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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 |
- 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 |
- 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 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 | |
Frequently Asked Questions (FAQs)
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.
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.
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.
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.
Our cancellation policy allows you to cancel your subscription at any time through your account settings. Regarding refunds, our policy is we offer a 30-day money-back guarantee. Please refer to our Terms of Service Page for complete details.
Our standard hours of operation are Monday to Friday, 9:00 AM to 5:00 PM in Pacific Standard Time (PST).