M3 Helicoils | McMaster-Carr

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38 Products

How to Install Helical Inserts

About Helical Insert Length

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.

Inserts that meet DIN 8140 adhere to international standards for dimensions.

For technical drawings and 3-D models, click on a part number.

Metric

Inserts										Through-Hole Taps		Closed-End Hole Taps		Installation Tools		Prong Break-Off Tools
Thread Size	Thread Pitch, mm	Thread Spacing	Installed Lg., mm	Drill Bit Size	For Max. Hole Dia.	Specifications Met	Pkg. Qty.		Pkg.		Each		Each		Each		Each
18-8 Stainless Steel—Right-Hand Threaded
M3	0.5	Coarse	3	3.2 mm	3.2mm	DIN 8140, SAE MA3279-102	10	000000000	000000	000000000	000000	000000000	000000	000000000	0000000	000000000	0000000
M3	0.5	Coarse	4.5	3.2 mm	3.2mm	DIN 8140, SAE MA3279-152	10	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M3	0.5	Coarse	6	3.2 mm	3.2mm	DIN 8140, SAE MA3279-202	10	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M3	0.5	Coarse	7.5	3.2 mm	3.2mm	DIN 8140, SAE MA3279-252	10	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M3	0.5	Coarse	9	3.15 mm	3.15mm	SAE MA3279-302	10	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000

Stainless Steel Helical Inserts for Particle-Free Environments

Made of Nitronic 60 stainless steel, these inserts prevent the screw from binding or sticking without any coating or lubricant that could contaminate particle-free environments. 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. 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.

Metric

Inserts								Through-Hole Taps		Closed-End Hole Taps		Installation Tools		Prong Break-Off Tools
Thread Size	Thread Pitch, mm	Installed Lg., mm	Drill Bit Size, mm	For Max. Hole Dia., mm	Pkg. Qty.		Pkg.		Each		Each		Each		Each
Nitronic 60 Stainless Steel
M3	0.5	3	3.2	3.2	5	000000000	000000	000000000	000000	000000000	000000	000000000	0000000	000000000	0000000
M3	0.5	4.5	3.2	3.2	5	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M3	0.5	6	3.2	3.2	5	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000

Lubricated Stainless Steel Helical Inserts

A dry film keeps the screw from sticking or binding in these inserts during installation. 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. Installation requires a drill bit, a helical insert tap, an installation tool, and a prong break-off tool.

Inserts that meet DIN 8140 adhere to international standards for dimensions.

For technical drawings and 3-D models, click on a part number.

Metric

Inserts									Through-Hole Taps		Closed-End Hole Taps		Installation Tools		Prong Break-Off Tools
Thread Size	Thread Pitch, mm	Installed Lg., mm	Drill Bit Size	For Max. Hole Dia.	Specifications Met	Pkg. Qty.		Pkg.		Each		Each		Each		Each
18-8 Stainless Steel
M3	0.5	3	3.2 mm	3.2mm	DIN 8140, MIL-I-8846, SAE MA3280-102	1	000000000	00000	000000000	000000	000000000	000000	000000000	0000000	000000000	0000000
M3	0.5	4.5	3.2 mm	3.2mm	DIN 8140, MIL-I-8846, SAE MA3280-152	1	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M3	0.5	6	3.2 mm	3.2mm	DIN 8140, MIL-I-8846, SAE MA3280-202	1	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000

Lubricated Stainless Steel Helical Inserts for Dissimilar Metals

Eliminating the need for primer, these inserts are coated to resist corrosion when installed in different materials. They also prevent the screw from sticking or binding in the insert during installation. 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. Installation requires a drill bit, a helical insert tap, an installation tool, and a prong break-off tool.

Inserts that meet DIN 8140 adhere to international standards for dimensions.

For technical drawings and 3-D models, click on a part number.

Metric

Inserts									Through-Hole Taps		Closed-End Hole Taps		Installation Tools		Prong Break-Off Tools
Thread Size	Thread Pitch, mm	Installed Lg., mm	Drill Bit Size	For Max. Hole Dia.	Specifications Met	Pkg. Qty.		Pkg.		Each		Each		Each		Each
18-8 Stainless Steel
M3	0.5	4.5	3.2 mm	3.2mm	DIN 8140	1	000000000	00000	000000000	000000	000000000	000000	000000000	0000000	000000000	0000000
M3	0.5	6	3.2 mm	3.2mm	DIN 8140	1	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000

Nickel Alloy Helical Inserts

Made of nickel alloy, these inserts are more resistant to acids and salt water than stainless steel inserts. 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. 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.

Metric

Inserts								Through-Hole Taps		Closed-End Hole Taps		Installation Tools		Prong Break-Off Tools
Thread Size	Thread Pitch, mm	Installed Lg., mm	Drill Bit Size	For Max. Hole Dia.	Pkg. Qty.		Pkg.		Each		Each		Each		Each
Nickel Alloy
M3	0.5	3	3.2 mm	3.2 mm	1	000000000	00000	000000000	000000	000000000	000000	000000000	0000000	000000000	0000000
M3	0.5	6	3.2 mm	3.2 mm	1	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000

Stainless Steel Screw-Locking Helical Inserts

A distorted thread grips the screw to resist loosening. 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.

Inserts that meet DIN 8140 adhere to international standards for dimensions.

For technical drawings and 3-D models, click on a part number.

