Locking Helical Inserts | McMaster-Carr

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How to Install Helical Inserts

About Helical Insert Length

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.

Inch

Inserts								Through-Hole Taps		Closed-End Hole Taps		Installation Tools		Prong Break-Off Tools
Thread Size	Installed Lg.	Drill Bit Size	For Max. Hole Dia.	Specifications Met	Pkg. Qty.		Pkg.		Each		Each		Each		Each
18-8 Stainless Steel
1-64	0.073"	No. 46	0.081"	__	5	000000000	000000	000000000	000000	000000000	000000	000000000	0000000	000000000	0000000
1-64	0.11"	No. 46	0.081"	__	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
2-56	0.086"	No. 41	0.096"	MS21209C0210, NASM21209	10	000000000	0000	000000000	00000	000000000	00000	000000000	00000	000000000	000000
2-56	0.129"	No. 41	0.096"	MS21209C0215, NASM21209	10	000000000	0000	000000000	00000	000000000	00000	000000000	00000	000000000	000000
2-56	0.172"	No. 41	0.096"	MS21209C0220, NASM21209	10	000000000	0000	000000000	00000	000000000	00000	000000000	00000	000000000	000000
2-56	0.215"	No. 41	0.096"	MS21209C0225, NASM21209	1	000000000	0000	000000000	00000	000000000	00000	000000000	00000	000000000	000000
3-48	0.099"	7/64"	7/64"	MS21209C0310, NASM21209	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
3-48	0.148"	7/64"	7/64"	MS21209C0315, NASM21209	10	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
3-56	0.099"	No. 36	0.1065"	MS21209F0310, NASM21209	10	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
3-56	0.148"	No. 36	0.1065"	MS21209F0315, NASM21209	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
4-40	0.112"	No. 31	0.12"	MS21209C0410, NASM21209	10	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
4-40	0.168"	No. 31	0.12"	MS21209C0415, NASM21209	10	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
4-40	0.224"	No. 31	0.12"	MS21209C0420, NASM21209	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
4-40	0.28"	No. 31	0.12"	MS21209C0425, NASM21209	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
4-40	0.336"	No. 31	0.12"	MS21209C0430, NASM21209	1	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
4-48	0.112"	No. 31	0.12"	MS21209F0410, NASM21209	10	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
4-48	0.168"	No. 31	0.12"	MS21209F0415, NASM21209	10	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
5-40	1/8"	No. 29	0.136"	MS21209C0510, NASM21209	10	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
5-40	0.188"	No. 29	0.136"	MS21209C0515, NASM21209	10	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
5-40	1/4"	No. 29	0.136"	MS21209C0520, NASM21209	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
6-32	0.138"	No. 25	0.1495"	MS21209C0610, NASM21209	10	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	00000
6-32	0.207"	No. 25	0.1495"	MS21209C0615, NASM21209	10	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	00000
6-32	0.276"	No. 25	0.1495"	MS21209C0620, NASM21209	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	00000
6-32	0.345"	No. 25	0.1495"	MS21209C0625, NASM21209	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	00000
6-32	0.414"	No. 25	0.1495"	MS21209C0630, NASM21209	1	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	00000
6-40	0.138"	No. 25	0.1495"	MS21209F0610, NASM21209	10	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	00000
6-40	0.207"	No. 25	0.1495"	MS21209F0615, NASM21209	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	00000
6-40	0.276"	No. 25	0.1495"	MS21209F0620, NASM21209	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	00000
8-32	0.164"	No. 16	0.177"	MS21209C0810, NASM21209	10	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	00000
8-32	0.246"	No. 16	0.177"	MS21209C0815, NASM21209	10	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	00000
8-32	0.328"	No. 16	0.177"	MS21209C0820, NASM21209	10	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	00000
8-32	0.41"	No. 16	0.177"	MS21209C0825, NASM21209	1	000000000	000	000000000	00000	000000000	00000	000000000	000000	000000000	00000
8-32	0.492"	No. 16	0.177"	MS21209C0830, NASM21209	1	000000000	000	000000000	00000	000000000	00000	000000000	000000	000000000	00000
