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Shaft Diameter vs Key Sizes Design Recommendations
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Recommended ANSI Standard Keys and Keyseats Design per. ANSI B17.1
Recommended uniform relationship between shaft diameter and key sizes for parallel and taper keys. All sizes are in inch units.
Nominal
Shaft Diameter |
Nominal
Key Size |
Normal
Keyseat Depth |
||||
---|---|---|---|---|---|---|
Over
|
To (Incl.)
|
Width, W
|
Height, H
|
H/2
|
||
Square
|
Rectangular
|
Square
|
Rectangular
|
|||
5/16
|
7/16
|
3/32
|
3/32
|
…
|
3/64
|
…
|
7/16
|
9/16
|
1/8
|
1/8
|
3/32
|
1/16
|
3/64
|
9/16
|
7/8
|
3/16
|
3/16
|
1/8
|
3/32
|
1/16
|
7/8
|
1-1/4
|
1/4
|
1/4
|
3/16
|
1/8
|
3/32
|
1-1/4
|
1-3/8
|
5/16
|
5/16
|
1/4
|
5/32
|
1/8
|
1-3/8
|
1-3/4
|
3/8
|
3/8
|
1/4
|
3/16
|
1/8
|
1-3/4
|
2-1/4
|
1/2
|
1/2
|
3/8
|
1/4
|
3/16
|
2-1/4
|
2-3/4
|
5/8
|
5/8
|
7/16
|
5/16
|
7/32
|
2-3/4
|
3-1/4
|
3/4
|
3/4
|
1/2
|
3/8
|
1/4
|
3-1/4
|
3-3/4
|
7/8
|
7/8
|
5/8
|
7/16
|
5/16
|
3-3/4
|
4-1/2
|
1
|
1
|
3/4
|
1/2
|
3/8
|
4-1/2
|
5-1/2
|
1-1/4
|
1-1/4
|
7/8
|
5/8
|
7/16
|
5-1/2
|
6-1/2
|
1-1/2
|
1-1/2
|
1
|
3/4
|
1/2
|
Square Keys preferred for shaft diameters
above this line; rectangular keys, below |
||||||
6-1/2
|
7-1/2
|
1-3/4
|
1-3/4
|
1-1/2 a
|
7/8
|
3/4
|
7-1/2
|
9
|
2
|
2
|
1-1/2
|
1
|
3/4
|
9
|
11
|
2-1/2
|
2-1/2
|
1-3/4
|
1-1/4
|
7/8
|
a Some key standards show 1-1/4 inches, preferred height is 1-1/2 inches.