Grooved cylindrical shafts with cross holes, bar turned within the small-parts range of ø5mm up to ø30mm, here as three identical pieces. Each has bands of fine circumferential grooves at both ends, a narrower neck in the middle, and cross-drilled holes in two sizes through the body. The machined surface is bright silver. Materials offered for this group are brass, alloy steel, aluminium and stainless steel, and production volumes range from thousands to hundreds of thousands, so batches scale up while precision is kept.