Custom Black Oxide Hex Socket Head Sealing Screws with O-Ring

Short Description:

Custom black oxide hex socket head sealing screws feature an elastomer O-ring positioned beneath the cylindrical head. When properly matched to the mating surface and installed within the specified torque range, the O-ring compresses to help reduce the ingress of moisture, dust, oil and air around the fastening point. Screw dimensions, materials, thread specifications, surface finishes and O-ring compounds can be customized according to drawings, samples and assembly requirements.

Product Detail

Product Tags

Item	Specification
Product Name	Hex Socket Head Sealing Screws with O-Ring
Head Type	Cylindrical Socket Head
Drive Type	Internal Hex Socket
Thread Type	Metric Machine Thread, UNC, UNF or Custom Thread
Thread Structure	Fully Threaded or Partially Threaded
Size	According to Customer Drawings or Samples; Special Sizes Available upon Evaluation
Standard	ISO 4762, DIN 912, ANSI, JIS, GB or Customer Drawing
Material	Carbon Steel, Alloy Steel, Stainless Steel or Other Specified Materials
Strength Grade	Customized According to Material, Drawing and Assembly Requirements
Surface Treatment	Black Oxide; Zinc, Nickel, Dacromet, Geomet and Other Finishes Available
O-Ring Material	NBR, EPDM, Silicone or FKM
O-Ring Color	Red, Black or Customized
Tolerance	According to Drawing and Application Requirements
Custom Service	Size, Head, Thread, O-Ring, Material, Finish, Marking and Packaging
Inspection	Dimensions, Hardness, Torque, Material and Optical Sorting
Application	Enclosures, Sensors, Industrial Equipment, Automotive Components and Outdoor Assemblies
OEM / ODM	Supported

Key Product Features

Integrated O-Ring Seal

The O-ring is positioned beneath the screw head to create a compressed sealing interface during installation.

Controlled Hex Socket Drive

The internal hex drive supports accurate torque application and installation in compact or recessed assembly locations.

Black Protective Finish

The black surface provides a uniform industrial appearance and can offer additional surface protection depending on the selected coating process.

Custom Sealing Configuration

Screw dimensions, O-ring compound, head geometry and sealing contact design can be adjusted to match the mating component.

Typical Uses

Electrical Enclosures

Suitable for control boxes, electrical housings, terminal assemblies and protective covers where moisture or dust ingress needs to be reduced.

Sensors and Instruments

Used in sensor housings, measuring devices and precision assemblies requiring compact fastening and localized sealing.

Automotive Components

Applicable to electronic modules, lamp assemblies, brackets and interior components, subject to assembly validation.

Industrial Equipment

Suitable for machine covers, automation equipment, control cabinets and mechanical housings exposed to dust, oil or moisture.

Outdoor Devices

Can be evaluated for communication equipment, outdoor enclosures and protective housings when the screw material and O-ring are compatible with the environment.

Mechanical Assemblies

Used in covers, brackets and components that require both secure threaded fastening and an additional sealing interface.

Product Application

Black oxide hex socket head sealing screws are designed for fastening covers, housings and precision components where environmental ingress around the screw position needs to be reduced. The cylindrical socket head allows controlled tightening, while the O-ring forms a sealing contact beneath the head.

For reliable performance, the screw, O-ring, mating surface and installation torque should be evaluated as one complete assembly. The O-ring compound and surface treatment should also be selected according to temperature, chemicals, moisture and corrosion exposure.

Why O-Ring Sealing Screws May Fail in Assembly

Incorrect O-Ring Compression

Insufficient compression may leave gaps in the sealing interface, while excessive compression may deform or damage the O-ring.

Incompatible O-Ring Material

An unsuitable elastomer may swell, harden, crack or lose elasticity after exposure to oil, chemicals, heat or outdoor conditions.

Uneven Contact Surface

Burrs, scratches, gaps or uneven mating surfaces can prevent the O-ring from forming uniform contact beneath the screw head.

Incorrect Installation Torque

Low torque may not compress the O-ring sufficiently. Excessive torque may damage the O-ring, thread or mating component.

Improper Head or Groove Geometry

The sealing area must provide enough space to locate and compress the O-ring without cutting it or forcing it out of position.

About Our Factory

30+ Years of Fastener Manufacturing

Yuhuang has specialized in standard and custom fastener manufacturing since 1998, supporting customers from product evaluation through mass production.

20,000㎡ Production Area

Our two manufacturing bases cover approximately 20,000 square meters and support cold heading, thread rolling, machining, inspection and packaging.

In-House Manufacturing Capability

Our production capabilities include cold heading, thread rolling, CNC machining, automatic lathe machining, mold development, washer assembly and custom packaging.

Laboratory Verification

Available inspection capabilities include dimensional inspection, hardness testing, torque testing, tensile testing, pull-out testing, salt spray testing and material analysis.

Quality Management

Our quality management systems include ISO 9001, ISO 14001 and IATF 16949. RoHS and REACH compliance reports can be provided according to material and order requirements.