Skip to main content
Home / Screws / Grade 12.9 High-Strength Socket Set Screw Cup Point Machine Screw Set Screw Kit M3 M4 M5 M6 M8

Attributes

Brand -
Category Standard Parts, Components & Industrial Consumables / Screws
Origin -
Material Grade Alloy Steel Grade 12.9
Head Style Socket Cup Point
Drive Type Hex Socket (Allen)
Included Sizes M3, M4, M5, M6, M8
Surface Finish Black Oxide Coated
Thread Standard ISO Metric Coarse
Hardness Rating HRC 39-44
Tensile Strength 1220 MPa Minimum
Package Contents Assorted Kit with Storage Box
Application Heavy Duty Machinery & Automotive

6 reviews

A

Anonymous

Mar 25, 2026

Rating: 4/5

Very hard, be careful not to overtighten

Grade 12.9 is no joke; these are extremely hard. Make sure you use a calibrated torque wrench because it is easy to snap the head off if you apply too much force. Otherwise, great product.

A

Anonymous

Mar 23, 2026

Rating: 5/5

Reliable industrial grade fasteners

I order these regularly for our production line. Consistency is key, and this batch matched our specifications exactly. No defects found in the hundreds of screws we inspected.

A

Anonymous

Mar 18, 2026

Rating: 4/5

Good value for money

Solid set of screws for the price. The storage case is a bit flimsy, but the screws themselves are top-notch. Would recommend for any serious DIYer or mechanic.

A

Anonymous

Mar 11, 2026

Rating: 5/5

Excellent quality for heavy machinery

These screws are incredibly strong. I used the M6 and M8 sizes to secure components on a lathe, and they held up perfectly under high vibration. The hex sockets are precise and didn't strip.

A

Anonymous

Mar 02, 2026

Rating: 5/5

Perfect fit for automotive projects

Used the M5 screws for a custom intake manifold setup. The cup point digs in well to prevent slipping. The threads were clean and rolled smoothly into the tapped holes.

A

Anonymous

Mar 01, 2026

Rating: 5/5

Great assortment kit

Having all these common metric sizes in one box is a lifesaver for my workshop. The black oxide finish looks professional and seems to offer decent corrosion resistance for indoor use.

5 FAQ

Q: What is the return policy if the sizes don't match my needs?

A: We offer a 30-day return policy for unused items in their original packaging. Please contact our customer service team to initiate a return request.

Q: Does this kit include a thread locking compound?

A: No, this kit includes only the socket set screws and the storage box. Thread locking compound is sold separately.

Q: Are these screws suitable for outdoor applications?

A: While the black oxide finish offers some protection, Grade 12.9 steel is susceptible to rust in wet environments. For outdoor use, we recommend applying a thread-locking fluid with corrosion inhibitors or using stainless steel alternatives if strength requirements allow.

Q: What size Allen key do I need for the M6 screw?

A: For standard ISO metric socket set screws, an M6 screw typically requires a 5mm hex key. However, please verify with a caliper as tolerances can vary slightly by manufacturer.

Q: Can these be used in aluminum threads?

A: Yes, but caution is advised. Because Grade 12.9 is much harder than aluminum, there is a risk of galling or stripping the aluminum threads if over-torqued. Use proper torque settings and consider using a thread insert for high-load applications.

Explore your interests

View More
All Categories
Best Seller (30)
New List (30)
[Chip 3.0 Upgraded Model] Senzhou TDS Water Quality Tester for Tap and Drinking Water Health Monitoring

[Chip 3.0 Upgraded Model] Senzhou TDS Water Quality Tester for Tap and Drinking Water Health Monitoring

$22.90

Here and Now Pocket Calligraphy Copybook: Wen Zhengming Small Regular Script for Adult Beginners

Here and Now Pocket Calligraphy Copybook: Wen Zhengming Small Regular Script for Adult Beginners

$18.00

Southern Red Agate Loose Beads for DIY Crystal Jewelry Making, Round Bead Accessories and Materials

