Time-Sert VS Heli-Coil Thread Repair Kits – Which one is better?

8:14 am Head Gasket Repl., TIME-SERT Kits


© DenLorsTools.com Summary:  Article by a master auto tech on the differences in two very popular thread inserts used for restoring damaged threads. Some commonly asked questions are answered like – How are they held in? And which one stays in better? Which is better, Time Sert or HeliCoil? After reading the article and seeing the video be sure to check out our Time-Sert Kits.

Denlor’s sells several different brands of repair kits to fix damaged threads for a variety of applications. Since many engine blocks today are made of aluminum, a common thread failure is the for the head bolts.

HeliCoil for Head Bolts

I remember years ago, guys using small Helicoils which were the right diameter and thread pitch but shorter in length. They would double them up. Then they would run the headbolts in even though they had to be cross threading them when they reached the second helicoil insert. This was a make-shift way of replacing the threads that would work most of the time, if they didn’t have to remove the bolt again. Now, Heli-Coil makes a kit that has the 11×1.5mm common thread size which is 30mm long – no need to double up the the shorter coils. The kit number is 1130. Heli Coils are are held in by the spring action of the coil outward on the tapped hole… that’s it. Once the bolt is installed it helps to hold the coil of wire in place as well. One issue with this method of holding the coil in place is the possibility of the coil traveling further down the hole with the bolt – unless it bottoms out; or having the coil come out with the bolt when it is removed.

Time-Sert Inserts for Head Bolts

Time Sert inserts for head bolt applications are much thicker than the Helicoil brand. They are more like a solid metal bushing which is threaded on the inside and out. The Time Sert brand insert is installed with a special driver. You see, the bottom part of the TS brand insert, by design is not 100% completed until fully installed with the driver. The driver runs the insert down into the hole, it also finishes making the threads while pushing outward on the bottom portion of the insert. That’s what holds it in. When an insert is held in from the bottom it naturally stays in better. And with Time-Sert’s oversize inserts which are called “Big Serts” they take it a step further. Time Sert uses a cam lock method which further assures the insert is held in for good.

Can I use my Helicoil tap to install a Time-Sert Insert?

No, they are completely different. Installing a Time Sert insert without the proper tooling will most likely result in not being able to install the insert to begin with. If for some reason it was possible to install it without the driver, the insert threads would not be completed and the insert would not be locked in place as it was designed. Then the bolt threads might be damaged when installed.

Can I use permanent Loctite on Helicoil and Time Sert inserts?

Since the Heli-Coil is not solid, it actually is just a thin coil of wire, it would allow Loctite to contact the bolt threads. So, it’s not a good idea to use permanent Loctite on HeliCoil brand inserts.  Since Time-Sert inserts are solid, permanent Loctite can be used with no problem. Of course it’s best to be careful to NOT allow the permanent Loctite to come in contact with the bolt threads themselves. See the video below showing the HeliCoil brand and the Time-Sert brand 11×1.5 mm inserts. You be the judge.


Click to see the product listing for the Helicoil 1130 Kit for sale now.

14 Responses
  1. frank :

    Date: January 2, 2013 @ 6:07 pm

    well i do agree but i have just one headbolt that wont go in and its not worth spending almost $400 for just one

  2. dennisb - Auto Tool Sales :

    Date: January 2, 2013 @ 7:34 pm

    Frank, we have a Buy-Back plan. Also, you may want to consider doing all of them because it would be a shame to have a problem with the other threads after so much work. Steel has much more tinsel strength than aluminum. Good Luck.

  3. Dave :

    Date: February 1, 2013 @ 8:47 pm

    $450 for the kit? Is it made out of solid gold? You must be out of your mind. And, your company seems to be the only ones selling the kits as you are entirely dominating the Google search for them. Way to go.

  4. dennisb - Auto Tool Sales :

    Date: February 2, 2013 @ 7:57 am

    Dave, thanks for the comment. This type of tooling is very expensive to engineer and to manufacture. The company that makes Time Sert kits started in the early 1970’s and has distributors all over the world. Time Sert products are made in the USA maintaining very high quality standards. Time-Sert is recommended by leading car manufacturers as further testament to their quality. DenLors Tools started selling Time-Sert products around 2008, simply because many of our customer’s needed the products. In fact prior to us handling this brand, we would refer customers to Time Fastener when we did not have a kit for our customer’s application. While there are many different size kits for numerous applications, both very specific and general; Time-Sert kit prices are the same for a particular kit number, no matter where you purchase it due to MAP (Minimum Advertised Pricing) mandated by the Time Fastener Company.

    At DenLors, we add value by providing free Next Day shipping on certain kits that are priced around $400. We also have a buy-back plan on some of these more popular kits. The Buy-Back plan is for our customers that only need to use a kit only once. As far as ranking well in Google search, that has to do with having unique content related to the subject matter. I suppose you could say, answering questions like yours, as well as application and “how to” questions have helped our website rank well for Time-Sert Kits and various other specialty tools. Many websites only sell products and don’t take time or they don’t have enough knowledge to answer questions and post the information for everyone to see. I’m an ASE master tech with over 25 years hands on experience. Part of my job is spending many hours answering questions helping our customers get the correct product quickly so they can get their repair done fast. Dave, thanks again for taking the time to comment and for the opportunity to answer your concerns.

