Perma-Kee®

KATO Perma-Kee inserts are solid, one piece, kee-locking inserts used to repair stripped or damaged threads in all types of metals and applications. When installed, locking-kees are driven into the surrounding parent material, locking the insert into place and keeping it from rotating due to vibration or torsion. No special taps are needed.

Perma-Kee inserts are available in carbon or stainless steel, both inch and metric series, and a variety of wall thickness – thinwall, heavy duty, extra heavy duty and solid styles.

Perma-Kee inserts are sold in bulk quantities. Installation tools sold separately.

Thinwall Inserts

Thread Size External Thread Size
(Tap Size)		 TK Part No. Drill Size Tool
Carbon Steel Stainless Steel1
Unified Sizes
10-24 5/16-18 PKTC-3 PKTC-3S I PKT-3T
10-32 5/16-18 PKTF-3 PKTF-3S I PKT-3T
1/4-20 3/8-16 PKTC-4 PKTC-4S Q PKT-4T
1/4-28 3/8-16 PKTF-4 PKTF-4S Q PKT-4T
5/16-18 7/16-14 PKTC-5 PKTC-5S X PKT-5T
5/16-24 7/16-14 PKTF-5 PKTF-5S X PKT-5T
3/8-16 1/2-13 PKTC-6 PKTC-6S 29/64 PKT-6T
3/8-24 1/2-13 PKTF-6 PKTF-6S 29/64 PKT-6T
7/16-14 9/16-12 PKTC-7 PKTC-7S 33/64 PKT-7T
7/16-20 9/16-12 PKTF-7 PKTF-7S 33/64 PKT-7T
1/2-13 5/8-11 PKTC-8 PKTC-8S 37/64 PKT-8T
1/2-20 5/8-11 PKTF-8 PKTF-8S 37/64 PKT-8T
Metric Sizes
M5x.8 M8X1.25 PKTM-5X.8 PKTM-5X.8S 6.9 PKTM-5T
M6x1 M10X1.25 PKTM-6X1 PKTM-6X1S 8.8 PKTM-6T
M8x1 M12X1.25 PKTM-8X1 PKTM-8X1S 10.8 PKTM-8T
M8x1.25 M12X1.25 PKTM-8X1.25 PKTM-8X1.25S 10.8 PKTM-8T
M10x1.25 M14X1.5 PKTM-10X1.25 PKTM-10X1.25S 12.8 PKTM-10T
M10x1.5 M14X1.5 PKTM-10X1.5 PKTM-10X1.5S 12.8 PKTM-10T
M12x1.25 M16X1.5 PKTM-12X1.25 PKTM-12X1.25S 14.75 PKTM-12T
M12x1.75 M16X1.5 PKTM-12X1.75 PKTM-12X1.75S 14.75 PKTM-12T
  1. Stainless Steel Perma-Kee may have longer lead times.

Thinwall Kits

Perma-Kee Kit Includes:

  • HSS Drill
  • HSS Tap
  • Installation Tool
  • Perma-Kee inserts (See Table)
Internal
Thread		 External
Thread		 Kits Part No. Inserts
per Kit
Unified Sizes
10-24 5/16-18 PKTC-3K 4
10-32 5/16-18 PKTF-3K 4
1/4-20 3/8-16 PKTC-4K 4
1/4-28 3/8-16 PKTF-4K 4
5/16-18 7/16-14 PKTC-5K 4
5/16-24 7/16-14 PKTF-5K 4
3/8-16 1/2-13 PKTC-6K 3
3/8-24 1/2-13 PKTF-6K 3
7/16-14 9/16-12 PKTC-7K 3
7/16-20 9/16-12 PKTF-7K 3
1/2-13 5/8-11 PKTC-8K 3
1/2-20 5/8-11 PKTF-8K 3
Metric Sizes
M5x.8 M8X1.25 PKTM-5X.8K 4
M6x1 M10X1.25 PKTM-6X1K 4
M8x1 M12X1.25 PKTM-8X1K 4
M8x1.25 M12X1.25 PKTM-8X1.25K 4
M10x1.25 M14X1.5 PKTM-10X1.25K 3
M10x1.5 M14X1.5 PKTM-10X1.5K 3
M12x1.25 M16X1.5 PKTM-12X1.25K 3
M12x1.75 M16X1.5 PKTM-12X1.75K 3

