Square Nuts Manufacturer
MT.BOLTS manufactures Square Nuts, which are four-sided fastening components designed to be used with bolts, screws, and studs to securely fasten components in mechanical assemblies. The square shape offers greater surface contact with the part being fastened, providing increased resistance to loosening under vibration. Square nuts are ideal for use in tight clearances, channels, or applications requiring antique or traditional aesthetics. MT.BOLTS supplies square nuts in a range of materials, thread types, sizes, and surface finishes for industrial, construction, and specialty applications.
- System of Measurement:
- Metric (M6–M64) | Imperial (1/4″ to 2.5″)
- Height Range (Thickness):
- Metric: 4 mm to 60 mm
- Imperial: 5/32″ to 2-3/8″
(Varies based on standard and nut type) - Thread Pitch:
- Metric: Coarse (default), Fine (available)
- Imperial: UNC, UNF
- Thread Type:
- Right-hand thread (standard)
- Left-hand thread (optional on request)
- Nut Types:
- Standard Square Nut
- Heavy Square Nut
- Slotted Square Nut
- Weld Square Nut
- Machine Square Nut
- Custom-profile Square Nut
Square Nuts Material Types
MT.BOLTS supplies carbon steel, stainless steel, duplex steel, and nickel-based alloy Square Nuts, meeting the demanding requirements of chemical, marine, and high-temperature environments, compliant with various international standards.
| Material Category | Common Grades/Models | Description |
| Carbon Steel | ASTM A307, A325, A490 | High strength and cost-effective, suitable for general structures; requires anti-corrosion coating. |
| Stainless Steel | 304 (A2), 316 (A4), 321, 410 | Excellent corrosion resistance; widely used in food, chemical, and construction industries |
| Duplex Stainless Steel | UNS S31803/S32205 (F51), UNS S32750 (F53) | High strength with superior chloride corrosion resistance; used in seawater, petrochemical, and paper industries |
| Monel Alloys | Monel 400, Monel K500 | Excellent seawater corrosion resistance and mechanical strength; used in marine engineering and pump systems |
| Hastelloy Alloys | Hastelloy C276, C22, B2, X | Excellent resistance to strong acids and oxidizing media; widely used in chemical equipment and flue gas desulfurization |
| Inconel Alloys | Inconel 600, 625, 718 | Resistant to high temperature, pressure, and corrosion; used in heat exchangers, aerospace, and nuclear industries |
| Incoloy Alloys | Incoloy 800, 825, 925 | Ideal for high-temperature acidic environments; widely used in petroleum refining and heat treating systems |
| Nickel Alloys | Nickel 200, 201 | Pure or high-nickel alloys with excellent conductivity and alkali resistance; used in electronics and chemical applications |
Square Nuts System of Measurement
Square nuts are produced in both metric and imperial systems, adapted to global industrial needs:
- Metric Sizes: M4 to M64
- Imperial Sizes: 1/4″ to 2-1/2″
- Height Range:
- Metric: 3 mm to 30 mm
- Imperial: 1/8″ to 1-1/4″
- Thread Pitch:
- Metric: Coarse (standard), Fine available on request
- Imperial: UNC (Unified Coarse), UNF (Unified Fine)
- Thread Direction:
- Right-hand thread (standard)
- Left-hand thread (optional)
Square Nuts Common Standards
Square nuts are manufactured according to the following international standards:
DIN 557 – Standard metric square nut (full height)
DIN 562 – Thin square nut (low-profile)
ASME B18.2.2 – Inch-series square nuts
ASTM A563 – Mechanical requirements for carbon/alloy steel square nuts
ASTM A194 – High-pressure, high-temperature square nuts
ISO 4034 / 4035 – Metric general-purpose nut specs
GB/T 39 / GB/T 6170 – Chinese national standards
OEM / Custom standards – For specialty industries and assemblies
Square Nuts Surface Finishes
Square nuts are available in various finishes to improve corrosion resistance, appearance, or lubrication:
Plain (Uncoated) – Standard finish for dry indoor use
Zinc-Plated – Clear or yellow, provides moderate corrosion protection
Hot-Dip Galvanized – Excellent for outdoor or structural applications
Black Oxide – Low-friction finish with minimal corrosion resistance
Phosphate-Coated – Common in automotive and machinery applications
PTFE-Coated – Chemical-resistant, low-friction for specialty uses
Passivated (Stainless Steel) – Enhanced corrosion resistance
Custom Finishes – Per project or industry requirement
Why Choose MT.BOLTS
- Material Diversity
- Standardized Production
- Ample Inventory
- Competitive Pricing
- Low-MOQ Customization
Benefits and Limitations of Square Nuts
Benefits:
Large Bearing Surface – Reduces risk of deformation, distributes load evenly
Good Tool Grip – Four sides offer more surface area for wrench contact
Easy Assembly in Channels – Ideal for use with square holes or slots
Traditional Appearance – Used in heritage or restoration projects
Limitations:
Bulky Profile – Takes up more space than hex nuts
Lower Availability – Less common than hex nuts in general retail
Limited Torque Capabilities – May not be suitable for high-strength bolting without matching washer
Prone to Corrosion – Sharp corners may trap moisture if not properly finished
Send Us A Message
Square Nuts Applications
Square nuts are used in a wide range of structural and mechanical settings, especially where load distribution or alignment is important:
Metal Channels and Framing Systems
Furniture and Woodworking Assemblies
Railings, Scaffolding, and Construction Fixtures
Machinery and Equipment Fastening
Antique, Decorative, or Restoration Projects
Electrical Panel Mounting
Solar Racking and Bracket Systems
FAQ About Square Nuts
Square nuts provide a larger surface area and are easier to grip with pliers or in channel/slotted assemblies.
Yes, flat washers are often recommended to protect the workpiece and distribute load.
Yes, in both 304 and 316 grades for corrosion resistance.
Typically no — square nuts are best suited for manual or low-speed tools due to their shape.
Not necessarily — strength depends on material and thickness, though square nuts offer more surface contact.
Related Products
17-4 PH Stainless Steel Fasteners
17-4 PH Stainless Steel Fasteners Supplier MT.BOLTS manufactures 17-4 PH stainless steel fasteners using high-quality precipitation-hardening stainless steel. These fasteners
18-8 stainless steel fasteners
18-8 Stainless Steel Fasteners Supplier MT.BOLTS manufactures 18-8 stainless steel fasteners using high-quality austenitic stainless steel grades such as 304,
ASTM A307 Bolts
ASTM A307 Bolts Supplier MT.BOLTS manufactures ASTM A307 carbon steel bolts using high-quality low-carbon steel materials. These bolts offer reliable