Skip to main content
Home / Connectors and Fasteners / Grade 12.9 High-Strength Countersunk Hex Socket Screws Flat Head Hex Bolts M3 M4 M5 M6 M8 M10 M20

Attributes

Brand -
Category Industrial Small Parts / Connectors and Fasteners
Origin -
Material Alloy Steel
Strength Grade 12.9
Head Style Countersunk Flat Head
Drive Type Hex Socket (Allen)
Thread Type Metric Coarse
Surface Finish Black Oxide
Standard DIN 7991
Available Sizes M3, M4, M5, M6, M8, M10, M20
Hardness 39-44 HRC
Package Quantity Varies by Selection

5 reviews

A

Anonymous

Apr 17, 2026

Rating: 5/5

Excellent Strength

Used these for high tension assembly on my CNC machine. No stripping and they held torque perfectly.

A

Anonymous

Apr 16, 2026

Rating: 5/5

High Quality

True 12.9 grade, tested with hardness kit. Very satisfied with the material quality.

A

Anonymous

Apr 02, 2026

Rating: 5/5

Fast Delivery

Arrived next day. Exactly what I needed for my automotive project. Will order again.

A

Anonymous

Mar 23, 2026

Rating: 5/5

Perfect Fit

Threads are clean and precise. M6 size fit exactly as expected without any cross-threading issues.

A

Anonymous

Mar 21, 2026

Rating: 4/5

Good Value

Great bolts for the price. Packaging could be better to prevent scratching during shipping.

5 FAQ

Q: Is this stainless steel?

A: No, this is alloy steel designed for high strength applications.

Q: Are these plated for rust resistance?

A: Yes, they feature a black oxide finish for mild corrosion protection.

Q: What key size is needed for M5?

A: You will typically need a 4mm Allen key for M5 screws.

Q: Do you sell M12 size?

A: Currently we stock up to M10 and M20. M12 is not available at this time.

Q: Is there a bulk discount available?

A: Yes, please contact support for orders exceeding 500 units.

Explore your interests

View More
All Categories
Best Seller (30)
New List (30)
CANDLE.LAB | Silicone Border Mat for DIY Scented Candles and Soap Making Tray Mold

CANDLE.LAB | Silicone Border Mat for DIY Scented Candles and Soap Making Tray Mold

$32.00

Shiji Runde Coal Shed Mine Dust Removal Explosion-Proof Anti-Freezing Fog Cannon Port Dust Suppression 80m Ultra-Fine Industrial Fog Machine

Shiji Runde Coal Shed Mine Dust Removal Explosion-Proof Anti-Freezing Fog Cannon Port Dust Suppression 80m Ultra-Fine Industrial Fog Machine

$4,180.00

Mobile Retractable Spray Booth for Furniture - Foldable Track-Mounted Painting Room

Mobile Retractable Spray Booth for Furniture - Foldable Track-Mounted Painting Room

$6,240.00

Long Handle Bristle Paint Brush - Hog Hair Brush for Oil Painting, Acrylic Wall Art, and Children's Drawing

Long Handle Bristle Paint Brush - Hog Hair Brush for Oil Painting, Acrylic Wall Art, and Children's Drawing

$1.80

Electrostatic Powder Coating Equipment and Electronic Powder Dispenser Supply

Electrostatic Powder Coating Equipment and Electronic Powder Dispenser Supply

$17,250.00

DIY Toast-Shaped Silicone Mold for Handmade Soap - Square Soap Making Mold

DIY Toast-Shaped Silicone Mold for Handmade Soap - Square Soap Making Mold

$105.00

Kindergarten Sponge Stamp Set – Mushroom-Head Circular Printing Tools for Kids' DIY Art and Painting Kits

Kindergarten Sponge Stamp Set – Mushroom-Head Circular Printing Tools for Kids' DIY Art and Painting Kits

$3.50

Heavy-Duty Lifting Chain Set – Manganese Steel Chains with Hooks, Rings, and Hoist Accessories

Heavy-Duty Lifting Chain Set – Manganese Steel Chains with Hooks, Rings, and Hoist Accessories

$198.00

Car Tire Stone Removal Tool, Multi-Function Groove Hook for Portable Tire Picking and Cleaning

Car Tire Stone Removal Tool, Multi-Function Groove Hook for Portable Tire Picking and Cleaning

$11.50

m Dogs Strap Auto Retractable Dual Dog Leash With

m Dogs Strap Auto Retractable Dual Dog Leash With

$199.92

Traditional Wooden Sheepskin Rattle Toy – Safe for Teething Newborns, Handcrafted Baby Bell Shaker

Traditional Wooden Sheepskin Rattle Toy – Safe for Teething Newborns, Handcrafted Baby Bell Shaker

$17.80

Soilless Cultivation Equipment Plant Factory Display Rooftop Hydroponic Pipe System for Leafy Vegetables and Fruits, Type A Planting Rack

Soilless Cultivation Equipment Plant Factory Display Rooftop Hydroponic Pipe System for Leafy Vegetables and Fruits, Type A Planting Rack

$2,620.16

Premium Ceramic Tea Canister and Gift Box Set - Empty Packaging for Black Tea, Pu'er, White Tea, and Biluochun

