The ordinary Machine Gun Corps' cap badge was the first official badge of the Heavy Branch. It was not universally popular and many of its members retained the badges of their original Regiment or Corps. By 1917 the new Branch was seeking its own distinctive badge, but as this was a matter for which Royal approval was required and would take time, the War Office agreed that a worsted arm badge would be introduced until the cap badge was approved.
The Army Order authorising the badge (79 of 6 February 1917) decreed that it should be worn on the right arm three inches below the point of the shoulder. It also states that 'It is to be worn by all ranks'. This would appear to dispel the popular myth, perpetuated by the Regimental History, that it was only awarded to trained tank crewmen. Certainly for many years all members of the RTC/RTR have worn it on service and battle dress.
A silver embroidered version was worn on the other ranks pre-war blue patrols and the Band had a gold embroidered one for their full dress. In 1996 the RTR Council directed that the gold embroidered badge was to be worn on both Officers' and Warrants Officers' and Sergeants' Mess Dress. They do wear a silver embroidered version on No 1 Dress and No 3 Dress (tropical white equivalent of No 1 Dress) although a brass badge has been worn instead on No 3 Dress (Fourth in Malaya 1964). This brass badge was also worn by officers and men on khaki drill and olive green tropical dress.
The arm badge is not worn on combat dress, it is however worn on parade black overalls.