The Science of Feel: Materials, Engineering and Cracking the Code

The “science of feel” may be the ultimate golf oxymoron. How could it be that the most subjective performance attribute in the game – how a club feels when you hit it – is the result of advanced engineering?

One would have to have a soul of stone to sully the art and emotion of feel by bringing math, computer simulation and ultra-modern technology into the equation. After all, didn’t Ben Hogan, the greatest technical tactician/golfer of them all, say it better than anyone?

“A well-hit golf shot,” he told us, “is a feeling that goes up the shaft, right through your hands and into your heart.”

You can’t wax poetically any better than that.

But, friends, we’re on the cusp of 2024. Today, we carry more technology in our pockets than Apollo 11 took to the moon over half a century ago. And while it may not please golf purists, technology can make you feel things that weren’t possible even a decade ago.

And that’s not a bad thing.

The Science of Feel

You may think all you need to make a great-feeling iron is super-soft 1025 carbon steel and a forging machine.

You’d be wrong.

“I can make a 1025 material sound and feel as bad as anything if it’s badly designed,” says Marni Ines, Director of Iron Product Development for Titleist. “The reputation of soft carbon steel should really be attributed to the fact they were designed into muscle-back construction. That’s a structure that will give you very good feel most of the time.”

And, conversely, a crack engineering team could turn the worst, harshest-sounding material imaginable into an incredible-feeling iron.

OEMs, of course, don’t go looking for the worst, harshest-sounding material imaginable for their irons. But it’s important to understand that, when it comes to feel, materials and engineering are equally important to the feel equation.

“The body, the face, the materials, how you design the structure of the body – it all matters,” says Ines.

If you want to get artistic about it, think of feel as a piece of piano music. Each element of design represents a single piano key. Taken together, they represent a full chord in the greater symphony of golf.

“The body is doing one thing, the muscle plate is doing another thing,” explains Ines. “How you attach the muscle plate to the body is another thing. The opening you create for the muscle plate to sit in matters. Where it’s located, how big the opening is, how thick the rim is and how wide the surface area of the attachment is. It’s a big thing.”

Just What Is “Feel?”

In our reader surveys, MyGolfSpy has asked golfers why they bought the irons they’re playing. The No. 1 answer, by a significant margin, has consistently been “pleasant sound and feel.”

“But when we ask those same players to help us define ‘feel’ and what ‘feel’ means to them,” says Titleist Marketing VP Josh Talge, “we get a dog’s breakfast worth of answers – a little bit of everything.”

Whether you define feel as a pleasing click, a confident clack or a tingle-inducing smoosh, you know it when you, ahh, feel it. That one perfect strike makes you go all gooey inside and you tell anyone with ears that you’ve found your reason for living.

“Feel is a combination of three factors,” explains Talge. “One is volume – how loud is it? Second is pitch – how high or low is the frequency? And the third is duration – how long do you hear that noise? When you triangulate those three, we’ve found a really nice sweet spot we know good players are going to like.”

While marketing tells us nothing feels like a Mizuno, OEMs such as COBRA, Srixon and others make some dandy-feeling sticks as well. Titleist has made feel an engineering priority in its T-Series irons since they were introduced nearly six years ago.

“We felt our prior-generation T-200 was a little clicky or maybe clacky,” says Talge. “We sat down with our engineering team to discuss what we wanted to improve upon. And in all caps and double-underlined was feel.”

Diatomaceous Earth

How do OEMs use technology to deliver the science of feel and its kissin’ cousin, the science of sound? Particularly, how can they deliver consistent sound and feel from game-improvement to player’s irons? It’s more complicated than simply making it forged.

Titleist, for one, recognized it had a feel problem with its previous-generation T-200 and T-350 irons.

“By nature, those are hollow-blade construction,” says Talge. “There’s so much space in there that’s going to act like a speaker. You’re going to get vibration and you’re going to get noise. We were getting great numbers. But with an iron, you can’t decouple performance and feel. They are linked.”

As mentioned, Titleist had feel in all caps and double-underlined when it started working on the new T-Series. Talge says the engineering team had a hit list of maybe 32 ideas to improve feel.

“Maybe the second or third one down was ‘diatomaceous earth.’ When they explained it and all the other things they were looking at, it was an a-ha moment for me. Diatomaceous earth maybe wasn’t going to be the thing to solve this. But, gosh, one of those 32 things, or a combination of some of those things, would get us there.”

