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)
Large Bucket 502 Glue, Strong Instant Adhesive, Gold Material 502 Dry Glue for Leather, Metal, Furniture, and Plastic Bonding by Manufacturer

Large Bucket 502 Glue, Strong Instant Adhesive, Gold Material 502 Dry Glue for Leather, Metal, Furniture, and Plastic Bonding by Manufacturer

$1,893.00

Rectangular Plastic Vegetable Planter for Balcony - Durable Home Gardening Pot

Rectangular Plastic Vegetable Planter for Balcony - Durable Home Gardening Pot

$12.90

Chinese Painting Line Drawing Copybook, Gongbi Sketch Template, Large-Scale Tracing Album, Ancient Style Brush Control and Line Practice Book

Chinese Painting Line Drawing Copybook, Gongbi Sketch Template, Large-Scale Tracing Album, Ancient Style Brush Control and Line Practice Book

$7.48

German Continental Tires 225/45R17 Run-Flat, 19-Inch Original Authentic with Full Tread Patterns

German Continental Tires 225/45R17 Run-Flat, 19-Inch Original Authentic with Full Tread Patterns

$380.00

Dynamic Sheet Music Simplified Notation Accompaniment for Electric Wind Instrument Saxophone Hulusi Ocarina Flute Bamboo Flute

Dynamic Sheet Music Simplified Notation Accompaniment for Electric Wind Instrument Saxophone Hulusi Ocarina Flute Bamboo Flute

$10.00

LL Industrial Lint-free Wiping Paper - Oil and Water Absorbent Non-woven Fabric (White/Blue Large Roll)

LL Industrial Lint-free Wiping Paper - Oil and Water Absorbent Non-woven Fabric (White/Blue Large Roll)

$185.82

Continental Quiet Used Car Tires 225/235/245/255/265-35/40/45/50 R17/18/19/20/21/22/23

Continental Quiet Used Car Tires 225/235/245/255/265-35/40/45/50 R17/18/19/20/21/22/23

$284.00

Negotiable Price: Siemens Load Cell 7mh4106-5ec11, Brand New Unused, Contact for Price Negotiation

Negotiable Price: Siemens Load Cell 7mh4106-5ec11, Brand New Unused, Contact for Price Negotiation

$1,332.00

Premium Over-Toilet Storage Organizer, Wall-Mounted Bathroom Shelf, No Drilling Required, Multi-Function Toilet Rack

Premium Over-Toilet Storage Organizer, Wall-Mounted Bathroom Shelf, No Drilling Required, Multi-Function Toilet Rack

$31.76

Model 2000 Large Commercial Vegetable Cutter for Slicing, Dicing, and Cutting Leafy Greens and Kimchi

Model 2000 Large Commercial Vegetable Cutter for Slicing, Dicing, and Cutting Leafy Greens and Kimchi

$11,000.00

Aromatherapy Candle Tool Set - Includes Igniter, Snuffer, Wick Trimmer, Flame Extinguisher Cover, and Rotating Carousel Ornament

Aromatherapy Candle Tool Set - Includes Igniter, Snuffer, Wick Trimmer, Flame Extinguisher Cover, and Rotating Carousel Ornament

$2.55

onlycook 304 Stainless Steel Kitchen Rack with Narrow Edge for Sink, Dishcloth Drainer, and Sponge Basket

onlycook 304 Stainless Steel Kitchen Rack with Narrow Edge for Sink, Dishcloth Drainer, and Sponge Basket

$36.50

7-Piece Square Succulent Pot Set with Trays - Durable Plastic Colorful Root-Control Planters

7-Piece Square Succulent Pot Set with Trays - Durable Plastic Colorful Root-Control Planters

$75.50

Minimalist Japanese Style Kitchen Sponge Brush Dish Soap Drain Rack Air-Dry Cloth Rack Sink Organizer Box

Minimalist Japanese Style Kitchen Sponge Brush Dish Soap Drain Rack Air-Dry Cloth Rack Sink Organizer Box

$21.00

PVC Cable Cover Speed Bump Style Wire Protector for Indoor Cables and Pipes

PVC Cable Cover Speed Bump Style Wire Protector for Indoor Cables and Pipes

$9.10

Spiegel BGF-161 Portable Tire Stone Removal Hook - Multi-function Tool for Cleaning Car Tire Treads

