M8 Helicoils | McMaster-Carr

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	System of Measurement System of Measurement

Metric

	Thread Size Thread Size	Show

	Thread Size Thread Size	Hide

	Thread Pitch Thread Pitch

	Installed Length Installed Length

5 mm to 9.9 mm

10 mm to 19.9 mm

20 mm to 24.9 mm

	Material Material

Stainless Steel

Nickel

	For Minimum Material Thickness For Minimum Material Thickness

5 mm to 9.9 mm

10 mm to 19.9 mm

20 mm to 24.9 mm

	Number of Inserts Included Number of Inserts Included

	Helical Insert Style Helical Insert Style

With Prong

Without Prong

	For Maximum Hole Diameter For Maximum Hole Diameter

0.125" to 0.249"

0.25" to 0.499"

7 mm to 9.9 mm

	Drill Bit Size Drill Bit Size

	Thread Spacing Thread Spacing

Coarse

Fine

	Thread Type Thread Type

Metric

	For Tap Type For Tap Type

Helical

	Thread Direction Thread Direction

	Right Hand

	RoHS (Restriction of Hazardous Substances) RoHS (Restriction of Hazardous Substances)

RoHS Compliant

	Passivation Passivation

Not Passivated

	Tensile Strength Tensile Strength

200,000 psi

	Specifications Met Specifications Met

	DFARS (Defense Acquisition Regulations Supplement) DFARS (Defense Acquisition Regulations Supplement)

DFARS Specialty Metals
COTS-Exempt

DFARS Specialty Metals
Compliant

	REACH (Registration, Evaluation, Authorization and Restriction of Chemicals) REACH (Registration, Evaluation, Authorization and Restriction of Chemicals)

REACH Compliant

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49 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
M8	1.25	Coarse	8	8.4 mm	8.4mm	DIN 8140, SAE MA3279-109	10	000000000	00000	000000000	000000	000000000	000000	000000000	0000000	000000000	0000000
M8	1.25	Coarse	12	8.4 mm	8.4mm	DIN 8140, SAE MA3279-159	10	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M8	1.25	Coarse	16	8.4 mm	8.4mm	DIN 8140, SAE MA3279-209	10	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M8	1.25	Coarse	20	8.4 mm	8.4mm	DIN 8140, SAE MA3279-259	10	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M8	1.25	Coarse	24	8.3 mm	8.3mm	SAE MA3279-309	5	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M8	1	Fine	8	8.3 mm	8.3mm	DIN 8140, SAE MA3279-108	10	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M8	1	Fine	12	8.3 mm	8.3mm	DIN 8140, SAE MA3279-158	10	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M8	1	Fine	16	8.3 mm	8.3mm	DIN 8140, SAE MA3279-208	10	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M8	1	Fine	20	8.3 mm	8.3mm	SAE MA3279-258	10	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M8	1	Fine	24	8.3 mm	8.3mm	SAE MA3279-308	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
M8	1.25	8	8.4	8.4	5	000000000	000000	000000000	000000	000000000	000000	000000000	0000000	000000000	0000000
M8	1.25	12	8.4	8.4	5	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M8	1.25	16	8.4	8.4	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
M8	1.25	8	8.4 mm	8.4mm	MIL-I-8846, SAE MA3280-109	1	000000000	00000	000000000	000000	000000000	000000	000000000	0000000	000000000	0000000
M8	1.25	12	8.4 mm	8.4mm	DIN 8140, MIL-I-8846, SAE MA3280-159	1	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M8	1.25	16	8.4 mm	8.4mm	DIN 8140, MIL-I-8846, SAE MA3280-209	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
M8	1.25	8	8.4 mm	8.4mm	DIN 8140	1	000000000	00000	000000000	000000	000000000	000000	000000000	0000000	000000000	0000000
M8	1.25	12	8.4 mm	8.4mm	DIN 8140	1	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M8	1.25	16	8.4 mm	8.4mm	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
M8	1.25	8	8.4 mm	8.4 mm	1	000000000	00000	000000000	000000	000000000	000000	000000000	0000000	000000000	0000000
M8	1.25	12	8.4 mm	8.4 mm	1	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M8	1.25	16	8.4 mm	8.4 mm	1	000000000	00000	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
M8	1.25	Coarse	8	8.4 mm	8.4mm	DIN 8140, SAE MA3329-109	10	000000000	000000	000000000	000000	000000000	000000	000000000	0000000	000000000	0000000
M8	1.25	Coarse	12	8.4 mm	8.4mm	DIN 8140, SAE MA3329-159	10	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M8	1.25	Coarse	16	8.4 mm	8.4mm	DIN 8140, SAE MA3329-209	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M8	1.25	Coarse	20	8.4 mm	8.4mm	SAE MA3329-259	1	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M8	1	Fine	8	8.3 mm	8.3mm	DIN 8140, SAE MA3329-108	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M8	1	Fine	12	8.3 mm	8.3mm	DIN 8140, SAE MA3329-158	5	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M8	1	Fine	16	8.3 mm	8.3mm	SAE MA3329-208	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000

Lubricated Stainless Steel Screw-Locking Helical Inserts

A dry film keeps the screw from sticking or binding in these inserts during installation, yet a distorted thread grips the screw to resist loosening. 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
M8	1.25	8	8.4 mm	8.4mm	DIN 8140, SAE MA3330-109	1	000000000	00000	000000000	000000	000000000	000000	000000000	0000000	000000000	0000000
M8	1.25	12	8.4 mm	8.4mm	DIN 8140, SAE MA3330-159	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000	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
M8	1.25	Coarse	8	21/64"	21/64"	10	Drill Bit, Through-Hole Tap, Installation Tool	000000000	0000000
M8	1.25	Coarse	12	21/64"	21/64"	10	Drill Bit, Through-Hole Tap, Installation Tool	000000000	00000
M8	1.25	Coarse	16	21/64"	21/64"	10	Drill Bit, Through-Hole Tap, Installation Tool	000000000	000000
M8	1	Fine	12	21/64"	21/64"	10	Drill Bit, Through-Hole Tap, Installation Tool	000000000	00000

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
M5×0.8 mm Thread × 7.5 mm Installed Lg. (12 Each) M6×1 mm Thread × 9 mm Installed Lg. (12 Each) M8×1.25 mm Thread × 12 mm Installed Lg. (12 Each) M10×1.5 mm Thread × 15 mm Installed Lg. (12 Each) Drill Bits Through-Hole Taps Installation Tools	48	Coarse	13/64" 1/4" 21/64" 13/32"	13/64" 1/4" 21/64" 13/32"	000000000	0000000
M8×1.25 mm Thread × 8 mm Installed Lg. (6 Each) M8×1.25 mm Thread × 12 mm Installed Lg. (6 Each) M8×1.25 mm Thread × 16 mm Installed Lg. (6 Each) Drill Bit Through-Hole Tap Installation Tool	18	Coarse	21/64"	21/64"	000000000	00000

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.

Add an extraction tool to remove these inserts.

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
M8	1.25	8	8.4 mm	8.4mm	10	000000000	00000	000000000	000000	000000000	000000	000000000	0000000	000000000	0000000
M8	1.25	12	8.4 mm	8.4mm	10	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M8	1.25	16	8.4 mm	8.4mm	10	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000