Heavy Duty Inserts

Thread Size External Thread Size
(Tap Size)		 TK Part No. Drill Size Tool
Carbon Steel Stainless Steel1
Unified Sizes
8-32 5/16-18 PKHC-2 PKHC-2S I PKH-2T
10-24 3/8-16 PKHC-3 PKHC-3S Q PKH-3T
10-32 3/8-16 PKHF-3 PKHF-3S Q PKH-3T
1/4-20 7/16-14 PKHC-4 PKHC-4S X PKH-4T
1/4-28 7/16-14 PKHF-4 PKHF-4S X PKH-4T
5/16-18 1/2-13 PKHC-5 PKHC-5S 29/64 PKH-5T
5/16-24 1/2-13 PKHF-5 PKHF-5S 29/64 PKH-5T
3/8-16 9/16-12 PKHC-6 PKHC-6S 33/64 PKH-6T
3/8-24 9/16-12 PKHF-6 PKHF-6S 33/64 PKH-6T
7/16-14 5/8-11 PKHC-7 PKHC-7S 37/64 PKH-7T
7/16-20 5/8-11 PKHF-7 PKHF-7S 37/64 PKH-7T
1/2-13 3/4-16 PKHC-8 PKHC-8S 45/64 PKH-8T
1/2-20 3/4-16 PKHF-8 PKHF-8S 45/64 PKH-8T
9/16-12 3/4-16 PKHC-9 PKHC-9S 45/64 PKH-9T
9/16-18 3/4-16 PKHF-9 PKHF-9S 45/64 PKH-9T
5/8-11 7/8-14 PKHC-10 PKHC-10S 53/64 PKH-10T
5/8-18 7/8-14 PKHF-10 PKHF-10S 53/64 PKH-10T
3/4-10 1 1/8-12 PKHC-12 PKHC-12S 1 1/16 PKH-12T
3/4-16 1 1/8-12 PKHF-12 PKHF-12S 1 1/16 PKH-12T
7/8-9 1 1/4-12 PKHC-14 PKHC-14S 1 3/16 PKH-14T
7/8-14 1 1/4-12 PKHF-14 PKHF-14S 1 3/16 PKH-14T
1-8 1 3/8-12 PKHC-16 PKHC-16S 1 5/16 PKH-16T
1-12 1 3/8-12 PKHF-16 PKHF-16S 1 5/16 PKH-16T
Metric Sizes
M4X0.7 M8X1.25 PKHM-4X.7 PKHM-4X.7S 6.90 PKHM-4T
M5X0.8 M10X1.25 PKHM-5X.8 PKHM-5X.8S 8.80 PKHM-5T
M6X1 M12X1.25 PKHM-6X1 PKHM-6X1S 10.80 PKHM-6T
M8X1 M14X1.5 PKHM-8X1 PKHM-8X1S 12.80 PKHM-8T
M8X1.25 M14X1.5 PKHM-8X1.25 PKHM-8X1.25S 12.80 PKHM-8T
M10X1.25 M16X1.5 PKHM-10X1.25 PKHM-10X1.25S 14.75 PKHM-10T
M10X1.5 M16X1.5 PKHM-10X1.5 PKHM-10X1.5S 14.75 PKHM-10T
M12X1.25 M18X1.5 PKHM-12X1.25 PKHM-12X1.25S 16.75 PKHM-12T
M12X1.75 M18X1.5 PKHM-12X1.75 PKHM-12X1.75S 16.75 PKHM-12T
M14X1.5 M20X1.5 PKHM-14X1.5 PKHM-14X1.5S 18.75 PKHM-14T
M14X2 M20X1.5 PKHM-14X2 PKHM-14X2S 18.75 PKHM-14T
M16X1.5 M22X1.5 PKHM-16X1.5 PKHM-16X1.5S 20.50 PKHM-16T
M16X2 M22X1.5 PKHM-16X2 PKHM-16X2S 20.50 PKHM-16T
M18X1.5 M24X1.5 PKHM-18X1.5 PKHM-18X1.5S 22.50 PKHM-18T
M20X1.5 M30X2 PKHM-20X1.5 PKHM-20X1.5S 28.00 PKHM-20T
M20X2.5 M30X2 PKHM-20X2.5 PKHM-20X2.5S 28.00 PKHM-20T
M22X1.5 M32X2 PKHM-22X1.5 PKHM-22X1.5S 30.00 PKHM-22T
M24X2 M33X2 PKHM-24X2 PKHM-24X2S 31.00 PKHM-24T
M24X3 M33X2 PKHM-24X3 PKHM-24X3S 31.00 PKHM-24T
  1. Stainless Steel Perma-Kee may have longer lead times.

