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.

Inch
Includes	No. of Inserts Included	Thread Spacing	Drill Bit Size	For Max. Hole Dia.		Each
18-8 Stainless Steel
1-64 Thread × 0.11" Installed Lg. (24 Inserts and 24 Screw-Locking Inserts) 2-56 Thread × 0.129" Installed Lg. (24 Inserts and 24 Screw-Locking Inserts) 3-48 Thread × 0.148" Installed Lg. (24 Inserts and 24 Screw-Locking Inserts) 4-40 Thread × 0.168" Installed Lg. (24 Inserts and 24 Screw-Locking Inserts) 6-32 Thread × 0.207" Installed Lg. (24 Inserts and 24 Screw-Locking Inserts) 8-32 Thread × 0.246" Installed Lg. (24 Inserts and 24 Screw-Locking Inserts) Drill Bits Through-Hole Taps Installation Tools	288	Coarse	5/64" 3/32" No. 36 No. 31 No. 26 No. 17	5/64" 3/32" 0.1065" 0.12" 0.147" 0.173"	000000000	0000000
4-40 Thread × 0.112" Installed Lg. (12 Each) 4-40 Thread × 0.168" Installed Lg. (12 Each) 4-40 Thread × 0.224" Installed Lg. (12 Each) Drill Bit Through-Hole Tap Installation Tool	36	Coarse	No. 31	0.12"	000000000	00000
5-40 Thread × 1/8" Installed Lg. (12 Each) 5-40 Thread × 0.188" Installed Lg. (12 Each) 5-40 Thread × 1/4" Installed Lg. (12 Each) Drill Bit Through-Hole Tap Installation Tool	36	Coarse	No. 29	0.136"	000000000	000000
6-32 Thread × 0.138" Installed Lg. (12 Each) 6-32 Thread × 0.207" Installed Lg. (12 Each) 6-32 Thread × 0.276" Installed Lg. (12 Each) Drill Bit Through-Hole Tap Installation Tool	36	Coarse	No. 25	0.1495"	000000000	00000
6-40 Thread × 0.138" Installed Lg. (12 Each) 6-40 Thread × 0.207" Installed Lg. (12 Each) 6-40 Thread × 0.276" Installed Lg. (12 Each) Drill Bit Through-Hole Tap Installation Tool	36	Fine	No. 25	0.1495"	000000000	000000
8-32 Thread × 0.164" Installed Lg. (12 Each) 8-32 Thread × 0.246" Installed Lg. (12 Each) 8-32 Thread × 0.328" Installed Lg. (12 Each) Drill Bit Through-Hole Tap Installation Tool	36	Coarse	11/64"	11/64"	000000000	00000
8-36 Thread × 0.164" Installed Lg. (12 Each) 8-36 Thread × 0.246" Installed Lg. (12 Each) 8-36 Thread × 0.328" Installed Lg. (12 Each) Drill Bit Through-Hole Tap Installation Tool	36	Fine	No. 17	0.173"	000000000	000000
10-24 Thread × 0.19" Installed Lg. (12 Each) 10-24 Thread × 0.285" Installed Lg. (12 Each) 10-24 Thread × 0.38" Installed Lg. (12 Each) Drill Bit Through-Hole Tap Installation Tool	36	Coarse	13/64"	13/64"	000000000	00000
10-32 Thread × 0.19" Installed Lg. (12 Each) 10-32 Thread × 0.285" Installed Lg. (12 Each) 10-32 Thread × 0.38" Installed Lg. (12 Each) Drill Bit Through-Hole Tap Installation Tool	36	Fine	13/64"	13/64"	000000000	00000
