Skip to main content
Home / Hardware & Tools / 8.8 Grade Blackened Hex Socket Flange Bolt, Carbon Steel Cylinder Head with Integrated Washer, Anti-Loosening Screw M4 M5 M8 M10

Attributes

Brand -
Category Root / Hardware & Tools
Origin -
Material Carbon Steel
Grade 8.8
Finish Black Oxide (Blackened)
Head Style Hex Socket with Integrated Flange
Drive Type Allen/Hex Key
Thread Standard Metric (ISO)
Available Sizes M4, M5, M8, M10
Feature Integrated Washer for Load Distribution
Application Automotive, Machinery, Structural Assembly
Corrosion Resistance Moderate (Suitable for indoor/dry environments)

6 reviews

A

Anonymous

Mar 29, 2026

Rating: 5/5

Exactly as described

Needed specific flange bolts for a motorcycle modification. These matched the specs perfectly and arrived quickly. Will buy again.

A

Anonymous

Mar 21, 2026

Rating: 4/5

Strong but watch the torque

Very strong 8.8 grade bolts. Just be careful not to over-torque them as the black finish can chip if you go too hard. Overall very satisfied.

A

Anonymous

Mar 20, 2026

Rating: 4/5

Good quality, fast shipping

Solid carbon steel construction. I used the M8 size for a shelving unit. One bolt had a slightly rough thread, but the rest were perfect.

A

Anonymous

Mar 12, 2026

Rating: 5/5

Great value for bulk purchase

Bought a mix of M4 and M5 for my electronics enclosure projects. They hold tight and the flange distributes pressure evenly without cracking the plastic.

A

Anonymous

Mar 10, 2026

Rating: 5/5

Perfect for automotive repairs

These bolts fit perfectly on my engine block. The integrated flange saves time since I don't need separate washers. The black finish looks great too.

A

Anonymous

Mar 02, 2026

Rating: 5/5

Excellent grip and finish

The hex socket is deep and well-machined, so my keys don't strip easily. The black oxide coating provides a nice professional look.

5 FAQ

Q: Does the integrated washer rotate independently?

A: No, the flange is integrated directly into the bolt head and does not rotate independently. This design helps prevent loosening due to vibration compared to a separate washer.

Q: Are these bolts suitable for outdoor use in rainy conditions?

A: While the black oxide finish offers some protection, these are carbon steel and may rust if exposed to constant moisture. We recommend applying additional grease or using stainless steel alternatives for harsh outdoor environments.

Q: Can I use these on aluminum parts without causing galvanic corrosion?

A: Direct contact between carbon steel and aluminum can lead to galvanic corrosion. We suggest using a dielectric grease or an isolation washer between the bolt and the aluminum part to prevent this issue.

Q: What size Allen key do I need for the M10 bolt?

A: For the M10 Hex Socket Flange Bolt, you will typically need an 8mm Allen key. Please check the specific product packaging for confirmation as tolerances can vary slightly by manufacturer.

Q: Do you sell matching nuts for these bolts?

A: These are designed primarily for tapping into threaded holes. However, if you need nuts, standard metric hex nuts corresponding to the bolt size (M4, M5, M8, M10) will fit the threads correctly.

Explore your interests

View More
All Categories
Best Seller (30)
New List (30)
Children's Drawing Board Blackboard Whiteboard Accessories Colorful Whiteboard Markers Chalk Set Magnetic Stickers Toys Letters Numbers Eraser

Children's Drawing Board Blackboard Whiteboard Accessories Colorful Whiteboard Markers Chalk Set Magnetic Stickers Toys Letters Numbers Eraser

$3.00

Automatic Retractable Air Hose Reel - Pneumatic Hose Drum for Auto Repair, Detailing, and Water/Electric Applications

Automatic Retractable Air Hose Reel - Pneumatic Hose Drum for Auto Repair, Detailing, and Water/Electric Applications

$295.00

Sheepskin Rattle Traditional Handmade Baby Safe to Chew Brass Stick Bell Clapper Rattle Intangible Cultural Heritage Leather Newborn

Sheepskin Rattle Traditional Handmade Baby Safe to Chew Brass Stick Bell Clapper Rattle Intangible Cultural Heritage Leather Newborn

$16.00

Glass Reactor with Multi-Function Stirring and High-Temperature Resistance - Double-Layer Glass Reactor from Manufacturer, Customizable

Glass Reactor with Multi-Function Stirring and High-Temperature Resistance - Double-Layer Glass Reactor from Manufacturer, Customizable

$85.00

Charcoal Blending Stump Set for Sketching - Highlight, Shadow, and Detail Tools with Replaceable Sponge Tips for Artists

Charcoal Blending Stump Set for Sketching - Highlight, Shadow, and Detail Tools with Replaceable Sponge Tips for Artists

$4.80

Minimalist Stainless Steel Toothbrush Holder with Drainage - Ins Style Bathroom Organizer for Cosmetics

Minimalist Stainless Steel Toothbrush Holder with Drainage - Ins Style Bathroom Organizer for Cosmetics

$10.40

Qili Automotive Paint Degreasing Cloth – Glue/Dust Removal Paper, Industrial Wiping & Absorbent Paper

Qili Automotive Paint Degreasing Cloth – Glue/Dust Removal Paper, Industrial Wiping & Absorbent Paper

$313.12

Qingzhu Sketch Blending Cotton - Professional Sponge Balls & Paper Stumps for Art Students, Colorful Thick Absorbent Drawing Tools

Qingzhu Sketch Blending Cotton - Professional Sponge Balls & Paper Stumps for Art Students, Colorful Thick Absorbent Drawing Tools

