Cast iron V-groove wheels are made specifically for use on inverted angle iron tracks; they can also be used on flat surfaces. Strong durable wheels at an economical price. Each wheel has a precisely machined 90° V-groove with relief groove which enables load equalization. Tensile strength of 30,000 PSI. Temperature range: -45° F to 600° F. Includes 3/4" Roller bearing with 1/2" ID Spanner Bushing Bore: