Hex Nuts
What Are Hex Nuts?
Hex nuts—also called finished hex nuts—are six-sided nuts used with bolts, machine screws, and threaded rod to clamp materials together. The hexagonal shape offers excellent tool access from multiple angles for quick tightening in assemblies ranging from general construction and machinery to automotive and electrical work.
Why Choose Hex Nuts?
- Versatile fit: Works with standard bolt grades and machine screw threads in inch and metric sizing.
- Fast tool engagement: Six flat faces provide reliable wrench and socket contact in tight spaces.
- Wide strength range: Available in low-carbon, medium-carbon, alloy steel, stainless, brass, aluminum, and more.
- Finish options: Plain/oil, zinc plated, hot-dip galvanized, black oxide, and decorative chrome to match conditions.
- Standards compliant: Offered to common ASME/ANSI, SAE, ISO/DIN specs for predictable fit and torque.
Common Hex Nut Types We Offer
- Finished Hex Nuts: General-purpose six-sided nuts for bolts and machine screws.
- Heavy Hex Nuts: Larger across-flats and thickness for higher clamp loads and structural use.
- Hex Jam Nuts: Thinner lock-nuts used to jam against a standard nut for vibration resistance or for limited clearance.
- Machine Screw Hex Nuts: Small-diameter, fine-thread nuts for electronics and light hardware.
- Slotted Hex Nuts: Use with cotter pins on drilled bolts or shafts for positive mechanical locking.
- Structural/High-strength Hex Nuts: For A325/A490 and similar structural bolt assemblies.
Materials & Finishes
- Stainless Steel 18-8 / 304: General corrosion resistance for most environments.
- Stainless Steel 316: Enhanced resistance for marine, chemical, or chloride exposure.
- Carbon & Alloy Steel: Broad strength range; choose zinc, black oxide, or hot-dip galvanized for protection.
- Hot-Dip Galvanized: Thick zinc layer and oversized threads for outdoor structural applications.
- Zinc Plated: Economical indoor corrosion protection with a bright finish.
- Black Oxide: Low-glare cosmetic finish with light corrosion resistance (usually oiled).
- Brass / Silicon Bronze / Aluminum: Non-magnetic or decorative options; good conductivity (brass/bronze).
- Chrome Plated: Decorative, durable surface for visible assemblies.
How to Select the Right Hex Nut
- Match the thread: Diameter and pitch must match the mating bolt or screw (e.g., 1/4"-20, M8-1.25).
- Choose the grade: Align nut proof strength with bolt grade (e.g., Grade 5/8, Class 8/10, A2/A4 stainless).
- Pick the profile: Standard, jam (thin), heavy hex, or slotted depending on clearance and locking needs.
- Environment: Use stainless or hot-dip galvanized outdoors; zinc or black oxide for indoor/dry; 316 for marine.
- Washer style: Add flat and lock washers when needed for finish protection or vibration resistance.
Common Applications
- General fabrication, MRO, and OEM assembly
- Automotive, trucks, and equipment
- HVAC, electrical panels, and enclosures
- Framing, racking, and structural connections (with proper heavy/structural specs)
- Furniture, fixtures, and architectural hardware
Installation Tips for Hex Nuts
- Start threads by hand to avoid cross-threading; then finish with the correct wrench or socket.
- Tighten to the specified torque for the bolt grade and lubrication condition; don’t exceed proof strength.
- Use thread-locking methods if required: jam nuts, prevailing-torque nuts, threadlocker, or slotted nut + cotter pin.
- For hot-dip galvanized fasteners, confirm compatible “oversize” threading on the nut and bolt.
- Protect finishes with washers when clamping painted or soft materials.
Hex Nuts FAQs
A six-sided (hexagonal) nut that threads onto a bolt, screw, or stud to clamp parts together. The six flats make wrenching easy from multiple angles.
Heavy hex nuts are larger across-flats and thicker than finished hex nuts, providing higher clamp load capacity and typically used with high-strength or structural bolts.
Use a jam (thin) nut to lock a standard nut in place (jam-nut method) or where vertical clearance is limited and a low profile is required.
18-8/304 stainless resists most corrosion; however, 316 stainless is preferred in marine or chloride environments for improved pitting resistance.
Avoid mixing dissimilar metals outdoors; galvanic corrosion can occur. Match materials when possible or isolate with compatible washers/spacers.
Match the bolt’s diameter and pitch exactly (e.g., 1/4"-20, 3/8"-16, M6-1.0, M10-1.5). Inch and metric are not interchangeable.
Select a nut with equal or higher proof strength than the bolt (e.g., Grade 5 bolt → Grade 5/8 nut; Class 8.8 bolt → Class 8/10 nut). Follow the relevant standard.
Often recommended. Flat washers protect surfaces and distribute load; lock washers or serrated/flange hardware may add vibration resistance.
Tighten to the specified torque for the bolt size, grade, lubrication, and joint conditions. Over-torque can strip threads or yield the fastener.
Slotted (castle) nuts are used with a cotter pin through a drilled bolt or shaft to mechanically lock the assembly—common in wheel, hitch, and machinery pivots.
Light, short-term outdoor exposure is usually fine, but for sustained weathering use hot-dip galvanized or stainless steel.
HDG hardware uses oversize internal threads to accommodate the coating. Ensure both nut and bolt are HDG-compatible and to the same standard.
They use different diameters and thread pitches (e.g., 1/4"-20 vs M6-1.0). They are not cross-compatible, always match systems.
No. Brass and bronze are typically chosen for conductivity, aesthetics, or corrosion resistance in specific environments—not for high structural loads.