8-36	0.164"	No. 16	0.177"	MS21209F0810, NASM21209	10	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	00000
8-36	0.246"	No. 16	0.177"	MS21209F0815, NASM21209	10	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	00000
8-36	0.328"	No. 16	0.177"	MS21209F0820, NASM21209	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	00000
10-24	0.19"	No. 5	0.2055"	MS21209C1-10, NASM21209	10	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
10-24	0.285"	No. 5	0.2055"	MS21209C1-15, NASM21209	10	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
10-24	0.38"	No. 5	0.2055"	MS21209C1-20, NASM21209	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
10-24	0.475"	No. 5	0.2055"	MS21209C1-25, NASM21209	1	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
10-32	0.19"	13/64"	13/64"	MS21209F1-10	10	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
10-32	0.285"	13/64"	13/64"	MS21209F1-15, NASM21209	10	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
10-32	0.38"	13/64"	13/64"	MS21209F1-20, NASM21209	10	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
10-32	0.475"	13/64"	13/64"	MS21209F1-25, NASM21209	1	000000000	000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
10-32	0.57"	13/64"	13/64"	MS21209F1-30, NASM21209	1	000000000	000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
12-24	0.216"	No. 1	0.228"	MS21209C2-10, NASM21209	10	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
12-24	0.324"	No. 1	0.228"	MS21209C2-15, NASM21209	10	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
1/4"-20	1/4"	H	0.266"	MS21209C4-10, NASM21209	10	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
1/4"-20	3/8"	H	0.266"	MS21209C4-15, NASM21209	10	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
1/4"-20	1/2"	H	0.266"	MS21209C4-20, NASM21209	10	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
1/4"-20	5/8"	H	0.266"	MS21209C4-25, NASM21209	1	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
1/4"-20	3/4"	H	0.266"	MS21209C4-30, NASM21209	1	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
1/4"-28	1/4"	6.7 mm	6.7mm	MS21209F4-10, NASM21209	10	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
1/4"-28	3/8"	6.7 mm	6.7mm	MS21209F4-15, NASM21209	10	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
1/4"-28	1/2"	6.7 mm	6.7mm	MS21209F4-20, NASM21209	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
1/4"-28	5/8"	6.7 mm	6.7mm	MS21209F4-25, NASM21209	1	000000000	000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
5/16"-18	0.312"	Q	0.332"	MS21209C5-10, NASM21209	10	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
5/16"-18	0.469"	Q	0.332"	MS21209C5-15, NASM21209	10	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
5/16"-18	5/8"	Q	0.332"	MS21209C5-20, NASM21209	1	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
5/16"-24	0.312"	21/64"	21/64"	MS21209F5-10, NASM21209	10	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
5/16"-24	0.469"	21/64"	21/64"	MS21209F5-15, NASM21209	10	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
5/16"-24	5/8"	21/64"	21/64"	MS21209F5-20, NASM21209	1	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
5/16"-24	0.781"	21/64"	21/64"	MS21209F5-25, NASM21209	1	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
3/8"-16	3/8"	X	0.397"	MS21209C6-10, NASM21209	10	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
3/8"-16	0.562"	X	0.397"	MS21209C6-15, NASM21209	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
3/8"-16	3/4"	X	0.397"	MS21209C6-20, NASM21209	1	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
3/8"-24	3/8"	25/64"	25/64"	MS21209F6-10, NASM21209	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
3/8"-24	0.562"	25/64"	25/64"	MS21209F6-15, NASM21209	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
3/8"-24	3/4"	25/64"	25/64"	MS21209F6-20, NASM21209	1	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
3/8"-24	0.938"	25/64"	25/64"	MS21209F6-25, NASM21209	1	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
7/16"-14	0.438"	29/64"	29/64"	MS21209C7-10, NASM21209	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
7/16"-14	0.656"	29/64"	29/64"	MS21209C7-15, NASM21209	5	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