10-32 Thread × 0.285" Installed Lg. (12 Each) 1/4"-28 Thread × 3/8" Installed Lg. (12 Each) 5/16"-24 Thread × 0.469" Installed Lg. (12 Each) 3/8"-24 Thread × 0.562" Installed Lg. (12 Each) 7/16"-20 Thread × 0.656" Installed Lg. (6 Each) 1/2"-20 Thread × 3/4" Installed Lg. (6 Each) Drill Bits Through-Hole Taps Installation Tools	60	Fine	13/64" 17/64" 21/64" 25/64" 29/64" 33/64"	13/64" 17/64" 21/64" 25/64" 29/64" 33/64"	000000000	000000
12-24 Thread × 0.216" Installed Lg. (12 Each) 12-24 Thread × 0.328" Installed Lg. (12 Each) 12-24 Thread × 0.432" Installed Lg. (12 Each) Drill Bit Through-Hole Tap Installation Tool	36	Coarse	15/64"	15/64"	000000000	00000
1/4"-20 Thread × 1/4" Installed Lg. (12 Each) 1/4"-20 Thread × 3/8" Installed Lg. (12 Each) 1/4"-20 Thread × 1/2" Installed Lg. (12 Each) Drill Bit Through-Hole Tap Installation Tool	36	Coarse	17/64"	17/64"	000000000	00000
1/4"-20 Thread × 3/8" Installed Lg. (12 Each) 5/16"-18 Thread × 0.469" Installed Lg. (12 Each) 3/8"-16 Thread × 0.562" Installed Lg. (12 Each) 7/16"-14 Thread × 0.656" Installed Lg. (6 Each) 1/2"-13 Thread × 3/4" Installed Lg. (6 Each) 5/8"-11 Thread × 15/16" Installed Lg. (6 Each) Drill Bits Through-Hole Taps Installation Tools	54	Coarse	17/64" 21/64" 25/64" 29/64" 17/32" 21/32"	17/64" 21/64" 25/64" 29/64" 17/32" 21/32"	000000000	000000
1/4"-28 Thread × 1/4" Installed Lg. (12 Each) 1/4"-28 Thread × 3/8" Installed Lg. (12 Each) 1/4"-28 Thread × 1/2" Installed Lg. (12 Each) Drill Bit Through-Hole Tap Installation Tool	36	Fine	17/64"	17/64"	000000000	00000
5/16"-18 Thread × 0.312" Installed Lg. (12 Each) 5/16"-18 Thread × 0.469" Installed Lg. (12 Each) 5/16"-18 Thread × 5/8" Installed Lg. (12 Each) Drill Bit Through-Hole Tap Installation Tool	36	Coarse	21/64"	21/64"	000000000	00000
5/16"-24 Thread × 0.312" Installed Lg. (12 Each) 5/16"-24 Thread × 0.469" Installed Lg. (12 Each) 5/16"-24 Thread × 5/8" Installed Lg. (12 Each) Drill Bit Through-Hole Tap Installation Tool	36	Fine	21/64"	21/64"	000000000	00000
3/8"-16 Thread × 3/8" Installed Lg. (6 Each) 3/8"-16 Thread × 0.562" Installed Lg. (6 Each) 3/8"-16 Thread × 3/4" Installed Lg. (6 Each) Drill Bit Through-Hole Tap Installation Tool	18	Coarse	25/64"	25/64"	000000000	00000
3/8"-24 Thread × 3/8" Installed Lg. (6 Each) 3/8"-24 Thread × 0.562" Installed Lg. (6 Each) 3/8"-24 Thread × 3/4" Installed Lg. (6 Each) Drill Bit Through-Hole Tap Installation Tool	18	Fine	25/64"	25/64"	000000000	00000
7/16"-14 Thread × 0.438" Installed Lg. (6 Each) 7/16"-14 Thread × 0.656" Installed Lg. (6 Each) 7/16"-14 Thread × 7/8" Installed Lg. (6 Each) Drill Bit Through-Hole Tap Installation Tool	18	Coarse	29/64"	29/64"	000000000	00000
