Comparison : Item # B61-03.170-T6AS, 6061-T6 AS I-Beam 3" x 2.330" x 0.170"
Item # B61-03.150-T6AA, 6061-T6 AA I-Beam 3" x 2.500" x 0.150"
Item # B61-03.349-T6AS, 6061-T6 AS I-Beam 3" x 2.509" x 0.349"
Item # B61-04.190-T6AS, 6061-T6 AS I-Beam 4" x 2.660" x 0.190"
Item # B61-04.326-T6AS, 6061-T6 AS I-Beam 4" x 2.796" x 0.326"