$4.38

Electric Scooter Dashboard Cover for Aima Metaverse PLAY Instrument Panel Screen Protector Waterproof Case

Electric Scooter Dashboard Cover for Aima Metaverse PLAY Instrument Panel Screen Protector Waterproof Case

$13.50

Continental Tire 265/40R22 106V XL FR CSC5 SUV - Compatible with BYD Tang (Removed from Vehicle)

Continental Tire 265/40R22 106V XL FR CSC5 SUV - Compatible with BYD Tang (Removed from Vehicle)

$618.00

Yandi Retainer Storage Case for Kids - Lightweight Portable Box for Orthodontic Aligners and Dentures

Yandi Retainer Storage Case for Kids - Lightweight Portable Box for Orthodontic Aligners and Dentures

$8.42

Zhizhi Manshu Wen Zhengming Small Regular Script Collection of Twelve Ancient Texts: Yueyang Tower Record, Peach Blossom Spring Record, Farewell to Dongyang Ma Sheng Xu

Zhizhi Manshu Wen Zhengming Small Regular Script Collection of Twelve Ancient Texts: Yueyang Tower Record, Peach Blossom Spring Record, Farewell to Dongyang Ma Sheng Xu

$68.00

Factory Direct Rubber Molding Tools - Custom Production & Processing

Factory Direct Rubber Molding Tools - Custom Production & Processing

$2,280.00

Catalytic Combustion Waste Gas Treatment Equipment - RCO Activated Carbon Adsorption and Desorption Integrated Machine for Industrial Exhaust Processing

Catalytic Combustion Waste Gas Treatment Equipment - RCO Activated Carbon Adsorption and Desorption Integrated Machine for Industrial Exhaust Processing

$26,000.00

ASY Gravure Printing Machine for Plastic Film, 6-Color Flexographic Printer for Shopping Bags

ASY Gravure Printing Machine for Plastic Film, 6-Color Flexographic Printer for Shopping Bags

$86,400.00

Coil Refractory Cement for Medium-Frequency Furnace Repair - Fine High-Temperature Bonding Agent for Copper Coils (White/Red)

Coil Refractory Cement for Medium-Frequency Furnace Repair - Fine High-Temperature Bonding Agent for Copper Coils (White/Red)

$7,800.00

Over-Toilet Storage Rack - No-Drill Bathroom Organizer Shelf for Restrooms and Washrooms, Space-Saving Storage Solution

Over-Toilet Storage Rack - No-Drill Bathroom Organizer Shelf for Restrooms and Washrooms, Space-Saving Storage Solution

$8.90

NIU NXT Instrument Cover for FXT/FX Electric Scooters – Waterproof Protective Case and Modification Accessory

NIU NXT Instrument Cover for FXT/FX Electric Scooters – Waterproof Protective Case and Modification Accessory

$6.50

Anlin FK1 Cheyenne Tattoo Pen Silent Model All-in-One for Lining and Shading

Anlin FK1 Cheyenne Tattoo Pen Silent Model All-in-One for Lining and Shading

$221.25

[Osstem Dental Implants] Imported Dental Crowns and Bridges by Aizhier Oral Care for Partial Tooth Loss

[Osstem Dental Implants] Imported Dental Crowns and Bridges by Aizhier Oral Care for Partial Tooth Loss

$230.00

Heavy-Duty Multi-Layer Warehouse Shelving Unit for Storage, Retail, and Home Use

Heavy-Duty Multi-Layer Warehouse Shelving Unit for Storage, Retail, and Home Use

$252.00

Rattle Car Teether Wooden Bead Educational Soothing Teething Set Baby Photo Prop

Rattle Car Teether Wooden Bead Educational Soothing Teething Set Baby Photo Prop

$15.00

Roast Duck and BBQ Warmer Cabinet - Constant Temperature Heating Display Case for Crispy Pork Belly and Hanging Ducks

Roast Duck and BBQ Warmer Cabinet - Constant Temperature Heating Display Case for Crispy Pork Belly and Hanging Ducks

$710.00

Traditional Handmade Baby Rattle with Chewable Sheepskin for Newborns

Traditional Handmade Baby Rattle with Chewable Sheepskin for Newborns

$12.50

5pcs Lily tubular length 7cm fish tank aquarium  glass

5pcs Lily tubular length 7cm fish tank aquarium glass

$9.90

Data Cable Interface Safety Case for iPhone, Apple, and Android Charging Cables - Child and Pet Proof

Data Cable Interface Safety Case for iPhone, Apple, and Android Charging Cables - Child and Pet Proof

$16.80

Commercial Roast Duck Warmer Cabinet Constant Temperature Food Heater Display Counter for Cooked Meat

Commercial Roast Duck Warmer Cabinet Constant Temperature Food Heater Display Counter for Cooked Meat

$1,494.00

Over-Toilet Storage Rack - Multi-Layer Bathroom Organizer with No-Drill Installation for Tank and Supplies

Over-Toilet Storage Rack - Multi-Layer Bathroom Organizer with No-Drill Installation for Tank and Supplies

$17.92

Natural 7A White Azeztulite Loose Beads for DIY Handmade Bracelets, Spacer Beads, Multi-Gem Jewelry Accessories

Natural 7A White Azeztulite Loose Beads for DIY Handmade Bracelets, Spacer Beads, Multi-Gem Jewelry Accessories

$2.07

Hanyue Cordura N66 Rafting Bag Outdoor Swimming Trekking Clothes Storage Ultra-Light Waterproof Dry Bag

Hanyue Cordura N66 Rafting Bag Outdoor Swimming Trekking Clothes Storage Ultra-Light Waterproof Dry Bag

$35.70