Heavy Duty Kits

Perma-Kee Kit Includes:

  • HSS Drill
  • HSS Tap
  • Installation Tool
  • Perma-Kee inserts (See Table)
Internal
Thread 		External
Thread 		Kits
Part No.		 Inserts
per Kits
Unified Sizes
10-24 3/8-16 PKHC-3K 4
10-32 3/8-16 PKHF-3K 4
1/4-20 7/16-14 PKHC-4K 4
1/4-28 7/16-14 PKHF-4K 4
5/16-18 1/2-13 PKHC-5K 4
5/16-24 1/2-13 PKHF-5K 4
3/8-16 9/16-12 PKHC-6K 3
3/8-24 9/16-12 PKHF-6K 3
7/16-14 5/8-11 PKHC-7K 3
7/16-20 5/8-11 PKHF-7K 3
1/2-13 3/4-16 PKHC-8K 3
1/2-20 3/4-16 PKHF-8K 3
9/16-12 3/4-16 PKHC-9K 3
9/16-18 3/4-16 PKHF-9K 3
5/8-11 7/8-14 PKHC-10K 2
5/8-18 7/8-14 PKHF-10K 2
Metric Sizes
M5X0.8 M10X1.25 PKHM-5X.8K 4
M6X1 M12X1.25 PKHM-6X1K 4
M8X1 M14X1.5 PKHM-8X1K 4
M8X1.25 M14X1.5 PKHM-8X1.25K 4
M10X1.25 M16X1.5 PKHM-10X1.25K 3
M10X1.5 M16X1.5 PKHM-10X1.5K 3
M12X1.25 M18X1.5 PKHM-12X1.25K 3
M12X1.75 M18X1.5 PKHM-12X1.75K 3

Frequently Asked Questions (FAQs)

What comes inside a Perma-Kee kit?

Perma-Kee Key Locking Inserts are solid steel inserts designed to permanently repair damaged or stripped threads. The built-in locking keys secure the insert into the parent material, creating strong, durable threads that resist loosening and wear.

When should I use a key locking insert instead of a wire thread insert?

Key locking inserts are ideal for repairs that require greater strength and resistance to vibration. They provide a more permanent solution than wire thread inserts and are commonly used in heavy-duty, industrial, and automotive applications.

What comes in a Perma-Kee Thread Repair Kit?

Each Perma-Kee® Thread Repair Kit includes the tools needed to complete a thread repair, including the correct drill bit, STI tap, installation tool, and key locking inserts. Everything is packaged together for a fast and convenient repair.

What materials can Perma-Kee inserts be installed in?

Perma-Kee® inserts can be installed in aluminum, steel, cast iron, magnesium, and many other metals. They restore damaged threads with a strong, long-lasting repair suitable for a variety of applications.

What is your cancellation/refund policy?

Customers may request a cancellation and full refund provided the purchased tool has not been opened, accessed, activated, or used. Refund requests must be submitted before any use of the tool.

We reserve the right to verify whether a tool has been opened, accessed, activated, or used before approving any refund request.

What are your hours of operation?

Our standard hours of operation are Monday to Friday, 8:30 AM to 4:30 PM in Pacific Standard Time (PST).

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