Rugged Strength. Heavy-duty frames fusion welded with 1.5” to 3” 11-gauge tube steel. (RZ models and up). Fabricated 7-gauge steel decks. (Defender and up). Upgraded spindles with increased durability, improved element resistance, and incorporated blade fastener lock to prevent the blade mounting fastener from gaining torque during a hard impact. Thicker baffles of 7-gauge steel increase deck durability.