Southern Red Agate Loose Beads for DIY Crystal Jewelry Making, Round Bead Accessories and Materials

$1.10

3-Tier, 4-Tier, 5-Tier Double-Layer Drainage Rack, Water Bucket Stand, Floor-Standing Thickened Rack

3-Tier, 4-Tier, 5-Tier Double-Layer Drainage Rack, Water Bucket Stand, Floor-Standing Thickened Rack

$276.32

Multi-Layer Over-Toilet Storage Rack for Bathroom, Drill-Free Floor Stand for Washing Machine and Balcony Organization

Multi-Layer Over-Toilet Storage Rack for Bathroom, Drill-Free Floor Stand for Washing Machine and Balcony Organization

$46.96

Thickened Industrial Scouring Pad Emery Stainless Steel Abrasive Cloth Pot Scrubber Rust Removal and Polishing Wheel

Thickened Industrial Scouring Pad Emery Stainless Steel Abrasive Cloth Pot Scrubber Rust Removal and Polishing Wheel

$7.28

Wall-Mounted Bathroom Toilet Paper Holder and Tissue Dispenser Rack

Wall-Mounted Bathroom Toilet Paper Holder and Tissue Dispenser Rack

$49.00

Arches French Watercolor Paper 300g/640g/850g, Cold/Hot Press, 100% Cotton, Deckled Edge, 2K/4K/8K

Arches French Watercolor Paper 300g/640g/850g, Cold/Hot Press, 100% Cotton, Deckled Edge, 2K/4K/8K

$29.60

Wen Xin Tang Yan Zhenqing Duobao Pagoda Stele Calligraphy Copybook, Tang Regular Script, Adult Beginner Calligraphy Practice Cards

Wen Xin Tang Yan Zhenqing Duobao Pagoda Stele Calligraphy Copybook, Tang Regular Script, Adult Beginner Calligraphy Practice Cards

$49.30

[Shenzhen Best Seller] Premium Wearable Negative Ion Air Purifier - Neck-Hanging Portable Electronic Mask

[Shenzhen Best Seller] Premium Wearable Negative Ion Air Purifier - Neck-Hanging Portable Electronic Mask

$298.00

Teruisi Electric Fruit and Vegetable Slicer, Multifunctional Chopper for Cafeterias and Hotels, Cutter for Green Onions, Chili Peppers, Radishes, and Ginger

Teruisi Electric Fruit and Vegetable Slicer, Multifunctional Chopper for Cafeterias and Hotels, Cutter for Green Onions, Chili Peppers, Radishes, and Ginger

$3,798.00

Waterproof Phone Pouch for Diving, Swimming, Rafting, and Hot Springs, Sealed Underwater Storage Bag with Waist Strap

Waterproof Phone Pouch for Diving, Swimming, Rafting, and Hot Springs, Sealed Underwater Storage Bag with Waist Strap

$12.90

Premium Thick Cardstock Lin Zexu Representative Small Regular Script Infinite Life Sutra Close-Up Copying Calligraphy Copybook Regular Script for Beginners

Premium Thick Cardstock Lin Zexu Representative Small Regular Script Infinite Life Sutra Close-Up Copying Calligraphy Copybook Regular Script for Beginners

$39.80

Zunjue Ticket-style 100% Cotton Watercolor Paper 300g Cold Press for Artists with Deckled Edges

Zunjue Ticket-style 100% Cotton Watercolor Paper 300g Cold Press for Artists with Deckled Edges

$10.20

Kids' 3D Printing Pen – 3D Stereoscopic Drawing Toy for Girls, Perfect Birthday Gift

Kids' 3D Printing Pen – 3D Stereoscopic Drawing Toy for Girls, Perfect Birthday Gift

$104.66

Mifaner Handmade Watercolor Sketchbook – Oil Painting Series Canvas Journal, Travel-Friendly Mini Notebook for Acrylic Markers

Mifaner Handmade Watercolor Sketchbook – Oil Painting Series Canvas Journal, Travel-Friendly Mini Notebook for Acrylic Markers