And for the record, diatomaceous earth, according to Wikipedia, is a soft, naturally occurring siliceous sedimentary rock that can be crumbled into a fine white powder.

The Science of Feel: Pulling Levers

Thankfully, diatomaceous earth didn’t make the cut. But if you’ve tested the new Titleist T-Series, you’ve no doubt found the sound and feel from the T-100 all the way to the game-improvement T-350 to be remarkably consistent.

“That was our feel goal,” says Ines. “We want to give you the feel of a one-piece forging on-center strike with a multipiece construction.”

To do that, engineers pulled several different levers.

“We have tools to simulate sound and characterize and predict sound in a computer,” says Ines. “When you change a material or component in the head, that has to be characterized. Its attachment to the rest of the assembly has to be characterized. We even go so far as to play with different dampening fillers inside the head.”

And one of the biggest levers is what Titleist calls Maximum Impact Core Technology. It’s a silicon disc that’s attached to the face and to a tab (called the Max Impact Bar) that extends from the top rail of the frame into the center of the cavity.

“It provides a level of resilience and dampening,” says Ines. “’Resilience’ is its ability to absorb and return energy while ‘dampening’ is being able to absorb a certain amount of energy from a certain frequency.”

In the new T-200 and T-350, the Max Impact Bar has been relocated closer to the center of the face. Additionally, the Max Impact Core became a little narrower. And Titleist reconfigured the frame geometry, particularly where the shelf attaches to the polymer muscle plate.

“That opening size, shape and amount of surface area on the toe versus the rest of the perimeter makes a difference,” says Ines. “These are the subtleties of engineering this body for sound and feel.”

Little Things Matter

The science of feel extends far beyond the world of golf. BMW, for example, employs a team of sound engineers who work on just one thing: the sound the car door makes when you close it.

 Overkill? You might think so but the sound a car door makes when it shuts subconsciously signals the overall quality of the entire vehicle. It’s no different with golf clubs, as our surveys have pointed out.

“There’s something in sound and feel that subconsciously tells you that, yeah, this is a really good iron,” says Talge.

Granted, feel can be as much of a marketing story as it is an engineering and performance story. After all, Mizuno is the king of feel largely because it tells you “Nothing Feels Like a Mizuno.” Srixon’s ZX irons all have “premium forged feel.” And COBRA says its five-step forging process provides “exceptional feel and feedback with every strike.”

For its part, Titleist combines sound and feel as part of the T-Series’ overall performance package. Getting that sound and feel consistent throughout the line isn’t easy, particularly when half of the lineup is hollow-body construction. You can shove in all the goo, foam or urethane microspheres you want to make them feel better but, any time you do, you limit the face flex and, ultimately, performance. There’s a line you can’t cross.

“Whenever you add anything in there, you’re managing weight,” says Ines. “As soon as you add weight, you have to take it away from somewhere else.  We’re always looking for ways to make our components more weight-efficient so we can add more of these things that we know will improve the feel of the product.”

The Science of Feel: Fitting Matters

While you might not normally equate fitting with feel, it does make a difference. Anything that helps you find the center of the face more consistently is certainly going to make any club feel better at impact, no matter who makes it. And, despite data that might show otherwise, how an iron looks to you will impact how you, pardon the expression, feel about it.

“Eighty percent of our irons are custom fit,” says Talge. “The discerning golfer may not use the same vocabulary that we do, but when they put that iron down they immediately go, ‘Mmmm, this looks good.'”

And custom fitting also leads to combo sets. The challenge, however, is where to transition. Most sets commonly transition between the 7- and 8-iron, often leading to a hinky-looking set. The deeper problem is a hinky loft transition that often requires as much as a two-degree strengthening of the 8-iron through pitching wedge.

That, however, can mess with the sole design and cause those irons to get kind of diggy when it comes to turf interaction.

“Because we have all these irons in the T lineup, we probably have another chassis that can get you there rather than bending something,” says Talge. “Then it’s not going to perform or feel the way you’re expecting it to.”

So while the Science of Feel is as much about engineering as it is about materials, it’s also about fitting. And if you’re investing in a new set of irons, make sure to invest in a good fitting. You’ll feel better about the end result.