    *Update on the Buy-Back Program – Unfortunately, the manufacturer now prohibits us from having the buy-back program and selling used Time Sert Kits. We still offer free next day shipping on kits $400 or more which is a great added benefit to our customers.

  5. Hany :

    Date: February 4, 2013 @ 5:17 pm

    I have a question, I did Helicoil on my BMW an unfortunately one came out with the bolt after half way of torquing the cylinder head when I decided to replace the bolts, the question is can I use the Time Sert on the same tapped hole after extracting all Helicoils and of course after boring the block for the Time Sert seats?

  6. dennisb - Auto Tool Sales :

    Date: February 4, 2013 @ 5:54 pm

    Hany, the Heli-Coils as you’ve found out are not very forgiving. At best they are OK for running the head bolts down one time. Once you start running them down it’s like reaching a point of no return. The good news is that the Time Sert can be used. Since the holes have been Heli-Coiled, the Time Sert oversized kit must be used which is called “Big Sert”. On the BMW M10x1.5mm that would be the 1090BS that comes with line-up brackets or the 1087BS which comes without the fixture. The fixture helps to insure drilling is done at the proper angle (straight up and down). Click on the numbers above to see the product listings. Since Heli-Coils are not as thick and are not held in as well as the Time Sert inserts I install all 14 Big Sert bushings just to be safe. Good Luck.

  7. Chris :

    Date: July 24, 2013 @ 2:14 am

    You stated that two heli-coils would cause cross threading when the bolt reached the second coil. But the helicoils ride in a thread that must have been made with a single tap. how could the second heli-coil possibly be shifted to the point of cross threading when it is riding in the same tapped threads?

  8. dennisb - Auto Tool Sales :

    Date: July 24, 2013 @ 7:58 am

    Chris, I see what you are saying and it’s possible that the bolt will thread perfectly into the second coil. The Helicoils are flexible though and have tangs that have to be broken off after the installation which can possibly affect their position and shape. It has been my experience when I doubled them up in a hole that once the bolt reached the second coil, I could feel the bolt turning much harder at that point indicating a cross thread condition. I remember another instance where a tech had to remove the head bolts after experiencing the same sensation of cross threading, only to find the coils damaged beyond being able to use them. They partially came out wirey, which leaves them useless on a second try. Helicoil does make an 1130 lit that has long enough coils to use on head bolts. The problem that I’ve been told by customer’s is that the tooling is not long enough to work on some depths. If the threads were at the top the tooling would be a sufficient length. I’ve added the image of instructions from the inside cover of the 1130 kit’s lid. Look at the bottom of the article above. Notice the part about striking sharply with a hammer to break off the tang.

  9. yaski :

    Date: September 17, 2013 @ 7:04 pm

    Hello, i’ve tapped a stripped hole with Helicoil 1/2x20tap kit. will this tapped hole accept a 1/2×20 Timesert insert? i noticed the Timesert kit has the same 33/64″ drill bit as helicoil. Maybe I lucked out and they share the same tap? Someone mentioned that they share the same STI “standard threaded insert” tap. can you confirm before for me please? Thank you.

  10. dennisb - Auto Tool Sales :

    Date: September 18, 2013 @ 10:28 am

    Yes the drill bit is the same size, a 33/64″. But Time Sert utilizes a class 3 tap size and Helicoil uses a slightly larger tap size. That’s why Time-Sert recommends to using their Time-Sert brand taps when doing a repair. There have been cases when someone has already tapped a hole for a Helicoil and want to use a TIME-SERT and it has worked out fine. Also the Time-Sert kit has a driver which expands the bottom of the insert making it self locking. I would also recommend using loctite as extra insurance. That’s something that you cannot do with a Helicoil (because it is not solid like a Time-Sert insert). *Note we do not sell just components of kits unless we have a record of you purchasing the entire kit from us previously. This helps prevent customers from doing an improper installation.

    If a Helicoil has already been used and it has failed, a BIG-SERT kit is needed to repair the damaged hole. The Big Sert has a larger outside diameter but still accepts the same size bolt since the inside diameter is the same size. Good Luck.

  11. Terry :

    Date: August 1, 2016 @ 12:09 pm

    I have ford flywheel with stripped bolts. Most likely the threads in the crankshaft. The bolt size is M10 X 1.0 Will the time-serts work for this?

  12. dennisb - Auto Tool Sales :

    Date: August 1, 2016 @ 12:54 pm

    Hello Terry, yes. The Time Sert 1010 is M10 x1.0. The 5 inserts included in the kit are 15mm long. You can order more also, or different lengths if needed.

  13. greg :

    Date: October 26, 2016 @ 8:02 pm

    Need to repair a stripped starter bolt hole on an 04 Chevy Duramax 6.6 diesel engine. The bolt is a M12x1.75. Do I use the Time Sert 1217 kit or do I need the 1217BS kit? Thank you.

  14. dennisb - Auto Tool Sales :

    Date: October 27, 2016 @ 12:13 pm

    Hi Greg. The 1217 is for when there’s been no previous repairs attempted. The 1217BS is for second time repairs when a Helicoil or some other type of repair was done and failed leaving the hole bigger.

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