Heli-Coil® vs. Keensert® vs. Keysert® vs. Acme: Comparing Threaded Inserts
Acme Threaded Inserts are often compared to Keensert® inserts and Heli-Coil® inserts. (Keensert is a registered trademark of Huck Patents, Inc., Heli-Coil is a registered trademark of Emhart® Teknologies, Inc). A product similar to Keensert® inserts is the Keysert® insert. Keysert is a registered trademark of Alcoa Fastening Systems (Huck Patents, Inc. is listed as latest owner on US Trademark site.) All of these products are used for thread repair or to bolster the strength of a weaker parent metal, like aluminum.
The largest differences between the inserts are in strength and ease of installation. Heli-Coil® inserts are precision formed thread coils made of stainless steel wire. Installing a Heli-Coil® insert involves tapping (or re-tapping if a thread repair job) a hole, lining up the Heli-Coil® thread with the tapped hole and using a special use tool to install. Cross threading can be a problem if the installer is inexperienced. Heli-Coil® inserts have less pull-out strength than Acme threaded inserts or Keensert®-style products because they are wound wire versus a solid metal bushing.
Both Acme Threaded Inserts and Keensert®-style inserts are easy to install with standard drills and taps. The inserts are placed by the installer's fingers, without the need of a pre-winder tool. Accidental cross-threading is nearly impossible.
When an Acme or Keensert®-style insert needs to be removed, the material between the keys is drilled out with a standard drill, the keys are bent inward to break off, and a standard screw extractor is used. If a removed insert needs to be replaced, the new insert can be placed into the original tapped hole.
Acme Threaded Inserts have some advantages over similar Keensert® inserts:
- Acme inserts are available in solid carbon steel
- Acme threaded inserts are available in solid metric
- Acme inserts are made in the USA
- Acme inserts are DFARS compliant
- Acme offers more Kit Styles versus Keensert® inserts
- Acme offers more metric-sized inserts versus Keensert® inserts
- Acme metric inserts have metric threads both internally and externally
|Acme Threaded Inserts||Keensert® Inserts||Heli-Coil® Inserts|
|Special Installation Tools Required?||No, Standard Drills and Taps are Used||No, Standard Drills and Taps are Used||Yes, Special Purpose Drills, Taps and Pre-Winder Tool Needed|
|Easy to Install?||Yes||Yes||Takes Some Practice|
|Avoids Potential Tang Break Off Issues?||Yes||Yes||No|
|Superior Pullout Strength from Solid Bushing and Locking Key?||Yes||Yes||No|
|Positive Mechanical Lock to Prohibit Rotation?||Yes||Yes||No|
|Difficult to Cross Thread by MIstake During Installation?||Yes||Yes||No|
|Used in Nearly Any Base Material(Aluminum, Magnesium, Plastics, Steel, Cast Iron)?||Yes||Yes||?|
|Easy to Remove?||Yes||Yes||Yes|
|New Insert can be Used in Same Hole After Removal of Previous Insert?||Yes||Yes||Yes|
|Solid Carbon Steel Inserts Available?||Yes||No||No|
|Solid Metric Inserts have Both Internal and External Metric Threads?||Yes||No||NA|
|Greater Variety of Solid Insert Kit Styles?||Yes||No||NA|
|Greater Number of Solid Insert Metric Sizes?||Yes||No||NA|
|Made in U.S.A.?||Yes||?||?|