2pcs Step Spur Gear 5mm Inner Aperture 16T 1 Module Aluminum Motor Gear HSS Lathe Tool Bits you can wrap tape on

you can wrap tape on the metal tube (not included)

put tube in it

and wear protective glasses when using this corundum grinding bit

Inner Diameter: 26mm/1 inch

which is rust-free

2pcs Step Spur Gear 5mm Inner Aperture 16T 1 Module Aluminum Motor Gear HSS Lathe Tool Bits you can wrap tape on1. The pinion motor gear is made of Aluminum, more stable, anti wear, strong and durable, and durable in use. 2. Specifications: Material: Aluminum, Teeth: 16T, Gear Step Diameter: 10mm 0. 39inch, Gear Step Height: 6mm 0. 24inch, Outer Diameter: 18mm 0. 71inch, Aperture: 5mm 0. 2inch, Effective Tooth Length: 6mm 0. 24inch, Total Thickness: 12mm 0. 47inch, Module: 1 Mod, Pressure Angle: 20 3. The pinion gear aperture is 5mm and the module is 1, please