A loose crate handle usually starts with one of three problems: the screw has backed out, the hole has widened, or the handle is taking more load than the original build expected.
Start with the easy check. If the screw still bites, remove it, add a small amount of wood glue to the hole, clamp the handle square, and re-seat the screw by hand so you do not strip the hole further.
If the hole is blown out, plug it with a glued dowel or hardwood sliver, let it set, trim it flush, and drill a pilot hole before reinstalling.
If the handle keeps loosening, the issue may be design rather than the fastener. Wider attachment points, better screws or a thicker side panel can make the next version more useful.
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