Premium Ceramic Tea Canister and Gift Box Set - Empty Packaging for Black Tea, Pu'er, White Tea, and Biluochun

$121.00

Posture-Correcting Hole-Grip Pencils for Grade 1 - Triangular Barrel, Break-Resistant, Non-Toxic HB for Daily Writing and 2B for Exams

Posture-Correcting Hole-Grip Pencils for Grade 1 - Triangular Barrel, Break-Resistant, Non-Toxic HB for Daily Writing and 2B for Exams

$3.02

Genuine OEM AC Blower Motor Heater Fan for Buick Excelle GT, Cavalier, and Monza

Genuine OEM AC Blower Motor Heater Fan for Buick Excelle GT, Cavalier, and Monza

$255.00

TA1 TA2 Titanium Capillary Tubes - Small Diameter Titanium Pipes - GR5 Titanium Alloy Tubes

TA1 TA2 Titanium Capillary Tubes - Small Diameter Titanium Pipes - GR5 Titanium Alloy Tubes

$240.00

Industrial Spray Painting Wipe Cloth Auto Bake Finish Film Application Degreasing Cloth Non-Woven Absorbent Paper Lint-Free Paper Electrostatic Dust Removal Paper

Industrial Spray Painting Wipe Cloth Auto Bake Finish Film Application Degreasing Cloth Non-Woven Absorbent Paper Lint-Free Paper Electrostatic Dust Removal Paper

$75.66

US Standard Buttress Thread Inserts 22ER 16ER 11NR 16 10 12 8ABUT Internal 7 External 45 Degree

US Standard Buttress Thread Inserts 22ER 16ER 11NR 16 10 12 8ABUT Internal 7 External 45 Degree

$43.20

Coating Workshop Cleaning Rags GAE Industry White Scrap Cloth Nylon Machine Cloth Blocks Industrial Glue Removal Furniture Cleaning

Coating Workshop Cleaning Rags GAE Industry White Scrap Cloth Nylon Machine Cloth Blocks Industrial Glue Removal Furniture Cleaning

$96.31

Natural 8A Yellow Tiger Eye Loose Beads - Round Cat's Eye Bracelet for DIY Jewelry Making

Natural 8A Yellow Tiger Eye Loose Beads - Round Cat's Eye Bracelet for DIY Jewelry Making

$17.28

Paper Blending Stumps Art Set for Highlighting, Sketching, and Smudging - Professional Drawing Tools for Artists and Beginners with Rice Paper Details and Oil Pastels

Paper Blending Stumps Art Set for Highlighting, Sketching, and Smudging - Professional Drawing Tools for Artists and Beginners with Rice Paper Details and Oil Pastels

$6.80

Rubber Speed Bump 1000x350x40mm Herringbone Pattern

Rubber Speed Bump 1000x350x40mm Herringbone Pattern

$96.89

Xian Kan Yun Shu [Cloud Lark] Elegant Brush Washer, Hand-Painted Orchid and Sparrow Design under Glaze, Ceramic Water Pot

Xian Kan Yun Shu [Cloud Lark] Elegant Brush Washer, Hand-Painted Orchid and Sparrow Design under Glaze, Ceramic Water Pot

$21.20

Cable Organizer Hook-and-Loop Straps for Data/Charging Cables, Laptop Power, Mouse, Headphones, and Under-Desk Network Wiring

Cable Organizer Hook-and-Loop Straps for Data/Charging Cables, Laptop Power, Mouse, Headphones, and Under-Desk Network Wiring

$7.48

Power Strip Organizer Box, Desktop Socket Concealment Case for Charging Cables and Power Cords, Hidden Storage Shelf

Power Strip Organizer Box, Desktop Socket Concealment Case for Charging Cables and Power Cords, Hidden Storage Shelf

$21.93

Automatic Dairy Beverage Filling Machine - Fully Automatic Equipment for Milk, Soy Milk, and Drink Bottling

Automatic Dairy Beverage Filling Machine - Fully Automatic Equipment for Milk, Soy Milk, and Drink Bottling

$1,316.00

Compact Invisible Retainer Case - Leak-Proof Sealed Storage Box for Children's Orthodontic Aligners

Compact Invisible Retainer Case - Leak-Proof Sealed Storage Box for Children's Orthodontic Aligners

$12.50

07521 Scouring Pad Roll for Woodworking, Furniture, Paint Sanding, Metal Deburring, and Brushed Finish - Purple 600 Grit

07521 Scouring Pad Roll for Woodworking, Furniture, Paint Sanding, Metal Deburring, and Brushed Finish - Purple 600 Grit

$81.00

Shiya Insulated Display Cabinet, Constant Temperature Warmer for Commercial Use, Crispy Pork Belly, Roast Duck, Roast Chicken, and Cooked Food

Shiya Insulated Display Cabinet, Constant Temperature Warmer for Commercial Use, Crispy Pork Belly, Roast Duck, Roast Chicken, and Cooked Food

$388.00

Wooden Soap Trimmer with Drawer, Soap Planer and Edge Shaper, Free Shipping

Wooden Soap Trimmer with Drawer, Soap Planer and Edge Shaper, Free Shipping

$32.00