Our Carbon Steel Hex Nuts are made to ASTM A194 standards, using low-carbon steel with 0.25-0.3% carbon and 0.6-1.05% manganese. This mix gives them the right balance of strength and ductility-tensile strength sits at 550-700 MPa, so they hold tight under pressure without cracking.
They're designed to pair perfectly with carbon steel bolts, with UNC threads (ASME B1.1) that fit smoothly but lock securely. We tested them by tightening and loosening 50 times, and they didn't strip or wear-ideal for construction, machinery, or any general industrial use where corrosion isn't a major threat. For wholesalers, they're a cost-effective staple that covers most basic fastening needs.
We offer two finishes: plain (mill finish) for indoor use and black oxide coated (per ASTM D769) for extra rust protection during storage. The black oxide layer is thin but tough, passing 48-hour humidity tests (ASTM D1748) with no red rust.
Our threading is precise-Class 2B fit (ASME B1.1) means they screw on easily but won't loosen on their own. We use cold forging to shape the hex heads, which keeps the metal strong and avoids weak spots. Every nut gets a go/no-go gauge check to make sure threads match standard bolts, and we pack them in plastic bins with dividers to prevent thread damage in transit.
As a Chinese manufacturer with 14 years supplying EU and US hardware markets, we run 10 nut-forming machines and 6 threading lines, churning out 6,000 tons annually. Our raw steel comes from ISO 9001-certified mills, and each batch undergoes a hardness test (Rockwell B 70-85, ASTM E18) to ensure consistency.
We keep 900-1200 tons in stock at our Shanghai warehouse, covering sizes from ΒΌ" to 2" and thicknesses 5mm to 30mm. Inventory updates hourly on our website, and FOB Shanghai shipments for in-stock nuts leave within 48 hours-perfect for when your customers need quick restocks.
Orders over 100 tons get a 5.5% discount, plus free black oxide coating.
Our guarantee: If any Carbon Steel Hex Nut strips during normal installation or doesn't meet ASME B18.2.2 dimensions, we'll replace them within 4 days and cover all shipping costs. We also lock prices for 30 days on confirmed orders, so you don't have to worry about sudden cost spikes eating into your margins.
Carbon steel (varies by grade, including:
6-sided hexagonal head (standardized for wrench compatibility); head width across flats (WAF) and thickness proportional to thread size (e.g., 1/4" nut has ~7/16" WAF in imperial standards).
Mechanical Properties
Mechanical Properties
Thread Standards
Imperial: Unified National Coarse (UNC) or Fine (UNF) per ASME B1.1.
Metric: Coarse (ISO metric) or fine threads per ISO 898-2.
Sizes: 1/4"β4" (imperial); M5βM64 (metric), matching bolt diameters.
Types/Variants
Hex Nuts (Standard): Most common; 6-sided, for general fastening.
Heavy Hex Nuts: Larger WAF and thickness for greater bearing surface (used in structural applications).
Slotted Hex Nuts: With slots for cotter pins to prevent loosening (vibration-prone environments).
Lock Hex Nuts: With nylon inserts or deformed threads to resist loosening (no cotter pin needed).
Surface Finish
Plain (black oxide): Basic corrosion resistance for dry, indoor use.
Zinc-plated: Improved protection in mild humidity or outdoor settings (blue, clear, or yellow chromate finishes).
Hot-dip galvanized: Thick zinc coating for harsh environments (construction, marine).
Electroplated: Uniform coating for aesthetic and corrosion needs.
Applications
Paired with carbon steel hex bolts in construction (structural joints, concrete formwork).
Machinery: Securing components in engines, pumps, and industrial equipment.
Automotive: Fastening parts in chassis, suspension, or engine bays.
Piping: Joining flanges, valves, and low-to-medium pressure systems.
General-purpose: Any application requiring secure, reusable threaded connections.
Key Features
Strength Matching: Designed to pair with carbon steel bolts (nut strength typically slightly lower than bolt to prevent nut failure first).
Versatility: Standard hex design fits universal wrenches/sockets.
Cost-Effective: Carbon steel offers good strength at lower cost than alloy steel nuts.
Reusability: Can be removed and reinstalled in non-permanent joints.
Standards Compliance
Imperial: ASME B18.2.2 (hex nuts), ASTM A563 (carbon steel nuts for structural bolts).
Metric: ISO 4032 (hex nuts), DIN 934 (metric hex nuts).
Low carbon: Often compliant with ASTM A307 (for light-duty use).
Frequently Asked Questions
Q: Do you accept small quantity orders?
A: Yes, we accept small quantity orders. Even for trial orders, we'll provide the same quality and service as bulk orders.
Q: Is there a warranty period for your products? How long is it?
A: Yes, all products have a 12-month warranty. During this period, we'll handle any quality-related issues free of charge.
Q: How long does it take to produce a custom order with special specifications?
A: It usually takes 25-30 days, depending on the complexity of the design. We'll confirm the exact lead time after evaluating your requirements.
