Quote from HSBC website:
Wire Transfer requests submitted before 3:00 PM Eastern Time (ET) on a business day will be processed the same day. Wire Transfer requests to domestic banks can be completed online at any time, however, those completed after 3:00 PM ET on business days will be automatically re-dated to the next business day. Wire Transfer requests to banks in other countries can only be completed between 7:00 AM and 3:00 PM ET on business days. International Wire Transfers can be cancelled for up to 30 minutes after the request has been completed with no penalty.
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Says up to 30 minutes with no penalty, implying you can cancel them even later for a fee.
Sure, they actually do not send the funds in the first 30 minutes for International Wire Transfers, so free cancelation is possible. Also the receiver will see the funds only after few days if International Wire Transfers is used