High tensile strength 4340 Chromoly is heat-treated tempered and induction hardened to produce these heavy-duty axles that are up to 40% stronger than stock 1040 axles. The latest splining technology to produce splines that are stronger than traditional cut splines. The shafts are then precision CNC machined and magnaflux inspected for cracks before receiving a slick black anodized finish. This front axle shaft conversion kit with ARB locker from Alloy USA fits 84-91 Jeep Cherokee & 87-95 Wrangler Dana 30 front axle.