7/16"-14	7/8"	29/64"	29/64"	MS21209C7-20, NASM21209	1	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
7/16"-20	0.438"	29/64"	29/64"	MS21209F7-10, NASM21209	5	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
7/16"-20	0.656"	29/64"	29/64"	MS21209F7-15, NASM21209	5	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
7/16"-20	7/8"	29/64"	29/64"	MS21209F7-20, NASM21209	1	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
1/2"-13	1/2"	17/32"	17/32"	MS21209C8-10, NASM21209	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
1/2"-13	3/4"	17/32"	17/32"	MS21209C8-15, NASM21209	5	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
1/2"-13	1"	17/32"	17/32"	MS21209C8-20, NASM21209	1	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
1/2"-13	1 1/4"	17/32"	17/32"	MS21209C8-25, NASM21209	1	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
1/2"-20	1/2"	33/64"	33/64"	MS21209F8-10, NASM21209	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
1/2"-20	3/4"	33/64"	33/64"	MS21209F8-15, NASM21209	5	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
1/2"-20	1"	33/64"	33/64"	MS21209F8-20, NASM21209	1	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
1/2"-20	1 1/4"	33/64"	33/64"	MS21209F8-25, NASM21209	1	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
9/16"-12	0.562"	19/32"	19/32"	MS21209C9-10, NASM21209	1	000000000	0000	000000000	00000	000000000	000000	000000000	00000	000000	00
9/16"-12	0.844"	19/32"	19/32"	MS21209C9-15, NASM21209	1	000000000	0000	000000000	00000	000000000	000000	000000000	00000	000000	00
9/16"-18	0.562"	37/64"	37/64"	MS21209F9-10, NASM21209	1	000000000	0000	000000000	00000	000000000	000000	000000000	000000	000000	00
9/16"-18	0.844"	37/64"	37/64"	MS21209F9-15, NASM21209	1	000000000	0000	000000000	00000	000000000	000000	000000000	000000	000000	00
5/8"-11	5/8"	21/32"	21/32"	MS21209C1010, NASM21209	1	000000000	0000	000000000	00000	000000000	000000	000000000	00000	000000	00
5/8"-11	0.938"	21/32"	21/32"	MS21209C1015, NASM21209	1	000000000	0000	000000000	00000	000000000	000000	000000000	00000	000000	00
5/8"-11	1 1/4"	21/32"	21/32"	MS21209C1020, NASM21209	1	000000000	0000	000000000	00000	000000000	000000	000000000	00000	000000	00
5/8"-18	5/8"	41/64"	41/64"	MS21209F1010, NASM21209	1	000000000	0000	000000000	000000	000000000	000000	000000000	000000	000000	00
5/8"-18	0.938"	41/64"	41/64"	MS21209F1015, NASM21209	1	000000000	0000	000000000	000000	000000000	000000	000000000	000000	000000	00
3/4"-10	3/4"	25/32"	25/32"	MS21209C1210, NASM21209	1	000000000	0000	000000000	000000	000000000	000000	000000000	00000	000000	00
3/4"-10	1 1/8"	25/32"	25/32"	MS21209C1215, NASM21209	1	000000000	0000	000000000	000000	000000000	000000	000000000	00000	000000	00
3/4"-10	1 1/2"	25/32"	25/32"	MS21209C1220, NASM21209	1	000000000	0000	000000000	000000	000000000	000000	000000000	00000	000000	00
3/4"-16	3/4"	49/64"	49/64"	MS21209F1210, NASM21209	1	000000000	0000	000000000	000000	000000000	000000	000000000	000000	000000	00
3/4"-16	1 1/8"	49/64"	49/64"	MS21209F1215, NASM21209	1	000000000	00000	000000000	000000	000000000	000000	000000000	000000	000000	00
7/8"-9	7/8"	29/32"	29/32"	MS21209C1410, NASM21209	1	000000000	0000	000000000	000000	000000000	000000	000000000	00000	000000	00
7/8"-14	7/8"	57/64"	57/64"	MS21209F1410, NASM21209	1	000000000	00000	000000000	000000	000000000	000000	000000000	000000	000000	00
7/8"-14	1.312"	57/64"	57/64"	MS21209F1415, NASM21209	1	000000000	0000	000000000	000000	000000000	000000	000000000	000000	000000	00
1"-8	1"	1 1/32"	1 1/32"	MS21209C1610, NASM21209	1	000000000	00000	000000000	000000	000000000	000000	000000000	00000	000000	00
1"-8	1 1/2"	1 1/32"	1 1/32"	MS21209C1615, NASM21209	1	000000000	00000	000000000	000000	000000000	000000	000000000	00000	000000	00
1"-12	1"	1 1/32"	1 1/32"	MS21209F1610, NASM21209	1	000000000	00000	000000000	000000	000000000	000000	000000000	000000	000000	00
1"-14	1"	1 1/32"	1 1/32"	__	1	000000000	0000	000000000	000000	000000000	000000	000000000	000000	000000	00
1"-14	1 1/2"	1 1/32"	1 1/32"	__	1	000000000	00000	000000000	000000	000000000	000000	000000000	000000	000000	00
1 1/4"-7	1 7/8"	1 19/64"	1 19/64"	MS21209C2015, NASM21209	1	000000000	00000	000000000	000000	000000000	000000	000000000	000000	000000	00

