Replacement brass tubes are the difference between salvaging a blow-out and starting over. If you've ever drilled a blank slightly off-center, blown out the wall of a soft burl, or cracked a tube during assembly, you know the value of having spare tubes on the shelf. We stock brass tubes sized to match every pen kit family in our catalog — slimline (7mm), Sierra, Jr II, bolt action, cigar, and many more. Buy a few extras with your next kit order; they're inexpensive insurance against the inevitable.