The ornamental design for a 3 wayedgeclamp, as shown and described.
FIG. 1 is a perspective view of the 3 way edge clamp.
FIG. 2 is a front view thereof.
FIG. 3 is a top view thereof.
FIG. 4 is a bottom view thereof; and,
FIG. 5 is a side view thereof.
The broken line showing of parts of the drawings is included for the purpose of illustrating use and environment and forms no part of the claimed design.