$16.90

(Sasha Exclusive) Fat Small Card

(Sasha Exclusive) Fat Small Card

$1,399.00

Silicone Faucet Side Drain Mat, Foldable Splash-Proof Pad for Kitchen Sink and Bathroom Washbasin

Silicone Faucet Side Drain Mat, Foldable Splash-Proof Pad for Kitchen Sink and Bathroom Washbasin

$4.93

Breathable Portable Invisible Aligner Case with Lanyard – Durable Hygienic Storage for Orthodontic Retainers and Dentures

Breathable Portable Invisible Aligner Case with Lanyard – Durable Hygienic Storage for Orthodontic Retainers and Dentures

$18.10

Snail-Specific Slug & Snail Killer Scatter-Type Anti-Pest Granules for Vegetable Gardens Slugs Apple Snails Fruit & Vegetable Fields

Snail-Specific Slug & Snail Killer Scatter-Type Anti-Pest Granules for Vegetable Gardens Slugs Apple Snails Fruit & Vegetable Fields

$10.00

Industrial Scouring Pad for Woodworking, Paint Sanding, and Polishing - Ultra-Fine Hand-Tear Sheets

Industrial Scouring Pad for Woodworking, Paint Sanding, and Polishing - Ultra-Fine Hand-Tear Sheets

$135.70

Custom G80 Manganese Steel Lifting Chain - High-Strength Alloy Chain Rigging for Hoisting and Cranes

Custom G80 Manganese Steel Lifting Chain - High-Strength Alloy Chain Rigging for Hoisting and Cranes

$655.00

High-Concentration Oxygen Generator for Aquaculture with High-Pressure Outlet, Ceramic Nano Disc, and Oxygen Dissolution Cone

High-Concentration Oxygen Generator for Aquaculture with High-Pressure Outlet, Ceramic Nano Disc, and Oxygen Dissolution Cone

$50.00

Paint Brush Rinser – Art Supply Cleaning Cup for Brushes, Palettes, and Pigment Washing

Paint Brush Rinser – Art Supply Cleaning Cup for Brushes, Palettes, and Pigment Washing

$21.80

Heidelberg Printing Press Paper Pressure Wheel Screen Printing Roller Felt Wheel Guanghua Beiren Paper Feed Wheel Laminating Machine Brush Wheel

Heidelberg Printing Press Paper Pressure Wheel Screen Printing Roller Felt Wheel Guanghua Beiren Paper Feed Wheel Laminating Machine Brush Wheel

$6.00

Baofeifan Bubble Squeeze Painting Kit for Kids - Foaming Textured Paper, Wood Pulp Cotton DIY 3D Art with Markers

Baofeifan Bubble Squeeze Painting Kit for Kids - Foaming Textured Paper, Wood Pulp Cotton DIY 3D Art with Markers

$10.00

Westwood Portable Retainer Case for Elderly Dentures and Children's Orthodontic Correctors, Storage Box

Westwood Portable Retainer Case for Elderly Dentures and Children's Orthodontic Correctors, Storage Box

$14.20

PELICAN 1510 Protective Safety Case with Trolley - Waterproof Travel Box for Outdoor Photography Gear

PELICAN 1510 Protective Safety Case with Trolley - Waterproof Travel Box for Outdoor Photography Gear

$1,360.00

Haisen [Exclusive Purchase Link] Livestream Link for New Arrivals and Clearance - Incense Sticks, Coil Incense, Agarwood, Sandalwood, Powder, Burners

Haisen [Exclusive Purchase Link] Livestream Link for New Arrivals and Clearance - Incense Sticks, Coil Incense, Agarwood, Sandalwood, Powder, Burners

$13.80

Ultralight Silicone-Coated Waterproof Dry Bag for Outdoor River Trekking, Rafting, Swimming, Beach Use – Wet/Dry Separation Storage for Swimwear and Towels

Ultralight Silicone-Coated Waterproof Dry Bag for Outdoor River Trekking, Rafting, Swimming, Beach Use – Wet/Dry Separation Storage for Swimwear and Towels

$38.20