TY - RPRT TI - Report no.32 : Ultrasonic instrumentation to measure hoop steel in cast-steel railroad wheel rims AU - Schramm, Raymond E PY - 1998 PB - National Bureau of Standards CY - Gaithersburg, MD SN - NBS TN 1399 DO - 10.6028/NIST.TN.1399 ER -