About HeliCoils – Pros and Cons

HeliCoil at Ace HardwareThe Ace helpful hardware man will sell you HeliCoil kits to fix most damaged threads that homeowner’s may encounter. Nothing surprising about that. After all, Helicoils are the most popular, well known brand for fixing damaged threads. Below, you’ll find 10 things that your friendly neighborhood Ace Hardware man won’t tell you, especially when it comes to automotive applications…. because he simply doesn’t know.

Pros and Cons

  1. Heating and cooling are HeliCoil’s enemy. In automotive applications where heating and cooling occurs, which causes expansion and contraction causes HeliCoils to loosen and fail!
  2. HeliCoils are porous and therefore cannot hold combustion gases. Threads that need to be repaired for spark plugs need a solid insert, not one that is simply a coil of wire that could never hold up to combustion gases.
  3. HeliCoils have no plan B. Once a HeliCoil fails, you can only drill the hole out larger and jump up to the next size. There’s no Over Size kit available that accepts the same size as the original bolt. Time Sert makes a Big Sert to repair holes that a Helicoil has failed in. Their kit is called Big Sert.
  4. Helicoils can back out when removing the bolt next time. Since Helicoils are only held in with “spring like” action, they are not a secure part of the repaired item when installed. Therefore they can easily back out.
  5. HeliCoil tangs/tabs are meant to break off after the installation. Problem is the tang can fall into the hole causing damage in some cases, depending on what’s being worked on.
  6. Helicoil spring inserts don’t always come in the desired length. Stacking them will result in damage to the bolt or Helicoils when the bolt has been installed. This is because the threads never line up properly when double-inserted.
  7. Helicoil wire inserts cannot have Loctite applied only to the outside threads. In many cases, only the outside of the threads should have thread sealer applied. Like when spark plug threads are repaired.
  8. HeliCoils cannot handle as much torque as a solid bushing type insert can, like Time Sert. Many guys discover this when repairing head bolt threads and the HeliCoil fails on the last pass with the torque wrench.
  9. HeliCoils always sit down in the hole and can sometimes go too far and drop in! Time Sert inserts have a flange that prevents this.
  10. Helicoil problems sometimes are caused by installing them crooked. There’s no guides available like with Tim e Sert kits. Helicoil has very few specialized kits compared to Time Sert.

The Pros of the HeliCoil brand,¬†which most auto techs have used, is that in many cases they work. In most cases they can be found locally. No drilling is required. Both HeliCoil and Time Sert are made in the USA. With that said, the cons far out weigh the pros. And if there’s a better solution for a problem, should it be used? See all the Time Sert kits for specialized applications at Wise Auto Tools.com and DenLorsTools.com