ASME B18.8.1-2014 pdf – Clevis Pins and Cotter Pins(Inch Series).
2.2.3 Clevis Pin Head Periphery. The periphery of the head shall be within a circular runout equal to 12% of the maximum head diameter or 0.020 in., whichever is greater, with respect to the axis of the shank, as determined over a length under the head equal to the nominal pin diameter.
2.3 Clevis Pin Lengths
All clevis pin sizes are available in a variety of nominal lengths. Table 2 provides a means of determining the cotter pin hole location, M, for all nominal pin lengths, C, for each clevis pin size.
2.3.1 Clevis Pin Measurement. The C and M lengths of the clevis pin shall be measured, parallel to the axis of pin, from the bearing surface of the head.
2.4 Clevis Pin Hole
2.4.1 Clevis Pin Hole Location. The clevis pin hole location is dimension, M.
2.4.2 Clevis Pin Hole Alignment and Angularity. The axis of hole through the shank shall not be offset from the axis of pin by more than 0.010 in. for the 346-in. and 14-in. nominal pin size and 0.020 in. for all larger pin sizes, and shall be square with the axis of pin within 2 deg.
2.4.3 Clevis Pin Hole Chamfer. The hole shall be chamfered or edges otherwise relieved at both ends to remove all burrs and sharp edges.
2.5 Clevis Pin Material and Heat Treatment
Unless otherwise specified by the purchaser, clevis pins shall be made of either low or medium carbon steel.
When case hardened pins are specified, they shall be resistant to a No. 58 file in accordance with SAE 1864. In the event of dispute, case hardness and depth shall be evaluated by micro-hardness according to ASTM E384. The case hardness shall be a minimum of 633 HV (HRC 57) with a depth between 0.010 in. and
0.016 in.
2.6 Clevis Pin Finish
Clevis pins shall normally be furnished with a plain (as processed) finish, not plated or coated. Other finishes, where required, shall he subject to agreement between the manufacturer and the purchaser.
Finishes such as the following are suitable for use on clevis pins:
(a) Electroplating per ASTM B633 or F1941 (cadmium is not a recommended finish)
(b) Hot dipped zinc coatings ASTM A153 or F2329
(c) Passivation of corrosion resistant pins per
ASTM A380
2.7 Clevis Pin Workmanship
Clevis pins shall be free from burrs, loose scale, sharp edges, and all other defects affecting their serviceability.
3.5.4 Cotter Pin Wire Section. Cotter pins are manufactured from approximately half-round wire and it is desirable that the flat side of the wire have a small degree of rounding at the edges rather than sharp corners.
3.6 Cotter Pin Finish
Unless otherwise specified by the purchaser, cotter pins shall be supplied with a plain (as processed) finish, not plated or coated. Other finishes, where required, shall be subject to agreement between the manufacturer and purchaser.
3.7 Cotter Pin Workmanship
Cotter pins shall be free from excessive burrs, cracks, loose scale, sharp edges, and all other defects affecting their serviceability.
3.8 Cotter Pin Designation
Cotter pins shall be designated by the following data, in sequence shown:
(a) product name (noun first)
(b) ASME B18.8.1
(c) nominal size (fraction or decimal equivalent)
(d) pin length (fractions)
(e) point type
f) material and protective finish, if required
EXAMPLES:
(1) Pin, Cotter, ASME B18.8.1, “8 X 1/4, Extended Prong Type, Steel, Zinc-Plated, ASTM F194i, 8A
(2) Pin, Cotter, ASME B18.8.1, 0.250 x 1/2, Hammer Lock Type, Steel, Corrosion Resistant, UNS S30400, Passivated, ASTM A380.