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
M2.2	0.45	Coarse	3.3	2.35 mm	2.35mm	SAE MA3329-150	1	000000000	00000	000000000	000000	000000000	0000000	000000000	0000000	000000000	0000000
M2.5	0.45	Coarse	2.5	No. 37	0.104"	DIN 8140, SAE MA3329-101	10	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M2.5	0.45	Coarse	3.8	No. 37	0.104"	DIN 8140, SAE MA3329-151	10	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M2.5	0.45	Coarse	5	No. 37	0.104"	SAE MA3329-201	10	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M3	0.5	Coarse	3	3.2 mm	3.2mm	DIN 8140, SAE MA3329-102	10	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
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
M3.5	0.6	Coarse	5.3	3.7 mm	3.7mm	DIN 8140, SAE MA3329-153	1	000000000	0000	000000000	00000	000000000	000000	000000000	000000	000000000	000000
M4	0.7	Coarse	4	No. 19	0.166"	DIN 8140, SAE MA3329-104	10	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	00000
M4	0.7	Coarse	6	No. 19	0.166"	DIN 8140, SAE MA3329-154	10	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	00000
M4	0.7	Coarse	8	No. 19	0.166"	DIN 8140, SAE MA3329-204	10	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	00000
M4	0.7	Coarse	10	No. 19	0.166"	SAE MA3329-254	1	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	00000
M5	0.8	Coarse	5	5.3 mm	5.3mm	DIN 8140, SAE MA3329-105	10	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M5	0.8	Coarse	7.5	5.3 mm	5.3mm	DIN 8140, SAE MA3329-155	10	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M5	0.8	Coarse	10	5.3 mm	5.3mm	DIN 8140, SAE MA3329-205	10	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M5	0.8	Coarse	12.5	5.3 mm	5.3mm	DIN 8140, SAE MA3329-255	1	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M6	1	Coarse	6	6.3 mm	6.3mm	DIN 8140, SAE MA3329-106	10	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M6	1	Coarse	9	6.3 mm	6.3mm	DIN 8140, SAE MA3329-156	10	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M6	1	Coarse	12	6.3 mm	6.3mm	DIN 8140, SAE MA3329-206	10	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M6	1	Coarse	15	6.3 mm	6.3mm	SAE MA3329-256	1	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M7	1	Coarse	7	7.3 mm	7.3mm	SAE MA3329-107	10	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M7	1	Coarse	10.5	7.3 mm	7.3mm	SAE MA3329-157	10	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M7	1	Coarse	14	7.3 mm	7.3mm	DIN 8140, SAE MA3329-207	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M8	1.25	Coarse	8	8.4 mm	8.4mm	DIN 8140, SAE MA3329-109	10	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M8	1.25	Coarse	12	8.4 mm	8.4mm	DIN 8140, SAE MA3329-159	10	000000000	00000	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	0000	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
M10	1.5	Coarse	10	10.5 mm	10.5mm	DIN 8140, SAE MA3329-111	10	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M10	1.5	Coarse	15	10.5 mm	10.5mm	DIN 8140, SAE MA3329-161	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M10	1.5	Coarse	20	10.5 mm	10.5mm	SAE MA3329-211	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M10	1.5	Coarse	25	10.5 mm	10.5mm	DIN 8140, SAE MA3329-261	1	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M10	1.25	Fine	10	13/32"	13/32"	SAE MA3329-110	5	000000000	0000	000000000	00000	000000000	000000	000000000	000000	000000000	000000
