Hex Jam Nuts
A hex jam nut is a thin version of a standard hex nut — roughly half the height. Its main job is to lock another nut in place (the double-nut or jam-nut method), to set and hold position on threaded rod or a turnbuckle, or to fit where a full-height nut won’t. Eugene Fastener & Supply stocks hex jam nuts in Grade 2, Grade 5, and Grade 8 steel, 18-8 stainless, and metric, in coarse and fine threads.
Because they’re thinner, jam nuts carry less load than a standard nut, so they’re used as a secondary locking element rather than the primary fastener. Choose the grade to match your bolt and the locking method to match the joint. We sell by the piece or in bulk, cross-reference part numbers, and ship same day on orders placed before 2pm Pacific.
Goes Well With
Hex Jam Nuts — Thin Nuts in Every Grade
Need jam nuts for a production run or a specific grade?
Get Job Pricing / Submittals Email Sales
Hex Jam Nuts by Grade & Material
- Grade 2 Hex Jam Nuts — general-purpose thin nuts.
- Grade 5 Hex Jam Nuts — medium strength.
- Grade 8 Hex Jam Nuts — high strength.
- Stainless Hex Jam Nuts — 18-8 corrosion resistance.
- Metric Hex Jam Nuts — coarse and fine pitch.
How to Use a Jam Nut
- Locking another nut (double-nut method): thread on the jam nut, then the primary nut, and tighten them against each other so they wedge and resist loosening.
- Setting position: lock a fitting, turnbuckle, or stop at a set point on threaded rod.
- Tight clearances: use where a full-height nut won’t fit.
Hex Jam Nut FAQ
What is a jam nut?
A jam nut is a thin hex nut, about half the height of a standard hex nut. It’s used to lock another nut in place, to set and hold position on threaded rod, or to fit in tight clearances. Because it’s thinner it carries less load, so it serves as a secondary locking element rather than the primary fastener.
How do you use two nuts to lock a joint?
This is the double-nut or jam-nut method: thread on the first (jam) nut, then the primary nut on top, then tighten the two against each other. They wedge together on the threads and resist loosening from vibration without a separate lock nut or adhesive.
Which nut goes on first, the jam nut or the regular nut?
By the textbook (load-distribution) method the thin jam nut goes on first (against the joint) and the thicker nut on top, because the top nut carries the load once jammed. In common field practice many installers reverse it. Either way, the key is tightening the two nuts firmly against each other.
How thick is a jam nut?
A hex jam nut is roughly half to about 60% the height of a standard hex nut of the same diameter. That lower profile is what lets it fit tight spaces and act as a locking nut against a primary nut.
What grades and materials are available?
Grade 2, Grade 5, and Grade 8 steel, 18-8 stainless, and metric, in coarse and fine threads. Match the grade to your bolt.
Do you sell by the piece and cross-reference part numbers?
Both by the piece and in bulk. Send any manufacturer or DIN part number and we’ll match it, usually same business day.
Why Buy Jam Nuts from Eugene Fastener
- Every grade — Grade 2/5/8, stainless, and metric.
- By the piece or in bulk, with cross-reference and grade matching.
- Same-day shipping before 2pm Pacific.
- Since 1969 — serving Pacific Northwest industry for over 55 years.
Jam nuts pair with our hex nuts, threaded rod and studs, and turnbuckles. For dedicated vibration resistance, see our lock nuts, or browse all nut types. Contact our sales team for grade matching or bulk pricing. Eugene Fastener & Supply — serving the Pacific Northwest since 1969.