Internal External Thread Adapters For Industrial And Civil
Connections
Internal & External Thread Adapters are precision connectors with
internal threads on one end and external threads on the other.
Through differentiated adaptation of thread specifications, they
achieve rigid docking of components with different sizes and types,
and are widely used in pipelines, machinery, home furnishing and
other scenarios requiring reducing conversion and thread
compatibility. Their structural design focuses on thread matching
accuracy and force transmission stability, making them core
components for solving "thread incompatibility" in industrial and
civil connections.
I. Core Structure and Design Highlights
- Reducing Thread Adaptation Design: One end features internal threads (for connecting bolts, screws
or components with external threads), and the other end has
external threads (for adapting to female parts, sleeves or
interfaces with internal threads). The thread precision reaches 6H
(internal)/6g (external) with complete thread profiles and no
broken teeth, enabling same-diameter (e.g., internal M10 * external
M10) or reducing (e.g., internal M8 * external M12) conversion,
compatible with metric, imperial and other thread standards.
- Mechanical Transition Optimization: The middle part of the adapter adopts a cylindrical or hexagonal
transition structure. Internal/external threads are connected to
the transition section via arc chamfers (R≥0.5mm) to reduce stress
concentration. The integral cold heading or machined forming
ensures no splicing gaps, with shear strength ≥300MPa (for carbon
steel materials), ensuring stable force transmission.
- Optional Sealing Design: Some models are equipped with annular sealing grooves at the
thread root, which can be fitted with O-rings (nitrile
rubber/fluororubber) or coated with sealant to achieve leak-proof
connections for fluid/gas media, suitable for pressure scenarios
such as water pipes and air pipes.
II. Core Parameter Specifications
| Parameter Category | Specific Parameters | Detailed Description |
|---|
| Thread Standards | Metric (internal M5-M30/external M6-M36), imperial (internal
1/4"-1"/external 3/8"-1 1/4"), supporting customization of
coarse/fine threads. | Threads comply with GB/T 192, ISO 261 or ANSI B1.1 standards with a
60° thread angle, ensuring smooth engagement with adapted
components. |
| Materials and Surface Treatments | Base Materials | Carbon Steel (Q235/45#): Suitable for dry indoor, medium-low load scenarios with economic
cost; Stainless Steel (304/316): Salt spray resistance ≥72 hours, corrosion-resistant, used in
humid, outdoor or mild chemical environments; Brass (H59/H62): Good thermal conductivity, non-magnetic, suitable for civil
scenarios such as water pipes and gas pipelines. |
| Surface Treatments | Zinc Plating (color zinc/white zinc): Zinc layer 8-12μm, salt spray resistance ≥48 hours, basic
anti-corrosion for carbon steel parts; Stainless Steel Passivation: Enhances rust resistance while maintaining the metal's natural
color; Chrome Plating: Hardness ≥800HV, wear-resistant and aesthetic, suitable for
exposed decorative scenarios. |
| Precision and Dimensions | Thread Tolerance | Internal thread 6H, external thread 6g, with a fitting gap ≤0.05mm
to ensure no jamming. |
| Length Specifications | Regular length 15-50mm (customizable), with transition section
diameter ≥ external thread major diameter to ensure structural
strength. |
III. Core Performance Advantages
- Flexible Reducing Adaptation: Internal and external thread specifications can be customized as
needed (e.g., internal fine thread → external coarse thread, metric
→ imperial), directly solving thread mismatch issues of bolts,
pipes, joints and other components without the need for additional
transition parts, reducing connection costs.
- Reliable Connection Rigidity: The integrally formed structure has no weak points. With
sufficient thread engagement (engagement length ≥1.2 times the
thread diameter), the static tensile load of M10 carbon steel
adapters is ≥10kN, which is not easy to loosen in vibrating
environments.
- Convenient and Efficient Installation: No professional tools are required; connection can be completed
by tightening with a wrench, compatible with conventional fastening
processes. The hexagonal transition section facilitates torque
application, with installation efficiency 50% higher than welding
or adhesive connections.
- Strong Scene Compatibility: Optional sealing design adapts to fluid scenarios; diverse
materials cover dry, humid, corrosive and other environments,
balancing industrial strength and civil safety.
IV. Typical Application Scenarios
- Home Furnishing and Lighting: Reducing connection of furniture brackets (e.g., docking of table
leg screws and beam sleeves), thread conversion of chandelier
suspension rods (adapting to different specifications of lamp
holders and hanging rods). Brass or zinc-plated carbon steel models
are suitable for dry indoor environments.
- Plumbing and Water/Electric Systems: Reducing of water/air pipe diameters (e.g., DN15 internal thread
to DN20 external thread), adaptation of water heater interfaces.
Stainless steel models with sealing grooves can prevent water/gas
leakage.
- Machinery and Equipment: Thread docking of motor and reducer shaft systems, pipeline
connection of instruments. High-precision threads ensure
concentricity and reduce operational vibration.
- Decoration and Display: Fixing of shelf columns and beams, connection of exhibition prop
accessories. Chrome-plated models balance connection function and
appearance texture.
V. Installation and Maintenance Recommendations
- Installation Points: Clean oil stains and burrs on the thread surface before
installation to ensure no impurity jamming. For load-bearing
scenarios, it is recommended to apply anti-loosening glue (e.g.,
thread locker) on the threads or use double nuts for
anti-loosening.
- Maintenance Notes: Regularly check the anti-corrosion layer of carbon steel parts;
if rust is found, clean it in time and touch up with anti-rust
agent. For fluid scenarios, regularly check the sealing status; if
leakage occurs, replace the seals or adapters.
With the core advantages of "precise adaptation + rigid connection
+ scene flexibility", internal & external thread adapters provide
an efficient solution to solve thread compatibility issues in
industrial and civil connections, balancing connection reliability,
installation convenience and cost-effectiveness, and are
indispensable basic connectors in machinery, home furnishing, water
and electricity fields.