James Hetfield launches his first-ever signature guitar strings with Ernie Ball

Ernie Ball has partnered with Metallica's James Hetfield for his first-ever signature set of electric guitar strings, Papa Het's Hardwired Master Cores.

Developed over the past decade, the strings boast a “never-before-offered” 11-50 gauge combination – 11, 14, 18p, 28, 38, 50 – and come housed in a bright green metal tin with custom artwork designed by Hetfield himself.

Named ‘Master Core’ for their heavier core-to-wrap ratio, the bottom three strings in the set consist of an ultra-high strength tin-plated steel hex core wrapped with Ernie Ball-designed Paradigm plasma-enhanced nickel-plated steel. This design, EB says, means a thicker sound and added pitch stability.

“It's only taken 40 years for me to have my own strings,” Hetfield says in a new clip. “Come on!”

“With all the companies we're with, we're super-proud to be with Ernie Ball,” he adds. “For them to take on the challenge of, ‘Hey, I've got an idea, can you do this...’ they have stepped up to the challenge. I'm super-proud!”

Papa Het's Hardwired Master Core Signature Strings are available now from the Metallica.com Store at $34.99 for three sets, and will be available through domestic and international Ernie Ball retailers from May 10.

In other Metallica news, in a new interview with Metal Hammer, former bassist Jason Newsted revealed that during the making of the Black Album, he “struggled” with Nothing Else Matters, and thought Enter Sandman was “kinda corny” when he first heard it.

“[Nothing Else Matters] made the hairs on the back of my neck stand up, it was undeniable,” he recalls, “but I was kinda scared of it, to be honest, because I still wanted ‘crunch’!”

But he says the track was instrumental in the band's subsequent success, as it “took down the biggest walls to allow our hardest songs ever to penetrate the world”.