Clevis Pin Sizes are given in the following chart according to ASME B18.8.1 standard.

Some important notes from the ASME B18.8.1 standard:

- Material and Heat Treatment: Clevis pins shall be made from low carbon steel unless otherwise specified. Case hardened pins shall have a case depth of 0.010 to 0.016 in.

- The axis of hole through shank shall not be offset from the axis of pin by more than 0.010 in. for the 3/16 and 1/4 in. nominal pin size and 0.020 in. for all larger pin sizes.

- The tabulated length apply to pin intended for use with standard clevises, without spacers.

- Designation: Name, Nominal Size, Length, Material and Finish. Ex: Pin, Clevis, 1/4 x 0.77, Steel, Zinc Plated


Nominal Pin Size


Clevis Pins Dimensions
Parameter Symbol Value Unit
Nominal Size - --- inch
Basic Pin Diameter - ---
Maximum Shank Diameter Amax ---
Minimum Shank Diameter Amin ---
Maximum Head Diameter Bmax ---
Minimum Head Diameter Bmin ---
Maximum Head Height Cmax ---
Minimum Head Height Cmin ---
Head Chamfer (+/- 0.01) D ---
Maximum Hole Diameter Emax ---
Minimum Hole Diameter Emin ---
Maximum Point Diameter Fmax ---
Minimum Point Diameter Fmin ---
Basic Pin Length 1 G ---
Head to Center of Hole (Max) Hmax ---
Head to Center of Hole (Min) Hmin ---
End to Center Ref (Basic) 2 J ---
Head to Edge of Hole Ref (Min) 3 Mmin ---
Recommended Cotter Pin
 Nominal Size
- ---

Note 1: Pin Length tabulated is intended for use with standard clevis, without spacers. When other lengths are required, it is recommended that they be limited wherever possible to nominal lengths in 0.06-inch increments.

Note 2: Basic J dimension is specified for calculating hole location from underside of head on pins of lengths for non standard length clevis pins.

Note 3: For M, reference dimension provided for convenience in design layout and is not subject to inspection.


Cotter Pin: A pin that is fitted through a hole and then bent backwards to lock the pin in place. Cotter pins are used to lock clevis pins.

  • ASME B18.8.1-1994, Clevis Pins and Cotter Pins (Inch Series)
  • Oberg.E , Jones.D.J., Holbrook L.H, Ryffel H.H., (2012) . Machinery's Handbook . 29th edition.  Industrial Press Inc. , pp 1747