I thought a fluted tube was a tube with grooves running down it.
I'd call it a dimple/crimp. or a cutout if it's been cut out and plated.
@O'Shane started
London Fixed Gear and Single-Speed is a community of predominantly fixed gear and single-speed cyclists in and around London, UK.
This site is supported almost exclusively by donations. Please consider donating a small amount regularly.
I thought a fluted tube was a tube with grooves running down it.
I'd call it a dimple/crimp. or a cutout if it's been cut out and plated.