How to select key width?

Key width b is selected according to shaft diameter d from GB/T 1095. For example: d=20~22mm select b=6mm, d=23~30mm select b=8mm. Width tolerance generally takes N9 (shaft keyway) or J9 (hub keyway).

How to calculate keyway depth?

Keyway depth t = d - (d - t₁), where t₁ is the distance from keyway bottom to opposite shaft surface, obtained from GB/T 1095. Hub keyway depth t₁ also has corresponding standard values.

Can I generate keyway profile drawings?

Yes. After calculating keyway parameters, click the 'Generate Drawing' button. The system will automatically generate a profile measurement drawing with annotations for shaft diameter, key width, and keyway depth. The drawing can be downloaded in PNG format.

Keyway Dimension Calculator

Input shaft diameter and key type to automatically calculate key width, keyway depth, and tolerance dimensions

Parallel Key Keyway Cross-Section Diagram: Shaft Diameter d, Key Width b, Keyway Depth t

① Shaft Diameter (d)

② Key Type

③ Tolerance Grade

④ Key Length L (Optional)

Calculation Results

b = -- mm

Keyway Dimensions (GB/T 1095-2003):
Key Width b: Selected by shaft diameter d from table
Keyway Depth t: Obtained from table (approx. 0.3d~0.5d)
Hub Keyway Depth t₁: Obtained from table
Key Height h: Generally b (square) or 0.5b (thin)
Tolerance: Shaft keyway width N9, Hub keyway width J9

Keyway Dimension Calculator

About Keyway Dimension Calculator

What is a Keyway?

How to Use This Calculator?

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