M10	1.25	Fine	15	13/32"	13/32"	DIN 8140, SAE MA3329-160	5	000000000	0000	000000000	00000	000000000	000000	000000000	000000	000000000	000000
M10	1.25	Fine	20	13/32"	13/32"	SAE MA3329-210	5	000000000	0000	000000000	00000	000000000	000000	000000000	000000	000000000	000000
M10	1	Extra Fine	10	13/32"	13/32"	__	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M10	1	Extra Fine	15	13/32"	13/32"	DIN 8140, SAE MA3329-191	5	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M10	1	Extra Fine	20	13/32"	13/32"	__	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M12	1.75	Coarse	12	12.5 mm	12.5mm	DIN 8140, SAE MA3329-114	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M12	1.75	Coarse	18	12.5 mm	12.5mm	DIN 8140, SAE MA3329-164	5	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M12	1.75	Coarse	24	12.5 mm	12.5mm	DIN 8140, SAE MA3329-214	1	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M12	1.75	Coarse	30	12.5 mm	12.5mm	DIN 8140, SAE MA3329-264	1	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M12	1.5	Fine	18	12.5 mm	12.5mm	DIN 8140, SAE MA3329-162	1	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M12	1.25	Extra Fine	12	31/64"	31/64"	SAE MA3329-112	5	000000000	0000	000000000	00000	000000000	000000	000000000	000000	000000000	000000
M12	1.25	Extra Fine	18	31/64"	31/64"	DIN 8140, SAE MA3329-163	1	000000000	0000	000000000	00000	000000000	000000	000000000	000000	000000000	000000
M12	1.25	Extra Fine	24	31/64"	31/64"	SAE MA3329-212	1	000000000	0000	000000000	00000	000000000	000000	000000000	000000	000000000	000000
M14	2	Coarse	14	14.5 mm	14.5mm	SAE MA3329-116	1	000000000	0000	000000000	000000	000000000	000000	000000000	000000	000000	00
M14	2	Coarse	21	14.5 mm	14.5mm	DIN 8140, SAE MA3329-166	1	000000000	0000	000000000	000000	000000000	000000	000000000	000000	000000	00
M14	1.5	Fine	21	37/64"	37/64"	DIN 8140, SAE MA3329-165	1	000000000	0000	000000000	00000	000000000	000000	000000000	000000	000000	00
M16	2	Coarse	16	16.5 mm	16.5mm	DIN 8140, SAE MA3329-118	1	000000000	00000	000000000	000000	000000000	000000	000000000	000000	000000	00
M16	2	Coarse	24	16.5 mm	16.5mm	DIN 8140, SAE MA3329-168	1	000000000	0000	000000000	000000	000000000	000000	000000000	000000	000000	00
M18	2.5	Coarse	18	47/64"	47/64"	SAE MA3329-121	1	000000000	0000	000000000	000000	000000000	000000	000000000	000000	000000	00
M18	2.5	Coarse	27	47/64"	47/64"	SAE MA3329-171	1	000000000	0000	000000000	000000	000000000	000000	000000000	000000	000000	00
M20	2.5	Coarse	20	13/16"	13/16"	SAE MA3329-124	1	000000000	0000	000000000	000000	000000000	000000	000000000	000000	000000	00
M20	2.5	Coarse	30	13/16"	13/16"	SAE MA3329-174	1	000000000	0000	000000000	000000	000000000	000000	000000000	000000	000000	00
M24	3	Coarse	36	31/32"	31/32"	DIN 8140, SAE MA3329-179	1	000000000	0000	000000000	000000	000000000	000000	000000000	00000	000000	00
M30	3.5	Coarse	45	1 7/32"	1 7/32"	DIN 8140	1	000000000	00000	000000000	000000	000000000	000000	000000000	00000	000000	00

