Legacy Threading
Legacy & obsolete threading inserts.
GNEX • LDS • TNMA • TNMC
We specialize in legacy and obsolete carbide threading inserts, supporting discontinued tool systems and specialty threadforms including GNEX, LDS, TNMA, and TNMC. Whether you’re maintaining classic equipment or rescuing a custom process, our inventory and cross-reference network bring the past back online.
Why legacy threading still matters
Modern catalogs move fast. Machines don’t.
NOS (New Old Stock) threading inserts
Discontinued and specialty geometries
Cross-referenced modern equivalents
Technical guidance
Thousands of shops still rely on proven threading systems that were never meant to vanish. Our mission is to keep those systems alive.
Legacy insert families we support
GNEX — External Threading
Classic external threading geometry for steel, stainless, and alloy work. Common sizes include GNEX-3, GNEX-4, and GNEX-5. Compatible replacements available.
GNEX-3 • GNEX-4 • GNEX-5LDS — Internal Threading
Compact internal threading for tight bores and legacy boring systems. We stock LDS-3, LDS-4, and related profiles.
LDS-3 • LDS-4TNMA — Turning & Threading
Negative-rake triangular inserts for rugged turning and threading operations. Popular formats include TNMA-43, TNMA-332, and TNMA-431.
TNMA-43 • TNMA-332 • TNMA-431TNMC — Precision Threading
Positive-edge triangular inserts optimized for fine pitch and finish threading. Commonly sourced as TNMC-332, TNMC-43, and equivalent insert codes.
TNMC-332 • TNMC-43Specialty & obsolete threadforms
We routinely supply tooling for:
If your part number doesn’t appear in any modern catalog — you are exactly where you should be.
Cross-reference & replacement support
Send us your obsolete part number, print code, or a clear photo of the insert. Our technical team can help identify:
Direct replacements
Compatible modern ISO equivalents
Alternative geometries that preserve thread integrity
Threading insert brands & compatibility
We supply carbide threading inserts from trusted manufacturers, along with compatible equivalents for discontinued tooling systems.
Why Great Lakes Carbide Supply
Hard-to-find legacy threading inserts in stock
Trusted Canadian distributor
NOS and modern equivalent sourcing
Fast shipping across North America
Technical support
Request a quote or cross-reference
Looking for a specific GNEX, LDS, TNMA, or TNMC insert? Email your part number, photo, or print. We’ll check stock or provide a compatible equivalent.