Imao’s pulleys are available from a wide variety of materials and sizes.

RABS: Flanged Idle Pulleys
・ Lower flange height for conflict-free conveyance
・ Stable rotation with ball bearing
・ Steel body for high wear resistance
・ Applicable to 10 - 40mm belts
・ For 8mm, 10mm and 12mm diameter spindle
Use with PID Idler Pins.

Materials:
Pulley body: S45C Steel, Electroless nickel plated finish
Bearing and Retaining Ring: Steel

Datasheet: https://www.imao.co.jp/files/on-cat/pdf/en/rabs-e.pdf

Parameter Name	Parameter Value
Type	roller
Applications	belt tension
Other characteristics	metal bearing
Pitch diameter	Min.: 30 mm (1.18 in)Max.: 60 mm (2.36 in)
Outside Diameter	Min.: 33 mm (1.3 in)Max.: 66 mm (2.6 in)
Hub diameter	Min.: 8 mm (0.31 in)Max.: 12 mm (0.47 in)
Width (mm)	11 - 41