Standards for Tangless and Tang-Free Wire Thread Inserts
KATO Tangless® Inserts are precision engineered and have been put through rigorous torque, tension, and vibration tests as well as comprehensive dimensional inspections and metallurgical analysis in attaining their MIL Spec qualifications. KATO® inserts have been thoroughly tested by an independent testing laboratory and are certified to conform to NASM8846.
In addition, KATO® inserts and tools are in conformance with the following military, aerospace, and commercial specifications:
Unified Thread Sizes
Standards & Specification | Description |
A-A-59158 | Tools for Inserting and Extracting Helical Coil Wire Screw Thread Inserts |
AS7245 | Insert, Screw Thread, Helical Coil, CRES, Procurement Specification |
AS7246 | Insert, Screw Thread, Helical Coil, Corrosion and Heat Resistant Alloy (Inconel), procurement spec. |
NAS1130 | Insert, Screw Thread, Helical Coil, Tangless |
NASM122076-122275 | Insert, Screw Thread, Helical Coil, Free Running, Coarse Thread |
NASM124651-124850 | Insert, Screw Thread, Helical Coil, Free Running, Fine Thread |
NASM21209 | Insert, Screw Thread, Helical Coil, Self-Locking, Coarse and Fine Thread |
NASM33537 | Insert, Screw Thread, Helical Coil, Inch Series, Coarse and Fine Thread, Standard Assembly Dims |
NASM8846 | Insert, Screw Thread, Helical Coil, Unified Series, Procurement Specification |
Metric Thread Sizes
Standards & Specification | Description |
NA0276 | Insert, Screw Thread, Helical Coil, Free Running and Self-Locking, Metric, Tangless |
MA1565 | Tools for Inserting and Extracting Helical Coil Wire Screw Thread Inserts |
MA1567 | Insert, Screw Thread, Helical Coil, Metric Series, Standard Assembly Dims. |
MA3279 | Insert, Screw Thread, Helical Coil, Free Running, Metric Series, Uncoated |
MA3280 | Insert, Screw Thread, Helical Coil, Free Running, Metric Series, Dry Film Lubricated |
MA3281 | Insert, Screw Thread, Helical Coil, Free Running, Metric Series, Cadmium Plated |
MA3329 | Insert, Screw Thread, Helical Coil, Self-Locking, Metric Series, Uncoated |
MA3330 | Insert, Screw Thread, Helical Coil, Self-Locking, Metric Series, Dry Film Lubricated |
MA3331 | Insert, Screw Thread, Helical Coil, Self-Locking, Metric Series, Cadmium Plated |
AGS Standards
KATO® Inserts are AGS3700-3799 Qualified.
The AGS3700-3799 specification, formerly owned by the Society of British Aerospace Companies (SBAC), is for wire thread inserts made from Nimonic 90 material and silver plated to be used in high temperature applications by world-renowned aerospace companies.
AGS3706 | AGS3707 |
AGS3708 | AGS3720 |
AGS3731 | AGS3732 |
AGS3733 | AGS3757 |
AGS3781 | AGS3782 |
AGS3783 |

KATO Tangless® Inserts
- The bi-directional design and ease of installation of our Tangless® inserts save manufacturers considerable time and production costs.
- Designed to eliminate foreign object debris (FOD), making these inserts reusable, waste-free and imperative as manufactures seek sustainable alternatives.
- Available in unified and metric sizes, a wide range of materials and industry-leading protective finishes.
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