WASHINGTON — Congress is moving to renew a 25-year-old ban on firearms that can evade metal detectors and X-ray machines.

The Republican-led House is expected today to approve a 10-year extension on the ban, just days before its expiration.

But with 3-D printers increasingly able to produce plastic weapons, many Democrats want tighter restrictions, such as requiring permanent metal gun components, which would make plastic firearms more detectable.

But Democrats are still expected to back the extension.