Metric

Inserts										Through-Hole Taps		Closed-End Hole Taps		Installation Tools		Prong Break-Off Tools
Thread Size	Thread Pitch, mm	Thread Spacing	Installed Lg., mm	Drill Bit Size	For Max. Hole Dia.	Specifications Met	Pkg. Qty.		Pkg.		Each		Each		Each		Each
18-8 Stainless Steel
M3	0.5	Coarse	3	3.2 mm	3.2mm	DIN 8140, SAE MA3329-102	10	000000000	000000	000000000	000000	000000000	000000	000000000	0000000	000000000	0000000
M3	0.5	Coarse	4.5	3.2 mm	3.2mm	DIN 8140, SAE MA3329-152	10	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M3	0.5	Coarse	6	3.2 mm	3.2mm	DIN 8140, SAE MA3329-202	10	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M3	0.5	Coarse	7.5	3.2 mm	3.2mm	DIN 8140, SAE MA3329-252	1	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000

Stainless Steel Helical Inserts without Prong

Without a prong to break off and retrieve, these inserts are often used where debris could cause damage. Also known as Heli-Coil inserts, they have coils that expand once installed to securely anchor the insert. Installation requires a drill bit, a helical insert tap, and an installation tool.

For technical drawings and 3-D models, click on a part number.

Metric

Inserts								Through-Hole Taps		Closed-End Hole Taps		Installation Tools		Extraction Tools
Thread Size	Thread Pitch, mm	Installed Lg., mm	Drill Bit Size	For Max. Hole Dia.	Pkg. Qty.		Pkg.		Each		Each		Each		Each
18-8 Stainless Steel
M3	0.5	3	3.2 mm	3.2mm	10	000000000	00000	000000000	000000	000000000	000000	000000000	0000000	000000000	0000000
M3	0.5	4.5	3.2 mm	3.2mm	10	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M3	0.5	6	3.2 mm	3.2mm	10	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000

Screw-Locking Helical Inserts without Prong

A distorted thread grips the screw to resist loosening. Without a prong to break off and retrieve, these inserts are often used where debris could cause damage. Also known as Heli-Coil inserts, they have coils that expand once installed to securely anchor the insert. Installation requires a drill bit, a helical insert tap, and an installation tool.

Inserts that meet DIN 8140 adhere to international standards for dimensions.

For technical drawings and 3-D models, click on a part number.

Metric

Inserts									Through-Hole Taps		Closed-End Hole Taps		Installation Tools
Thread Size	Thread Pitch, mm	Installed Lg., mm	Drill Bit Size	For Max. Hole Dia.	Specifications Met	Pkg. Qty.		Pkg.		Each		Each		Each
18-8 Stainless Steel
M3	0.5	3	3.2 mm	3.2mm	NA0276M3-L10	10	000000000	00000	000000000	000000	000000000	000000	000000000	0000000
M3	0.5	4.5	3.2 mm	3.2mm	NA0276M3-L15	10	000000000	0000	000000000	00000	000000000	00000	000000000	000000
M3	0.5	6	3.2 mm	3.2mm	DIN 8140, NA0276M3-L20	10	000000000	0000	000000000	00000	000000000	00000	000000000	000000

Helical Inserts with Installation Tools

Shown with Five Inserts and Drill Bit

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.

Metric

18-8 Stainless Steel—Right-Hand Threaded
Thread Size	Thread Pitch, mm	Thread Spacing	Installed Lg., mm	Drill Bit Size	For Max. Hole Dia.	No. of Inserts Included	Includes		Each
M3	0.5	Coarse	3	3.15 mm	1/8"	10	Drill Bit, Through-Hole Tap, Installation Tool	000000000	0000000
M3	0.5	Coarse	4.5	3.15 mm	1/8"	10	Drill Bit, Through-Hole Tap, Installation Tool	000000000	000000
M3	0.5	Coarse	6	3.15 mm	1/8"	10	Drill Bit, Through-Hole Tap, Installation Tool	000000000	000000

Helical Insert Assortments with Installation Tools

Assortments include various sizes of helical inserts and a tap, a drill bit, and an installation tool for each thread size. Also known as Heli-Coil inserts, the 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.

Metric
Includes	No. of Inserts Included	Thread Spacing	Drill Bit Size	For Max. Hole Dia.		Each
18-8 Stainless Steel
M3×0.5 mm Thread × 3 mm Installed Lg. (12 Each) M3×0.5 mm Thread × 4.5 mm Installed Lg. (12 Each) M3×0.5 mm Thread × 6 mm Installed Lg. (12 Each) Drill Bit Through-Hole Tap Installation Tool	36	Coarse	1/8"	1/8"	000000000	0000000

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.

For technical drawings and 3-D models, click on a part number.

Metric

For Thread
Size	Pitch, mm	Style		Each
For Right-Hand Thread
M3	0.5	E	000000000	0000000

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.

Metric

For Thread Size		Each
M3, M3.5	000000000	0000000

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
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	000000

Installation Tools for Helical Inserts without Prong

Screw an insert onto these tools and drive them a quarter to half-turn below the material’s surface.

Replacement tips (sold separately) include one installation tip, two pins, and two springs.

Metric

Installation Tools
For Thread					Replacement Tips
Size	Pitch, mm	Style		Each		Each
M3	0.5	B	000000000	0000000	000000000	0000000

Extraction Tools for Helical Inserts without Prong

Thread these tools into an insert and turn counterclockwise to extract.

Tools with a hollow handle store the tip.

Replacement tips (sold separately) come with one removal tip, two pins, and two springs.

Metric

Extraction Tools			Replacement Tips
For Thread Size		Each		Each
M3	000000000	0000000	000000000	000000