[CharlesM]

I can't find annything that mentions face-hardened armour on halftracks.

As for PzKfw IVs, it seems to depend on sources.

My previous post about German tanks is from Lorrin Rexford Bird and Robert D. Livingstone, World War Two Ballistics: Armor and Gunnery, 2nd edition, Overmatch Press, Albany NT and Woodbridge Conn 2001. No ISBN is given.

No two sources seem to agree on the PzKfW IV,and Tom Jentz's Osprey New Vanguard # 39 on the PzKfw IV Ausf. G, H and J is rather vague when he describes the Ausf. G as having face-hardened 50mm frontal armour and 30mm side plates - implying that the turret sides were also FH plates. The earlier Osprey Vanguard # 18 by the late Bryan Perrett mentions FH armour only in the context of British examination of a captured Ausf. E. The applique armour over the hull MG mounting was FH, as were "the port armour covers". The 20 + 20 mm hull sides were not FH.

This lack of consistency is not surprising and not unique to German AFV construction - much would depend on the availability of FH plates during construction. Bear in mind that FH was an expensive exercise as a large number of plates were cracked and had to be discarded, and ultimately the game was not worth the candle, especially as plates became progressively thicker in the gun / armour race.