Shield
Gules (Crimson), a lion rampant armed and langued Azure and in chief a key fesswise all Or.
Crest
That for the regiments and separate battalions of the New York Army National Guard: From a wreath Or and Crimson, the full rigged ship Half Moon all Proper.
Motto
SERVITIUM (Service).
Shield
The symbolism is based on the lineage and honors of the previous unit of the same designation. Crimson and yellow are the colors traditionally associated with Ordnance, the predecessor organization. The key symbolizes the Rhineland campaign. The key was a familiar charge in the corporate arms of the towns of Rheinprovinz, the province in which the Rhine River crossing was made, the Siegfried line breached and geographically containing the active area of the campaign. The successes of that campaign were so important that the charged might be termed the key to victory in Europe. The gold lion rampant, from the arms of Bavaria (Bayern), represents the Central Europe campaign which was centered around this province.
Crest
The crest is that of the New York Army National Guard.
The coat of arms was originally approved for the 742d Ordnance Battalion on 22 October 1953. It was redesignated for the 42d Maintenance Battalion on 21 June 1967. The insignia was authorized for the current/different 642d Support Battalion on 31 August 1998 and amended to revise the symbolism on 31 August 1998.