Black Hex Head Bolt With Integrated Flat Washer Assembly

Core Features

Integrated Flat Washer – A flat washer is permanently attached to the bolt beneath the head, providing a bearing surface that distributes clamping load across the workpiece. The attached washer prevents loss or misplacement during handling and assembly.

Hexagon Head Configuration – The bolt features a standard hexagon head that accepts conventional sockets or wrenches. The hexagon profile supports torque application for tightening and removal.

Black Surface Treatment – The black finish provides a corrosion-resistant barrier layer with a uniform appearance. The finish is applied through an oxidation or coating process to provide defined corrosion resistance properties.

One-Piece Assembly – The washer is permanently attached to the bolt, eliminating the need for separate washer handling during assembly. The integrated design reduces part count and assembly steps.

Product Characteristics

The bolt is manufactured with a hexagon head, a threaded shank, and an integrated flat washer positioned beneath the head. The washer is dimensioned with an outer diameter that extends beyond the bolt head bearing surface, providing increased load distribution. The washer is captured on the bolt shank by a crimping or retaining feature that prevents separation during handling and shipping.

Thread dimensions and tolerances follow standard metric profiles. Performance grades 8.8 and 10.9 provide defined tensile strength and yield strength specifications. The surface treatment is applied through an oxidation process, producing a consistent black finish with defined corrosion resistance properties.

Application Scenarios

Automotive Assembly – Used in vehicle body panels, chassis components, and structural assemblies where load distribution across thin panels is required. The integrated washer protects the workpiece surface during tightening.

Sheet Metal Fabrication – Applied where load-bearing threads are required in sheet metal and where the washer provides load distribution and surface protection. The attached washer prevents damage to the panel during assembly.

Equipment and Machinery Manufacturing – Used in equipment frames and machinery where the integrated washer provides a bearing surface and prevents rotation of the washer during tightening.

General Industrial Assembly – Employed in structural and mechanical applications where the washer provides load distribution and the black finish provides corrosion resistance.

Customization Options

Specifications and configurations can be adjusted based on application requirements. Thread sizes are available in metric configurations M3 to M24. Lengths are customizable according to application geometry. Performance grades 8.8 and 10.9 are available based on strength requirements. Surface treatments are selectable according to environmental exposure conditions, including black oxide, zinc plating, and other finishes.

Frequently Asked Questions

Q: What is the advantage of the integrated washer design?
A: The integrated washer is permanently attached to the bolt, preventing loss or misplacement of the washer during handling and assembly. This reduces part count and assembly steps, and ensures the washer is properly positioned when the bolt is installed.

Q: What is the purpose of the black surface treatment?
A: The black finish provides corrosion resistance and a uniform appearance. The treatment is applied through an oxidation or coating process to provide defined corrosion resistance properties.

Q: What are the available performance grades?
A: Performance grades 8.8 and 10.9 are available, providing defined tensile strength and yield strength specifications for medium to heavy-duty applications.

Q: Are these bolts removable after installation?
A: Yes. The bolt is designed for installation and removal using standard sockets or wrenches. The integrated washer remains attached to the bolt during removal.

Q: What is the typical corrosion resistance of the black finish?
A: Corrosion resistance of black oxide finishes is determined by the specific coating specification and post-treatment sealing. The finish provides moderate corrosion protection for indoor and mild exposure applications.

Installation Considerations

The bolt should be installed with the integrated washer seated against the workpiece surface. The washer should be positioned to provide load distribution and surface protection. Torque should be applied according to specified tightening procedures for the thread size and performance grade. The hexagon head supports torque application using standard sockets or wrenches. Thread condition should be inspected before installation; damaged threads may affect torque readings and assembly integrity. For plated or coated bolts, coating thickness should be within specified tolerances to maintain thread fit. The integrated washer remains in position during tightening, eliminating the need for separate washer placement.