How to Install Helical Inserts
More
About Helical Insert Length
More
Stainless Steel Helical Inserts
Also known as Heli-Coil inserts, these inserts have coils that expand once installed to securely anchor the insert. All have a prong for ease of installation. An installation tool grips the prong and reduces the coil diameter, enabling the insert to fit in tapped holes. Remove the prong to insert the screw. Installation requires a drill bit, a helical insert tap, an installation tool, and a prong break-off tool.
For technical drawings and 3-D models, click on a part number.
Inserts | Through-Hole Taps | Installation Tools | Prong Break-Off Tools | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Thread Size  | Installed Lg. | Drill Bit Size | For Max. Hole Dia. | Pkg. Qty. | Pkg. | Each | Each | Each | ||||
18-8 Stainless Steel—Left-Hand Threaded | ||||||||||||
| 1/4"-20 | 3/8" | H | 0.266" | 1 | 000000000 | 00000 | 000000000 | 000000 | 000000000 | 000000 | 000000000 | 0000000 |
| 1/4"-28 | 3/8" | 6.7 mm | 6.7mm | 1 | 000000000 | 0000 | 000000000 | 00000 | 000000000 | 00000 | 000000000 | 000000 |
| 5/16"-18 | 0.469" | Q | 0.332" | 1 | 000000000 | 0000 | 000000000 | 00000 | 000000000 | 00000 | 000000000 | 000000 |
| 5/16"-24 | 0.469" | 21/64" | 21/64" | 1 | 000000000 | 0000 | 000000000 | 00000 | 000000000 | 00000 | 000000000 | 000000 |
| 3/8"-16 | 0.562" | X | 0.397" | 1 | 000000000 | 0000 | 000000000 | 00000 | 000000000 | 00000 | 000000000 | 000000 |
| 3/8"-24 | 0.562" | 25/64" | 25/64" | 1 | 000000000 | 0000 | 000000000 | 00000 | 000000000 | 00000 | 000000000 | 000000 |
| 1/2"-13 | 3/4" | 17/32" | 17/32" | 1 | 000000000 | 0000 | 000000000 | 00000 | 000000000 | 00000 | 000000000 | 000000 |
| 1/2"-20 | 3/4" | 33/64" | 33/64" | 1 | 000000000 | 0000 | 000000000 | 00000 | 000000000 | 00000 | 000000000 | 000000 |
| 5/8"-11 | 0.938" | 21/32" | 21/32" | 1 | 000000000 | 0000 | 000000000 | 000000 | 000000000 | 00000 | 000000 | 00 |
| 5/8"-18 | 0.938" | 41/64" | 41/64" | 1 | 000000000 | 0000 | 000000000 | 000000 | 000000000 | 00000 | 000000 | 00 |
| 3/4"-10 | 1 1/8" | 25/32" | 25/32" | 1 | 000000000 | 00000 | 000000000 | 000000 | 000000000 | 00000 | 000000 | 00 |
Helical Inserts with Installation Tools
Inserts come with a through-hole tap and installation tool. Also known as Heli-Coil inserts, they have coils that expand once installed to securely anchor the insert. All have a prong for ease of installation. An installation tool grips the prong and reduces the coil diameter, enabling the insert to fit in tapped holes. Remove the prong to insert the screw.
For technical drawings and 3-D models, click on a part number.
| Thread Size | Installed Lg. | Drill Bit Size | For Max. Hole Dia. | No. of Inserts Included | Includes | Each | |
18-8 Stainless Steel—Left-Hand Threaded | |||||||
|---|---|---|---|---|---|---|---|
| 1/4"-20 | 3/8" | 17/64" | 17/64" | 6 | Through-Hole Tap, Installation Tool | 000000000 | 000000 |
| 1/4"-28 | 3/8" | 17/64" | 17/64" | 6 | Through-Hole Tap, Installation Tool | 000000000 | 00000 |
| 5/16"-18 | 0.469" | 21/64" | 21/64" | 6 | Through-Hole Tap, Installation Tool | 000000000 | 000000 |
| 5/16"-24 | 0.469" | 21/64" | 21/64" | 6 | Through-Hole Tap, Installation Tool | 000000000 | 000000 |
| 3/8"-16 | 0.562" | 25/64" | 25/64" | 6 | Through-Hole Tap, Installation Tool | 000000000 | 000000 |
| 3/8"-24 | 0.562" | 25/64" | 25/64" | 6 | Through-Hole Tap, Installation Tool | 000000000 | 000000 |
| 1/2"-13 | 3/4" | 17/32" | 17/32" | 4 | Through-Hole Tap, Installation Tool | 000000000 | 000000 |
| 1/2"-20 | 3/4" | 33/64" | 33/64" | 4 | Through-Hole Tap, Installation Tool | 000000000 | 000000 |
| 5/8"-11 | 0.938" | 21/32" | 21/32" | 2 | Through-Hole Tap, Installation Tool | 000000000 | 000000 |
| 5/8"-18 | 0.938" | 41/64" | 41/64" | 2 | Through-Hole Tap, Installation Tool | 000000000 | 000000 |
| 3/4"-10 | 1 1/8" | 25/32" | 25/32" | 2 | Through-Hole Tap, Installation Tool | 000000000 | 000000 |
Installation Tools for Helical Inserts
Screw an insert onto these tools and drive them a quarter to half-turn below the material’s surface. They’re compatible with helical inserts that have a prong.
Prong Break-Off Tools for Helical Inserts
Place the tip of these tools into installed inserts and push down to trigger the spring-loaded punch to break off the prong.