7/16"-20 Thread × 0.438" Installed Lg. (6 Each) 7/16"-20 Thread × 0.656" Installed Lg. (6 Each) 7/16"-20 Thread × 7/8" Installed Lg. (6 Each) Drill Bit Through-Hole Tap Installation Tool	18	Fine	29/64"	29/64"	000000000	00000
1/2"-13 Thread × 1/2" Installed Lg. (6 Each) 1/2"-13 Thread × 3/4" Installed Lg. (6 Each) 1/2"-13 Thread × 1" Installed Lg. (6 Each) Drill Bit Through-Hole Tap Installation Tool	18	Coarse	17/32"	17/32"	000000000	00000
1/2"-20 Thread × 1/2" Installed Lg. (6 Each) 1/2"-20 Thread × 3/4" Installed Lg. (6 Each) 1/2"-20 Thread × 1" Installed Lg. (6 Each) Drill Bit Through-Hole Tap Installation Tool	18	Fine	33/64"	33/64"	000000000	000000
Metric
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	000000
M4×0.7 mm Thread × 4 mm Installed Lg. (6 Each) M4×0.7 mm Thread × 6 mm Installed Lg. (6 Each) M4×0.7 mm Thread × 8 mm Installed Lg. (6 Each) Drill Bit Through-Hole Tap Installation Tool	18	Coarse	11/64"	11/64"	000000000	00000
M5×0.8 mm Thread × 5 mm Installed Lg. (6 Each) M5×0.8 mm Thread × 7.5 mm Installed Lg. (6 Each) M5×0.8 mm Thread × 10 mm Installed Lg. (6 Each) Drill Bit Through-Hole Tap Installation Tool	18	Coarse	13/64"	13/64"	000000000	00000
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	000000
M6×1 mm Thread × 6 mm Installed Lg. (6 Each) M6×1 mm Thread × 9 mm Installed Lg. (6 Each) M6×1 mm Thread × 12 mm Installed Lg. (6 Each) Drill Bit Through-Hole Tap Installation Tool	18	Coarse	1/4"	1/4"	000000000	00000
M7×1 mm Thread × 7 mm Installed Lg. (6 Each) M7×1 mm Thread × 10.5 mm Installed Lg. (6 Each) M7×1 mm Thread × 14 mm Installed Lg. (6 Each) Drill Bit Through-Hole Tap Installation Tool	18	Coarse	9/32"	9/32"	000000000	00000
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
M10×1 mm Thread × 10 mm Installed Lg. (6 Each) M10×1 mm Thread × 15 mm Installed Lg. (6 Each) M10×1 mm Thread × 20 mm Installed Lg. (6 Each) Drill Bit Through-Hole Tap Installation Tool	18	Fine	13/32"	13/32"	000000000	000000
M10×1.5 mm Thread × 10 mm Installed Lg. (6 Each) M10×1.5 mm Thread × 15 mm Installed Lg. (6 Each) M10×1.5 mm Thread × 20 mm Installed Lg. (6 Each) Drill Bit Through-Hole Tap Installation Tool	18	Coarse	13/32"	13/32"	000000000	00000
M12×1.25 mm Thread × 12 mm Installed Lg. (6 Each) M12×1.25 mm Thread × 18 mm Installed Lg. (6 Each) M12×1.25 mm Thread × 24 mm Installed Lg. (6 Each) Drill Bit Through-Hole Tap Installation Tool	18	Extra Fine	31/64"	31/64"	000000000	000000
M12×1.75 mm Thread × 12 mm Installed Lg. (6 Each) M12×1.75 mm Thread × 18 mm Installed Lg. (6 Each) M12×1.75 mm Thread × 24 mm Installed Lg. (6 Each) Drill Bit Through-Hole Tap Installation Tool	18	Coarse	31/64"	31/64"	000000000	00000