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.

Inch

Inserts								Through-Hole Taps		Closed-End Hole Taps		Installation Tools		Prong Break-Off Tools
Thread Size	Installed Lg.	Drill Bit Size	For Max. Hole Dia.	Specifications Met	Pkg. Qty.		Pkg.		Each		Each		Each		Each
18-8 Stainless Steel
2-56	0.086"	No. 41	0.096"	MS21209C0210L, NASM21209	5	000000000	00000	000000000	000000	000000000	000000	000000000	000000	000000000	0000000
2-56	0.129"	No. 41	0.096"	MS21209C0215L, NASM21209	5	000000000	0000	000000000	00000	000000000	00000	000000000	00000	000000000	000000
2-56	0.172"	No. 41	0.096"	MS21209C0220L, NASM21209	5	000000000	0000	000000000	00000	000000000	00000	000000000	00000	000000000	000000
4-40	0.112"	No. 31	0.12"	MS21209C0410L, NASM21209	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
4-40	0.168"	No. 31	0.12"	MS21209C0415L, NASM21209	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
4-40	0.224"	No. 31	0.12"	MS21209C0420L, NASM21209	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
6-32	0.138"	No. 25	0.1495"	MS21209C0610L, NASM21209	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	00000
6-32	0.207"	No. 25	0.1495"	MS21209C0615L, NASM21209	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	00000
6-32	0.276"	No. 25	0.1495"	MS21209C0620L, NASM21209	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	00000
10-24	0.285"	No. 5	0.2055"	MS21209C1-15L, NASM21209	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
10-32	0.19"	13/64"	13/64"	MS21209F1-10L, NASM21209	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
10-32	0.285"	13/64"	13/64"	MS21209F1-15L, NASM21209	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
10-32	0.38"	13/64"	13/64"	MS21209F1-20L, NASM21209	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
1/4"-20	3/8"	H	0.266"	MS21209C4-15L, NASM21209	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
1/4"-20	1/2"	H	0.266"	MS21209C4-20L, NASM21209	1	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
5/16"-18	0.469"	Q	0.332"	MS21209C5-15L, NASM21209	1	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
5/16"-18	5/8"	Q	0.332"	MS21209C5-20L, NASM21209	1	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000

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
M2.5	0.45	3.8	No. 37	0.104"	DIN 8140, SAE MA3330-151	1	000000000	00000	000000000	000000	000000000	000000	000000000	0000000	000000000	0000000
M4	0.7	4	No. 19	0.166"	DIN 8140, SAE MA3330-104	1	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	00000
M4	0.7	6	No. 19	0.166"	DIN 8140, SAE MA3330-154	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	00000
M4	0.7	8	No. 19	0.166"	DIN 8140, SAE MA3330-204	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	00000
M5	0.8	5	5.3 mm	5.3mm	SAE MA3330-105	1	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M5	0.8	7.5	5.3 mm	5.3mm	DIN 8140, SAE MA3330-155	1	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M5	0.8	10	5.3 mm	5.3mm	DIN 8140, SAE MA3330-205	1	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M6	1	6	6.3 mm	6.3mm	SAE MA3330-106	1	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M6	1	9	6.3 mm	6.3mm	DIN 8140, SAE MA3330-156	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M6	1	12	6.3 mm	6.3mm	DIN 8140, SAE MA3330-206	1	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
M8	1.25	8	8.4 mm	8.4mm	DIN 8140, SAE MA3330-109	1	000000000	0000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
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

Stainless Steel Screw-Locking 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. Once the screw is installed, 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.

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

Inserts							Through-Hole Taps		Closed-End 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		Each
Nitronic 60 Stainless Steel
2-56	0.086"	No. 41	0.096"	5	000000000	000000	000000000	000000	000000000	000000	000000000	000000	000000000	0000000
2-56	0.129"	No. 41	0.096"	5	000000000	00000	000000000	00000	000000000	00000	000000000	00000	000000000	000000
4-40	0.112"	No. 31	0.12"	5	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
4-40	0.168"	No. 31	0.12"	5	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
4-40	0.224"	No. 31	0.12"	5	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
6-32	0.138"	No. 25	0.1495"	5	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	00000
6-32	0.207"	No. 25	0.1495"	5	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	00000
8-32	0.164"	No. 16	0.177"	5	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	00000
8-32	0.246"	No. 16	0.177"	5	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	00000
8-32	0.328"	No. 16	0.177"	5	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	00000
10-24	0.19"	No. 5	0.2055"	5	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
10-24	0.285"	No. 5	0.2055"	5	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
10-32	0.19"	13/64"	13/64"	5	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
10-32	0.285"	13/64"	13/64"	5	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
1/4"-20	1/4"	H	0.266"	5	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
1/4"-20	3/8"	H	0.266"	5	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
1/4"-20	1/2"	H	0.266"	5	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
5/16"-18	0.312"	Q	0.332"	5	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
5/16"-18	0.469"	Q	0.332"	5	000000000	00000	000000000	00000	000000000	00000	000000000	000000	000000000	000000
5/16"-18	5/8"	Q	0.332"	5	000000000	00000	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.

