
2-3/4 71 1.481 37.62 1.409 35.79
2-7/8 74 1.544 39.22 1.473 37.41
3 77 1.607 40.82 1.538 39.07
3-1/8 80 1.664 42.27 1.598 40.59
3-1/4 83 1.731 43.97 1.658 42.11
3-3/8 87 1.807 45.90 1.730 43.94
3-1/2 90 1.869 47.47 1.794 45.57
3-3/4 96 1.997 50.72 1.918 48.72
4 103 2.139 54.33 2.050 52.07
4-1/4 109 2.264 57.51 2.178 55.32
4-1/2 115 2.396 60.86 2.298 58.37
4-3/4 122 2.534 64.36 2.434 61.82
5 128 2.663 67.64 2.557 64.95
5-1/4 135 2.804 71.22 2.691 68.35
5-1/2 141 2.929 74.40 2.817 71.55
5-3/4 148 3.074 78.08 2.947 74.85
6 154 3.198 81.23 3.075 78.11

* Values
given are applicable to grooves in sheaves and drums; they are
not generally suitable for pitch design since this may involve
other factors.

Further, the dimensions do not apply to traction-type elevators; in this
circumstance, drum-and sheave-groove tolerances should conform
to the elevator manufacturer’s specifications.

Modern drum design embraces extensive considerations beyond the scope
of this publication. It should also be noted that drum grooves
are now produced with a number of oversize dimensions and pitches
applicable to certain service requirements.