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.

Inch

18-8 Stainless Steel—Right-Hand Threaded
Thread Size	Installed Lg.	Drill Bit Size	For Max. Hole Dia.	No. of Inserts Included	Includes		Each
4-40	0.224"	No. 31	0.12"	10	Drill Bit, Through-Hole Tap, Installation Tool	000000000	000000
6-32	0.138"	No. 25	0.1495"	10	Drill Bit, Through-Hole Tap, Installation Tool	000000000	00000
6-32	0.276"	No. 25	0.1495"	10	Drill Bit, Through-Hole Tap, Installation Tool	000000000	00000
8-32	0.164"	11/64"	11/64"	10	Drill Bit, Through-Hole Tap, Installation Tool	000000000	00000
8-32	0.328"	11/64"	11/64"	10	Drill Bit, Through-Hole Tap, Installation Tool	000000000	00000
10-24	0.38"	13/64"	13/64"	10	Drill Bit, Through-Hole Tap, Installation Tool	000000000	00000
10-32	0.19"	13/64"	13/64"	10	Drill Bit, Through-Hole Tap, Installation Tool	000000000	00000
10-32	0.38"	13/64"	13/64"	10	Drill Bit, Through-Hole Tap, Installation Tool	000000000	00000
1/4"-20	1/4"	17/64"	17/64"	10	Drill Bit, Through-Hole Tap, Installation Tool	000000000	00000
1/4"-20	1/2"	17/64"	17/64"	10	Drill Bit, Through-Hole Tap, Installation Tool	000000000	00000
5/16"-18	0.312"	21/64"	21/64"	10	Drill Bit, Through-Hole Tap, Installation Tool	000000000	00000
5/16"-18	5/8"	21/64"	21/64"	10	Drill Bit, Through-Hole Tap, Installation Tool	000000000	00000
3/8"-16	3/8"	25/64"	25/64"	10	Drill Bit, Through-Hole Tap, Installation Tool	000000000	00000
3/8"-16	3/4"	25/64"	25/64"	5	Drill Bit, Through-Hole Tap, Installation Tool	000000000	00000
1/2"-13	1/2"	17/32"	17/32"	10	Drill Bit, Through-Hole Tap, Installation Tool	000000000	00000
1/2"-13	1"	17/32"	17/32"	5	Drill Bit, Through-Hole Tap, Installation Tool	000000000	00000

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	1/8"	1/8"	10	Drill Bit, Through-Hole Tap, Installation Tool	000000000	0000000
M3	0.5	Coarse	6	1/8"	1/8"	10	Drill Bit, Through-Hole Tap, Installation Tool	000000000	000000
M4	0.7	Coarse	4	11/64"	11/64"	10	Drill Bit, Through-Hole Tap, Installation Tool	000000000	00000
M4	0.7	Coarse	8	11/64"	11/64"	10	Drill Bit, Through-Hole Tap, Installation Tool	000000000	00000
M5	0.8	Coarse	5	13/64"	13/64"	10	Drill Bit, Through-Hole Tap, Installation Tool	000000000	00000
M5	0.8	Coarse	10	13/64"	13/64"	10	Drill Bit, Through-Hole Tap, Installation Tool	000000000	00000
M6	1	Coarse	6	1/4"	1/4"	10	Drill Bit, Through-Hole Tap, Installation Tool	000000000	00000
M6	1	Coarse	12	1/4"	1/4"	10	Drill Bit, Through-Hole Tap, Installation Tool	000000000	00000
M8	1.25	Coarse	8	21/64"	21/64"	10	Drill Bit, Through-Hole Tap, Installation Tool	000000000	000000
M8	1.25	Coarse	16	21/64"	21/64"	10	Drill Bit, Through-Hole Tap, Installation Tool	000000000	000000

Spark Plug Thread Repair Kits for Gasket-Seat and Taper-Seat Ports

These kits have short-, normal-, and long-reach inserts, an installation tool, and a tap.

18-8 Stainless Steel
Includes	No. of Inserts Included		Each
M14×1.25 mm Thread × Short Insert Reach (1 Each) M14×1.25 mm Thread × Normal Insert Reach (1 Each) M14×1.25 mm Thread × Long Insert Reach (1 Each) Through-Hole Tap Installation Tool	3	000000000	000000
M14×1.25 mm Thread × Short Insert Reach (6 Each) M14×1.25 mm Thread × Normal Insert Reach (6 Each) M14×1.25 mm Thread × Long Insert Reach (6 Each) Through-Hole Tap Installation Tool	18	000000000	000000

Spark Plug Thread Repair Kits

Kits include helical inserts, a tap, and an 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.

18-8 Stainless Steel
Includes	No. of Inserts Included		Each
M14×1.25 mm Thread × 3/8" Insert Reach (6 Each) M14×1.25 mm Thread × 7/16" Insert Reach (6 Each) M14×1.25 mm Thread × 0.472" Insert Reach (6 Each) M14×1.25 mm Thread × 1/2" Insert Reach (6 Each) M14×1.25 mm Thread × 3/4" Insert Reach (6 Each) Through-Hole Tap Installation Tool	30	000000000	0000000
M18×1.5 mm Thread × 1/2" Insert Reach (24 Each) Through-Hole Tap Installation Tool	24	000000000	000000