Direct Answer
A cope is a rectangular notch cut from the flange of a beam to allow it to pass over or connect to a supporting beam or column flange without interference. On shop drawings, a cope is dimensioned by its depth (flange + fillet) and its setback (horizontal distance from the member end), and it must be clearly called out because it is a fabricated cut — not a standard feature of the rolled section.
Full Explanation
Copes are typically required where a secondary beam frames into a primary beam at the same flange elevation. Without a cope, the top flange of the secondary beam would clash with the top flange of the primary. The cope removes a portion of the secondary beam's flange so it can nest into the connection. AISC Design Guide 2 provides limits on cope depth and length to prevent web crippling and block shear failure. Cope dimensions must be confirmed against actual section geometry — the cope depth for a W12 is different from a W16.
What This Means for Your Shop
Incorrect cope dimensions are a leading cause of field fit-up failures. An over-deep cope weakens the web; an insufficient cope means the beam won't fit. Verify cope dimensions against the actual section's fillet dimensions (k-distance), not nominal values from a table.
Common Mistakes
Using a standard cope depth without checking the k-distance for the specific section size and weight. The k-distance varies by section — a W14×53 has a different k than a W14×82.
Recommended Process
The detailer should calculate cope dimensions for every coped condition in the model, referencing AISC section tables for k-distances. Shop floor personnel should verify each cope dimension against the actual member being cut before burning.