Article by Sandvik
In this project, Sandvik gathered experts from across the company to
demonstrate how they could use sustainable, cutting-edge techniques to
make something that is both highly precise and amazingly durable. Henrik
Loikkanen, the Machining Process Developer at Sandvik Coromant, has
played guitar since his youth when he idolized Malmsteen. To understand
what happens when Malmsteen destroys an instrument, Loikkanen turned to
“We had to design a guitar that is unsmashable in all the different ways
you can smash a guitar,” Loikkanen said. “The engineering challenge was
that critical joint between the neck and the body that usually cracks
on a guitar.”
Sandvik engineers eliminated the joint between the neck and body.
Instead, the guitar’s neck and fretboard were milled from solid bars of
recycled stainless steel, a guitar construction that had never been
tried before. Both the neck and fretboard extended into a rectangular
“hub” that would reach deep into the guitar’s body.
Long, slender components like the fretboard and neck are particularly
vulnerable to distortion. Advanced software allowed Sandvik Coromant to
simulate milling digitally before the first cut was made, enabling the
correct choice of tools, saving manufacturing time and ensuring
“Precision was critical,” said Henrik Loikkanen, machining process
developer at Sandvik Coromant. “Our software is built on years of
experience, giving tool and the cutting data recommendations that helped
us mill the fretboard down to a challenging thickness of 1 millimetre
A 3D printed titanium body in layers
Meanwhile, another challenge was being tackled – how to manufacture the guitar body, an extremely complex design due to the need for high strength at low weight.
Sandvik, relying on its world-leading expertise in metal powder and additive manufacturing, decided to 3D print the body. Lasers traced the design into beds of fine titanium powder, fusing layers of material one on top of the other. The layers, each thinner than a human hair, built up into the body of the guitar.
“Additive manufacturing lets us create lighter, stronger and more flexible components with internal structures that would be impossible to mill traditionally,” said Amelie Norrby, an additive manufacturing engineer who participated in the guitar project. “And it’s more sustainable because you only use the material you need for the component, minimizing waste.”
The materials world
Tomas Forsman, a research and development specialist at Sandvik, realized that the guitar needed a special structure that was strong, stiff and light. He proposed an Isotropic Lightweight Structure (ILS), the strongest structure for a given weight ever invented.
“It looks much like any framework structure,” Forsman said, “but it’s actually stiffer and lighter than anything we’ve seen before.”
Forsman also knew exactly the material from which the ILS should be constructed: hyper-duplex steel, a grade only Sandvik produces. He wanted to sandwich the hyper-duplex ILS between the guitar’s neck and fretboard.
“To break it is impossible. But you can break other things with it” –Yngwie Malmsteen
But the fretboard could not afford any torsion, a problem with welding long, thin components together. Analysis and testing fine-tuned the welding process until the ILS could successfully be integrated.
Forsman thinks the guitar project and the collaboration it required illustrates how Sandvik’s deep expertise and experience can solve unique challenges, even faced with short timeframes.
“Collaborating like this is a key for the future,” said Forsman. “Our customers’ challenges continue to grow more and more complex. We need to bring our expertise to work hand-in-hand with our partners and customers and keep inventing new ways of meeting those challenges.”
When the guitar was finished, Sandvik gave it to Malmsteen to play. At a club in Florida, Malmsteen ripped through several songs, then started swinging the guitar at amps, at stage structures, at the floor, doing his very best to smash it.
“This guitar is a beast!” Malmsteen said after abandoning efforts to destroy it. “Sandvik is obviously on top of their game. They put the work in, they do their hours. I can relate to that. The result is amazing. I gave everything I had, but it was impossible to smash.”
- The guitar took three months to make from designing to finished instrument
- The guitar body was produced in titanium using powder bed fusion, an additive manufacturing technique where lasers melt metal powder into microscopically thin layers.
- The volume knobs and tailpiece which anchors the strings were also created with 3D printing.
- The guitar neck and hub were milled from one piece of stainless steel.
- The back of the guitar’s neck is hollow and is only 1mm thick in places.
- The hyper duplex lattice-like Isotropic Lightweight Structure inside the guitar neck is the strongest structure in the world for its weight.
- The scalloped fretboard, a trademark of Malmsteen’s guitars, is inspired by the ancient lute.