2-7/16" One-Piece Split Clamp-Type Shaft Collar, Aluminum" Smooth bore protects shafts from damage Superior holding power over set screw type collars Offered in High Strength, Low Profile and Heavy Duty styles Stocked in a variety of materials 1 Piece Clamp Type Shaft Collars are for use on standard round shafts, hard or soft, as well as on thin wall tube or over a split hub. Precision machined, non marring, easy to adjust, with high clamping power, they are stocked in the following materials: Steel