Inch

Inserts								Through-Hole Taps		Closed-End Hole Taps		Installation Tools
Thread Size	Installed Lg.	Drill Bit Size	For Max. Hole Dia.	Specifications Met	Pkg. Qty.		Pkg.		Each		Each		Each
18-8 Stainless Steel
2-56	0.086"	No. 41	0.096"	NAS1130-02L-10	5	000000000	00000	000000000	000000	000000000	000000	000000000	0000000
2-56	0.129"	No. 41	0.096"	NAS1130-02L-15	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000
2-56	0.172"	No. 41	0.096"	NAS1130-02L-20	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000
4-40	0.112"	No. 31	0.12"	NAS1130-04L-10	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000
4-40	0.168"	No. 31	0.12"	NAS1130-04L-15	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000
4-40	0.224"	No. 31	0.12"	NAS1130-04L-20	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000
6-32	0.138"	No. 25	0.1495"	NAS1130-06L-10	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000
6-32	0.207"	No. 25	0.1495"	NAS1130-06L-15	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000
6-32	0.276"	No. 25	0.1495"	NAS1130-06L-20	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000
8-32	0.164"	No. 16	0.177"	NAS1130-08L-10	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000
8-32	0.246"	No. 16	0.177"	NAS1130-08L-15	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000
8-32	0.328"	No. 16	0.177"	NAS1130-08L-20	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000
10-24	0.19"	No. 5	0.2055"	NAS1130-3CL-10	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000
10-24	0.38"	No. 5	0.2055"	NAS1130-3CL-20	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000
10-32	0.19"	13/64"	13/64"	NAS1130-3L-10	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000
10-32	0.285"	13/64"	13/64"	NAS1130-3L-15	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000
10-32	0.38"	13/64"	13/64"	NAS1130-3L-20	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000
1/4"-20	1/4"	H	0.266"	NAS1130-4L-10	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000
1/4"-20	3/8"	H	0.266"	NAS1130-4L-15	5	000000000	0000	000000000	00000	000000000	00000	000000000	000000

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
M2.5	0.45	2.5	No. 37	0.104"	NA0276M2A-L10	10	000000000	00000	000000000	000000	000000000	000000	000000000	0000000
M3	0.5	3	3.2 mm	3.2mm	NA0276M3-L10	10	000000000	0000	000000000	00000	000000000	00000	000000000	000000
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
M4	0.7	4	No. 19	0.166"	NA0276M4-L10	10	000000000	0000	000000000	00000	000000000	00000	000000000	000000
M4	0.7	6	No. 19	0.166"	NA0276M4-L15	10	000000000	0000	000000000	00000	000000000	00000	000000000	000000
M4	0.7	8	No. 19	0.166"	NA0276M4-L20	10	000000000	0000	000000000	00000	000000000	00000	000000000	000000
M5	0.8	5	5.3 mm	5.3mm	NA0276M5-L10	10	000000000	0000	000000000	00000	000000000	00000	000000000	000000
M5	0.8	10	5.3 mm	5.3mm	NA0276M5-L20	10	000000000	00000	000000000	00000	000000000	00000	000000000	000000
M6	1	6	6.3 mm	6.3mm	NA0276M6-L10	10	000000000	0000	000000000	00000	000000000	00000	000000000	000000
M6	1	9	6.3 mm	6.3mm	NA0276M6-L15	10	000000000	0000	000000000	00000	000000000	00000	000000000	000000
M6	1	12	6.3 mm	6.3mm	NA0276M6-L20	10	000000000	0000	000000000	00000	000000000	00000	000000000	000000