Nuts
Hex Jam Nuts
Half-height nuts for locking against a full nut.
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Jam nuts lock a primary nut or fix a position on threaded rod without adding height.
Manufactured to
Standards.
ASME B18.2.2Nut dimensions
ASTM A194Nut material grades
ASME B1.1Unified inch screw threads
The buyer’s guide
What are hex jam nuts?
A jam nut is a thin hex nut — roughly half standard thickness — with the same across-flats as its full-size partner. Run down against a standard nut and torqued into it, the pair jams the thread and locks against vibration without adhesives or inserts.
- About half the thickness of a finished nut
- Same wrench size as the full nut
- Also used alone where axial space is tight
- All grades and materials we stock
Other names
- Jam nuts
- Half nuts
- Thin nuts
- Lock nuts (loosely — see lock nuts)
Tips for purchasing
- The jam nut goes on first, full nut on top — order both as a set.
- Dimensions per ASME B18.2.2 — confirm by size with estimating.
- Certs on request.
Available in
Materials.
A194 2HA194 2HMA194 4A194 7A194 7MA194 8A194 8MA194 8CA194 8TF880F879F837F594 stainless nuts304 Stainless304L Stainless316 Stainless316L StainlessA193 B8T Class 1A193 B8T Class 2A320 B8T321 StainlessA193 B8C Class 1A193 B8C Class 2A320 B8C347 StainlessA193 B6410 Stainless416 Stainless17-4 PHF468 nonferrous boltsF467 nonferrous nutsInconel 718Inconel X-750Nimonic 80AInconel 725Incoloy 925Incoloy 825Incoloy 800H/HTMonel 400Monel K-500Duplex 2205Super Duplex 2507Zeron 100A193 B8RA193 B8SNitronic 50Nitronic 60A453 660
Representative capabilities — every item is manufactured or certified to your specification. Confirm requirements with our estimating team.
Applications
Locking assembliesAdjustment screws
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