Couplings • Hub Keyway Tolerances & Standard Fillet Radii
All Types (Page 1 of 1)
Nominal Bore Key Size Keyway Size
Over Thru Width x Height Suggested Chamfer for Standard Filleted Keyways 45°(+.005 – .000) Width x Depth Tolerance Optional Fillet Radii
Width Depth Standard † (±.010) Alternate (±.010)
.4375 .5625 .125 x .125 .031 (1/32) .125 x .062 +.0020–.0000 +.010 to +.020 .016 (1/64) ....
.5625 .875 .1875 x .1875 .031 (1/32) .1875 x .094 +.0020–.0000 +.010 to +.020 .016 (1/64) .031 (1/32)
.875 1.250 .250 x .250 .031 (1/32) .250 x .125 +.0020–.0000 +.010 to +.020 .016 (1/64) .031 (1/32)
1.250 1.375 .3125 x .3125 .047 (3/64) .3125 x .156 +.0020–.0000 +.010 to +.020 .031 (1/32) ....
1.375 1.750 2.250 2.750 3.250 1.750 2.250 2.750 3.250 3.750 .375 x .375 .500 x .500 .625 x .625 .750 x .750 .875 x .875 .047 (3/64) .047 (3/64) .078 (5/64) .078 (5/64) .078 (5/64) Broached.375 x .500 x .625 x .750 x .875 x .188 .250 .312 .375 .438 +.0025–.0000 +.0025–.0000 +.0030–.0000 +.0030–.0000 +.0030–.0000 +.010 to +.020 +.010 to +.020 +.010 to +.020 +.010 to +.020 +.010 to +.020 .031 (1/32) .031 (1/32) .062 (1/16) .062 (1/16) .062 (1/16) .062 (1/16) .062 (1/16) .031 (1/32) .031 (1/32) .031 (1/32)
3.750 4.500 1.000 x 1.000 .078 (5/64) 1.000 x .500 +.0030–.0000 +.010 to +.020 .062 (1/16) ....
4.500 5.500 1.250 x 1.250 .156 (5/32) 1.250 x .625 +.0035–.0000 +.010 to +.020 .125 (1/8) .062 (1/16)
5.500 6.500 1.500 x 1.500 .156 (5/32) 1.500 x .750 +.0035–.0000 +.010 to +.020 .125 (1/8) .062 (1/16)
6.500 7.500 1.750 x 1.500 .156 (5/32) 1.750 x .750 +.0040–.0000 +.010 to +.020 .125 (1/8) ....
7.500 9.000 2.000 x 1.500 .156 (5/32) 2.000 x .750 +.0040–.0000 +.010 to +.020 .125 (1/8) ....
9.000 11.000 13.000 15.000 18.000 22.000 26.000 11.000 13.000 15.000 18.000 22.000 26.000 30.000 2.500 x 1.750 3.000 x 2.000 3.500 x 2.500 4.000 x 3.000 5.000 x 3.500 6.000 x 4.000 7.000 x 5.000 .156 (5/32) .219 (7/32) .219 (7/32) .281 (9/32) .281 (9/32) .406 (13/32) .406 (13/32) Keyseated 2.500 x 3.000 x 3.500 x 4.000 x 5.000 x 6.000 x 7.000 x .875 1.000 1.250 1.500 1.750 2.000 2.500 +.0045–.0000 +.0045–.0000 +.0050–.0000 +.0050–.0000 +.0060–.0000 +.0060–.0000 +.0060–.0000 +.010 to +.020 +.010 to +.020 +.010 to +.020 +.010 to +.020 +.010 to +.020 +.010 to +.020 +.010 to +.020 .125 (1/8) .188 (3/16) .188 (3/16) .250 (1/4) .250 (1/4) .375 (3/8) .375 (3/8) .... .... .... .... .... .... ....
Shallow keyway depths must exceed 2/3 of the full keyway depth of the square keys shown above.
†
Fillet radii comply with AGMA 9002-A86.
INTRODUCTION — The general practice in industry is to supply coupling hubs without fillet radii in the keyway corners to permit the use of standard commercial keys instead of keys with chamfered edges.
In some applications, where there is considerable vibratory or shock loading, keyways with filleted radii are used to reduce stress concentrations that may cause hub failure.
Falk will provide filleted keyways when requested (without charge), to either the Falk Standard or Alternate size listed. When “Keyway with Radii” is requested on your order, with no given size, the Falk standard will be provided. Refer to Falk for prices of filleted keyways for unlisted radii sizes.
