INDUSTRY COMPONENT

Coupling Nut

A threaded fastener used to connect two shafts or components in coupling mechanisms for torque transmission.

Component Specifications

Definition
A coupling nut is a cylindrical fastener with internal threading designed to join two externally threaded rods, shafts, or components end-to-end. It serves as a critical component in coupling mechanisms, providing a secure mechanical connection that transmits torque, rotational motion, and axial loads between connected elements while maintaining alignment and allowing for adjustable length or tension in the assembly.
Working Principle
The coupling nut operates on the principle of threaded engagement, where its internal threads mate with external threads on two separate components. When tightened, it creates a clamping force that securely joins the components, enabling torque transmission through friction and mechanical interlock. The nut distributes loads evenly across the threaded interface, preventing separation under operational stresses while allowing for disassembly when required.
Materials
Typically manufactured from carbon steel (Grade 5 or 8), alloy steel (4140, 4340), stainless steel (304, 316), or brass. Materials are selected based on strength requirements, corrosion resistance, and environmental conditions. Common specifications include ASTM A193 for alloy steel, ASTM A276 for stainless steel, and SAE J429 for carbon steel grades.
Technical Parameters
ParameterTypical rangeNotes & selection driver
Length20mm to 200mm (varies with application)
HardnessHRC 22-35 for steel variants
Thread SizeM6 to M64 or equivalent imperial sizes
Thread PitchStandard coarse or fine threads
Surface FinishZinc-plated, hot-dip galvanized, or plain
Tensile Strength400 MPa to 1200 MPa depending on material

Ranges are indicative industry figures for RFQ preparation, not a supplier commitment. Confirm every value and standard with the legal manufacturer before ordering.

Standards
ISO 4032, DIN 6334, ASME B18.2.2, ANSI B1.1

Parent Products

This component is used in the following industrial products

Engineering Analysis

Risks & Mitigation
  • Thread stripping due to over-torquing
  • Corrosion in harsh environments
  • Misalignment causing uneven load distribution
  • Fatigue failure under cyclic loading
FMEA Triads
Trigger: Incorrect torque application during installation
Failure: Thread stripping or nut cracking
Mitigation: Use calibrated torque wrenches and follow manufacturer specifications
Trigger: Exposure to corrosive chemicals or moisture
Failure: Corrosion leading to weakened structural integrity
Mitigation: Select corrosion-resistant materials (e.g., stainless steel) or apply protective coatings
Trigger: Misalignment of connected shafts
Failure: Uneven wear and premature failure
Mitigation: Ensure precise alignment during assembly and use alignment tools

Industrial Ecosystem

Compatible With

Typical Suppliers & Equivalents

Compliance & Inspection

Tolerance
Thread tolerance per ISO 965-1 (6g for internal threads), dimensional tolerance per ISO 2768-m
Test Method
Torque testing per ASTM F606, tensile testing per ASTM A370, corrosion resistance testing per ASTM B117

Procurement Evaluation Criteria

A practical evidence checklist for RFQ preparation and supplier evaluation.

Technical documentation
Request current drawings, revision history, and a signed specification sheet.
Manufacturing capability
Verify equipment lists, process limits, capacity, and representative production evidence.
Inspection readiness
Confirm test methods, calibrated equipment, sampling plans, and traceable reports.
Supplier transparency
Check the legal entity, factory address, ownership, certifications, and direct contacts.

CNFX does not score or rank suppliers. Buyers must verify all claims and documents with the legal manufacturer before ordering.

Manufacturers of Coupling Nut

3 companies list this product among what they make. Company figures are quoted from each company's own website; every card states where the relationship came from.

Haiyan Bolt Co., Ltd.
Jiaxing, Zhejiang, CN
Also makes: Nut, Self-Tapping Screw, Furniture Hinge and 9 more
Listed on the company's own website · profile compiled by CNFX from public sources
Ningbo Teng Qi Fasteners Co., Ltd
Ningbo, Zhejiang, CN
ISO 9001:2015 IATF 16949
Also makes: Nut, Laser Cutting System, Control System and 1 more
Listed on the company's own website · profile compiled by CNFX from public sources
ZENGO Airandus
Ningbo, Zhejiang, CN
Also makes: Ventilation Fan, Centrifugal Fan, Flexible Duct and 9 more
Listed on the company's own website · profile compiled by CNFX from public sources

Manufacturer listings support early research and capability understanding. They are not certification, ranking, or transaction guarantees.

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Shaft Bearing
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Seal Groove
Precision-machined groove in aluminum bearing housings designed to accommodate sealing elements for fluid containment and contamination prevention.

Frequently Asked Questions

What is the primary function of a coupling nut?

To securely join two threaded rods or shafts end-to-end, enabling torque transmission and maintaining alignment in mechanical systems.

How do you select the right coupling nut material?

Choose based on application requirements: carbon steel for general use, alloy steel for high strength, stainless steel for corrosion resistance, and brass for non-sparking environments.

Can coupling nuts be reused?

Yes, if undamaged and threads are intact, but inspect for wear, corrosion, or deformation before reuse to ensure reliability.

Data Basis

Editorial classification, named public sources where available, and source-reviewed manufacturer records. See the editorial policy.

Preliminary Technical Classification
This page supports structured research, RFQ preparation, and supplier evaluation. It does not replace buyer-led supplier qualification, standards review, or technical approval.

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