Know When to Fold ‘em: Why It’s So Hard for Multi-Tools To Stay Tight


Know When to Fold ‘em: Why It’s So Hard for Multi-Tools To Stay Tight

If you use folding multi-tools, you’ve probably used one that’s gotten loose over time. Travis set out to find a permanent solution. He failed.

Folding multi-tools are a necessary evil. They’re compact, comprehensive, and convenient. I rely on them pretty regularly. But they’re far from optimal. The T-handles or mini ratchets or even good ol’ “L” wrenches in your home tool kit will offer better torque, ergonomics, and maneuverability than even the best folding multi-tools. Also, those standalone tools will never develop the dreaded “flop” that will plague nearly every folding tool at some moment in its life. You probably know that moment. When the hinges loosen up, and the T25 you need goes limp, along with all the bits next to it. This has always seemed like one of those “we can put a man on the moon…” kinds of problems, but while I was trying to write an explainer on how to fix it, I learned it’s actually a marvel that folding tools stay together as long as they do.

Bolts are designed to be tight. Even if they’re holding down a freely moving part, there’s of course some mechanism to facilitate that movement. Maybe it’s the locknuts on a cup-and-cone hub design, or the rigid sleeve between bearings in a suspension frame’s main pivot. But folding multi-tools are unique. Unlike wheels and pivots, they’re not supposed to move freely. They need enough friction for that T25 to remain at a nice 90° angle as you align your brake lever, but not so much friction that they can’t be easily folded flat when you’re done.

Also unlike wheels and pivots, there’s very limited space inside a multi-tool. Most (like the tool pictured above) pivot around a small threaded pin, which accepts an even smaller threaded bolt. They couldn’t reliably have a locknut or sleeve or other complex way to fine-tune optimal friction. And realistically, they could not be manufactured to such tight tolerances that, when bolted together at 8 Nm, they’d always end up with the perfect amount of friction. Even if they could, that perfection would likely fade as the metal deforms with use.

So, most tool brands coat the bolts or nuts with thread-locking material to keep the whole assembly assembled even though nothing is actually “tight.” But all thread-locking materials change over time. Twisting a multi-tool stretches and compresses the thread-locker that holds it together, eventually reducing its effectiveness. So, like, what the hell?

Every folding multi-tool I’ve ever used has eventually loosened up, regardless of the manufacturer. So, this is a widespread issue, but I got some pretty straight talk from Lezyne. That’s who we’ll be hearing from, peppered with background information from the FAQ section on the Loctite website. Loctite would seem like the obvious place to start, but the substance used when assembling your multi-tool may not technically be Loctite. At least in Lezyne’s case, it’s something fundamentally different.

“Nylok increases friction, while Loctite is made to glue a thread tight,” Lezyne explained. Nylok is a brand-name coating. It’s not to be confused with the generic term, “nyloc.” Nyloc nuts have a little plastic ring captured at their exit to keep bolts from vibrating loose. Nylok (the brand) does make bolts with a similar mechanism, where a small chunk of plastic is embedded somewhere in the bolt’s threads. However it’s done, the effects of these “mechanical” means of holding tension are essentially the same, but they don’t work anything like Loctite. “Nylok is pre-applied and cures in an oxygenated environment, while Loctite cures when there is no oxygen (a tight thread).”

This is where my plan to really crack this case kinda fell apart. I assumed that science had provided us with Loctite for this very purpose. I just needed a multi-tool brand to admit they can’t (or don’t) apply it properly during manufacturing, and we consumers just need to do it ourselves. But there’s just no way for Loctite to permanently solve the problem. It certainly never has for me. Sure, it fixes the issue for a while, but it never lasts. And Lezyne’s answers helped explain why that is.

“In order to keep your tools loose enough to turn, you don’t always create enough pressure/tightness for the Loctite to cure correctly. So, while Nylok is less permanent, it is more adapted to this use case.” Because Loctite creates a chemical bond, and doesn’t simply add physical friction, once you break Loctite’s bond, it won’t work the same until a fresh, uncured coat is applied. Nylok coating isn’t permanent either, and will need occasional adjustment, but it will last for “multiple cycles,” according to Lezyne. Unfortunately, Nylok is not the sort of thing you can pick up in your local hardware store’s checkout aisle along with a key silencer and a Snickers. Nylok is applied at a massive industrial scale, and you can’t easily buy just the two tiny unique bolts in your multi tool pre-treated with Nylok.

So, if you must resort to using Loctite, here are some tips:

  • Use blue Loctite. Red is not significantly better at permanently fixing the root causes of multi-tool looseness, and it’ll be very difficult to adjust when you need to.
  • Thoroughly clean all surfaces before applying Loctite. It only cures when in contact with metal, and residue of old Loctite will inhibit proper curing.
  • Loctite is particularly stubborn when used on stainless steel threads, common on multi tools. In addition to a thorough cleaning, you may need to apply a primer.
  • All tools are different, but Lezyne suggests a torque of 2-3 Nm is ideal for their tools.
  • Be ready to go through process again if the problem comes back.

Like I said, this is not quite what I hoped would come of this story, but at least now I’m a little less confused about exactly why I’ve always needed tools to fix my tools. And maybe someone out there has had a better experience trying a different remedy. If you’ve ever had success with Loctite, or maybe with something cool we don’t even know about, let us know in the comments.