The boys were just 20-years-old when they were deployed to Vietnam - Kev thought Tom was a "little fat fella" and Tom thought Kev was a "roughnut"; but what they experienced in the red mud almost 50 years ago has bonded them for life.

Tom and Kev were among the 108 blokes in D Company of the sixth battalion of the Royal Australian Regiment who took on a force of 1,500 to 2,500 from the Viet Cong 275th Regiment during the Battle of Long Tan, in what's been called one of the most savage and decisive engagements in ANZAC history.

Through biblical amounts of rain and choking fog, the men of the beleaguered D Company fought for their lives over three hours on a rubber plantation near Long Tan, in Phuoc Tuy Province, on August 18, 1966.

Kev and Tom's story didn't start there though; rather at the military training camp near Wagga Wagga where they and tens of thousands of other national service men trained.

"I think our mateship started when we were at Kapooka mainly because the things we had to do we had to do together," Tom says.

"There were four or five blokes from Cowra with us and when we went through Kapooka, we were transferred to D Company 6RAR from September right until the time we got on the plane to go to Vietnam."

Their first stop was Vung Tau, where they spent several weeks trying to acclimatise to what Kev describes as "atrocious" conditions.

They then headed to Nui Dat where they broke the ground into the camp.

Tom remembers what hard work it was and how strange everything felt.

"The very first night we got up there we were told to dig in, so we dug in like little rabbits and you wouldn't believe it, an hour or two later after we'd gone down three feet and set all our beds out for the night, the rain came and washed everything out," Tom says.

What they experienced on that first night though was just the beginning.

Labouring through the mud, patrolling through torrential rain and the leeches - Kev said they had no idea what they had gotten themselves into.

On the day of the Battle of Long Tan, Kev said it was "raining like buggery" and the mud was rife.

Under heavy fire, the ammunition belt of Kev's M16 machine gun clogged with mud, and while trying to clean it, he was shot in the shoulder.

"At that time, we were pulling back and these guys were coming in on us. Someone offered Kev a hand and he said no, I can run, and he grabbed his shoulder and pissed off!" Tom says.

It was nearly morning by the time they got out of there and Kev was taken to the camp hospital.

Tom and their mates weren't allowed to see him for security reasons, but said both in the hospital and the camp, no one really talked about the battle, for which the company later received a US Presidential Unit Citation by the then President Lyndon B. Johnson.

Still recovering, Kev returned home before Tom and they didn't see each other for about 10 years after the war.

They only catch up a couple of times a year now, but when they do, Tom says you can feel the camaraderie.

"I grew up very quickly in Vietnam and I met some bloody good mates and I've got them here today," Tom says.

Tom and Kev joined other veterans and members of the community in marking the 48th anniversary of the Battle of Long Tan with a sunset service at Cowra Cenotaph on Monday evening.

Those in attendance laid wreaths and saluted the memorial in memory of the lives lost that day and in all military conflicts since.