Spiegel BGF-161 Portable Tire Stone Removal Hook - Multi-function Tool for Cleaning Car Tire Treads

$7.84

7A Natural Amethyst Purple Rabbit Hair Loose Beads for Women's DIY Bracelets and Snowflake Necklaces

7A Natural Amethyst Purple Rabbit Hair Loose Beads for Women's DIY Bracelets and Snowflake Necklaces

$3.83

DIY Handmade Soap Silicone Mold, Essential Oil Soap, Creative Gift Soap Base and Aromatherapy Materials, Love Forever Design

DIY Handmade Soap Silicone Mold, Essential Oil Soap, Creative Gift Soap Base and Aromatherapy Materials, Love Forever Design

$12.90

Flameless Aromatherapy Diffuser with Essential Oils, Dried Flowers, and Preserved Flower Decor

Flameless Aromatherapy Diffuser with Essential Oils, Dried Flowers, and Preserved Flower Decor

$13.60

DOUBLECOIN 7.00R16LT-14 (RSS2) All-Steel Radial Truck Tire - Economical and Wear-Resistant

DOUBLECOIN 7.00R16LT-14 (RSS2) All-Steel Radial Truck Tire - Economical and Wear-Resistant

$1,375.00

Tactical Laser Flashlight, Super Bright Rechargeable Mini Portable Light for Outdoor Long-Range Use, Home Multi-Function Zoom

Tactical Laser Flashlight, Super Bright Rechargeable Mini Portable Light for Outdoor Long-Range Use, Home Multi-Function Zoom

$339.22

MOOCAT [Polaroid Style] Hand-drawn Blank Irregular Wood Pulp Fine-grain Paper for Cyanotype, Street Vending, and Art Projects

MOOCAT [Polaroid Style] Hand-drawn Blank Irregular Wood Pulp Fine-grain Paper for Cyanotype, Street Vending, and Art Projects

$11.90

New Pearl Mini Watercolor Solid Set – Portable Travel Sketchbook & Palette Kit for Students, 12 Colors with Magnetic Transparent Case

New Pearl Mini Watercolor Solid Set – Portable Travel Sketchbook & Palette Kit for Students, 12 Colors with Magnetic Transparent Case

$5.78

Natural Cream-Body Green Rutilated Quartz Loose Beads - DIY Handmade Beading Accessories including Spacer Beads and Multi-Gem Bracelet Components

Natural Cream-Body Green Rutilated Quartz Loose Beads - DIY Handmade Beading Accessories including Spacer Beads and Multi-Gem Bracelet Components

$5.25

Fresh Milk Beverage Production Equipment – Small Pasteurization Tank & Fermented Liquid Yogurt Tank

Fresh Milk Beverage Production Equipment – Small Pasteurization Tank & Fermented Liquid Yogurt Tank

$6,580.00

Mold Mirror Polishing Cloth - Removes Material Marks, Available in Red, Yellow, White; Self-Adhesive Velvet for High-Gloss Mirror Finishing

Mold Mirror Polishing Cloth - Removes Material Marks, Available in Red, Yellow, White; Self-Adhesive Velvet for High-Gloss Mirror Finishing

$21.60

High Borosilicate Glass Cup, DIY Scented Candle Transparent Round Cup, Soy Wax Jelly Cup, Wax Molding Empty Container

High Borosilicate Glass Cup, DIY Scented Candle Transparent Round Cup, Soy Wax Jelly Cup, Wax Molding Empty Container

$2.38

Natural Aquamarine Black Flash Loose Beads for DIY Handmade Jewelry, Stringing Beads, and Round Beads

Natural Aquamarine Black Flash Loose Beads for DIY Handmade Jewelry, Stringing Beads, and Round Beads

$0.88

Touchmark Watercolor Sketchbook for Acrylic Markers and Colored Pencils, Mini Portable Pocket Painting Book for Children and Outdoor Sketching

Touchmark Watercolor Sketchbook for Acrylic Markers and Colored Pencils, Mini Portable Pocket Painting Book for Children and Outdoor Sketching

$6.74

Kunzite Loose Beads Donghai Crystal Agate Chalcedony Jade Gemstone Bracelet Pendant Single Bead Cat's Eye Accessories

Kunzite Loose Beads Donghai Crystal Agate Chalcedony Jade Gemstone Bracelet Pendant Single Bead Cat's Eye Accessories

$6.72