The Thin Hex Nut (commonly known as a hex jam nut, low-profile hex nut, thin locknut, or DIN 439 / ISO 4035 fastener) is a reduced-height internally threaded fastener designed for space-restricted clearance applications or used as a secondary locking nut to prevent primary joint loosening under severe vibration. Featuring a thickness approximately half that of a standard DIN 934 hex nut (m ≈ 0.5d), our thin jam nuts are manufactured in carbon steel (Property Classes 04, 05, 4, and 8) and austenitic stainless steel (SS304/A2-70 and SS316/A4-80) in strict compliance with global ISO standards.
Technical Specifications of Thin Hex Jam Nuts
Thin hex jam nuts are engineered primarily to load in tension against a full-height hex nut (jamming mechanism) or to secure unthreaded components where axial clearance is limited. Standard DIN 439 Form B features double-sided chamfered bearing faces for clean aesthetic integration.
| Property Class / Grade | Raw Material Base | Proof Stress Rating | Mechanical Function | Available Surface Treatments |
|---|---|---|---|---|
| Class 04 / Class 4 | Low Carbon Steel (Q195 / Q235B) | 380 – 400 N/mm² | Standard Jamming & Light Low-Profile Fastening | Plain Black, Electro-Zinc Plated (Blue-White / Yellow) |
| Class 05 / Class 8 | Medium Carbon Steel (45# Quenched) | 500 – 800 N/mm² | High-Tensile Secondary Locking against Class 8.8 Bolts | Black Oxide, Electro-Zinc, Hot-Dip Galvanized (HDG) |
| Stainless A2-70 / A2-80 | Austenitic Stainless Steel SS304 (1.4301) | 700 – 800 N/mm² | Corrosion Resistant Jamming in Food & Outdoor Equipment | Passivated Clean Natural / Electropolished |
| Stainless A4-70 / A4-80 | Austenitic Stainless Steel SS316 (1.4401) | 700 – 800 N/mm² | Acid & Salt Spray Resistant Jamming in Marine Engineering | Passivated Clean Natural / Electropolished |
Precision Cold Forming and Internal Tapping Process
At our manufacturing facility in Handan, China, thin hex jam nuts undergo multi-station cold heading, high-precision thread tapping, controlled heat treatment, and surface passivating:
- Low-Profile Cold Heading: High-speed multi-station former machinery punches wire rod into precise thin hex geometry, establishing clean 15°–30° bearing face chamfers.
- Precision Internal Tapping: High-accuracy tapping spindles thread metric 6H course or fine pitches, ensuring smooth hand-threading without thread binding or thread stripping.
- Thermal Quenching & Tempering (Class 05 / Class 8): Medium carbon thin nuts are heat-treated in continuous mesh-belt furnaces to enhance proof load capacity without brittleness.
- Surface Coating & Chemical Passivation: Electro-zinc plating (5–12 µm), black oxidation oiling, or chemical acid passivation for stainless steel items.
Versatile Engineering Applications of Thin Hex Jam Nuts
Thin hex jam nuts serve as essential secondary locking elements or primary fasteners in space-restricted assemblies:
- Anti-Loosening Jam Nut Mechanism: Threaded onto a bolt or rod prior to a standard DIN 934 hex nut; tightening the main nut against the jam nut creates opposing thread flank pressure that prevents loosening under dynamic vibration.
- Low-Clearance Electrical & Switchgear Cabinets: Fastening electrical terminals, potentiometer shafts, and control panel switches where axial protrusion must be minimized.
- Pneumatic & Hydraulic Cylinder Rods: Securing clevis ends and rod eye joints on hydraulic cylinder piston shafts.
Quality Assurance and Export Packaging for Thin Hex Jam Nuts
Handan YiHao Fastener enforces strict Quality Assurance (QA) standards for all overseas export shipments. Inspection procedures include 100% thread plug gauge go/no-go checks, nut thickness gauge measurement, proof stress testing, and salt spray validation.
All export orders are bulk packed in heavy-duty 25kg inner cartons, neatly stacked on ISPM 15 compliant fumigated wooden pallets, and wrapped in protective stretch film for safe ocean freight.
Request Factory Direct Pricing for Thin Hex Jam Nuts
Looking for a trusted manufacturer in Handan, China for carbon steel or stainless steel thin hex jam nuts (Class 04, Class 05, Class 4, Class 8, SS304, SS316, DIN 439 / ISO 4035)? Contact Handan YiHao Fastener today for technical datasheets, fine thread pitch options, sample shipments, and direct bulk export quotes.