For technical drawings and 3-D models, click on a part number.
| For Thread Size | Each | |
| 1-64 | 000000000 | 0000000 |
| 2-56, 3-48, 3-56 | 000000000 | 000000 |
| 4-40, 4-48, 5-40 | 000000000 | 000000 |
| 6-32, 6-40 | 000000000 | 00000 |
| 8-32, 8-36 | 000000000 | 00000 |
| 10-24, 10-32, 12-24 | 000000000 | 000000 |
| 1/4"-20, 1/4"-28 | 000000000 | 000000 |
| 5/16"-18 | 000000000 | 000000 |
| 5/16"-24 | 000000000 | 000000 |
| 3/8"-16 | 000000000 | 000000 |
| 3/8"-24 | 000000000 | 000000 |
| 7/16"-14 | 000000000 | 000000 |
| 7/16"-20 | 000000000 | 000000 |
| 1/2"-13 | 000000000 | 000000 |
| 1/2"-20 | 000000000 | 000000 |
Extraction Tools for Helical Inserts
Place the tip of these tools into an insert and strike a light blow to the tool’s head. Then turn the tools counterclockwise with pressure to extract the insert.
| For Thread Size | Each | |
| 1-64, 1-72, M2 | 000000000 | 0000000 |
| 2-56, 2-64, M2.2 | 000000000 | 00000 |
| 3-48, 3-56, 4-40, 4-48, 5-40, 5-44, 6-32, 6-40, 8-32, 8-36, 8-40, M2.5, M3, M3.5, M4 | 000000000 | 00000 |
| 10-24, 10-32, 12-24, 12-28, 1/4"-20, 1/4"-28, 1/4"-32, 1/4"-80, 5/16"-18, 5/16"-24, 5/16"-32, 3/8"-16, 3/8"-24, M5, M6, M7, M8, M10 | 000000000 | 00000 |
| 7/16"-14, 7/16"-20, 1/2"-13, 1/2"-20, 1/2"-28, 9/16"-12, 9/16"-18, 5/8"-11, 5/8"-18, 5/8"-24, 3/4"-10, 3/4"-16, 3/4"-20, 7/8"-9, 7/8"-14, 7/8"-20, 1"-8, 1"-12, 1"-14, M12, M14, M16, M18, M20, M22, M24 | 000000000 | 00000 |
| 1 1/8"-7, 1 1/8"-12, 1 1/4"-7, 1 1/4"-8, 1 1/4"-12, 1 3/8"-6, 1 3/8"-12, 1 1/2"-6, 1 1/2"-8, 1 1/2"-12, M27, M30, M36, M39 | 000000000 | 000000 |
Taps for Helical Inserts
Add threads to holes in preparation for installing helical inserts. These taps are made of uncoated high-speed steel and are for use on most metal and plastic. The square shank is compatible with tap wrenches and tap holders for drill presses and milling machines.
Plug-chamfer taps are a versatile choice for most tapping applications. With 3-5 chamfered cutting threads, they require moderate torque and are often used for start-to-finish tapping of through holes and closed-end holes. When using them to tap closed-end holes, be sure to leave sufficient space at the bottom for chips to accumulate.
For technical drawings and 3-D models, click on a part number.
Drill Bit | Plug Chamfer | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| For Insert Thread Size | Thread Lg. | Overall Lg. | Max. Tapping Dp. | Size | Decimal Size Equivalent | No. of Flutes | For Insert Thread Type | Pitch Dia. Limit | Each | |
Uncoated High-Speed Steel | ||||||||||
| 1/4"-20 | 1 1/8" | 2 23/32" | 1 1/8" | H | 0.266" | 4 | UNC | H2 | 000000000 | 000000 |
| 1/4"-28 | 1 1/8" | 2 23/32" | 1 1/8" | 6.7 mm | 0.2637" | 4 | UNF | H2 | 000000000 | 00000 |
| 5/16"-18 | 1 1/4" | 2 15/16" | 1 1/4" | Q | 0.332" | 4 | UNC | H3 | 000000000 | 00000 |
| 5/16"-24 | 1 1/4" | 2 15/16" | 1 1/4" | 21/64" | 0.3281" | 4 | UNF | H4 | 000000000 | 00000 |
| 3/8"-16 | 1 21/32" | 3 3/8" | 1 21/32" | X | 0.397" | 4 | UNC | H3 | 000000000 | 00000 |
| 3/8"-24 | 1 7/16" | 3 5/32" | 1 7/16" | 25/64" | 0.3906" | 4 | UNF | H3 | 000000000 | 00000 |
| 1/2"-13 | 1 13/16" | 3 13/16" | 1 13/16" | 17/32" | 0.5313" | 4 | UNC | H3 | 000000000 | 00000 |
| 1/2"-20 | 1 21/32" | 3 19/32" | 1 21/32" | 33/64" | 0.5156" | 4 | UNF | H5 | 000000000 | 00000 |
| 5/8"-11 | 1 13/16" | 4 1/4" | 1 13/16" | 21/32" | 0.6563" | 4 | UNC | H3 | 000000000 | 000000 |
| 5/8"-18 | 1 13/16" | 4 1/32" | 1 13/16" | 41/64" | 0.6406" | 4 | UNF | H3 | 000000000 | 000000 |
| 3/4"-10 | 2 7/32" | 4.667" | 2 7/32" | 25/32" | 0.7813" | 4 | UNC | H5 | 000000000 | 000000 |