Holding Speeds

The maximum indicated airspeeds for holding in the United States: 200 KIAS from the minimum holding altitude through 6,000 feet MSL, 230 KIAS from 6,001 to 14,000 feet, and 265 KIAS above 14,000 feet. A hold between 6,001 and 14,000 feet may be limited to 210 KIAS, shown by an icon, and any hold may carry a lower limit printed inside the racetrack, such as (175); a pilot unable to comply should tell ATC. Holds at USAF airfields allow 310 KIAS and at Navy fields 230 KIAS unless charted otherwise. Within three minutes of a clearance limit with no further clearance, slow down so as to cross the fix at or below the holding speed: crossing it faster can take the aircraft outside the protected airspace.

Source: summarized from AIM 5-3-8.

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