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Home / Connectors and Fasteners / Grade 12.9 High-Strength Hex Socket Cap Head Full Thread Screws Cylinder Head Bolts M2 M3 M4 M5 M6 M8-M24

Attributes

Brand -
Category Industrial Small Parts / Connectors and Fasteners
Origin -
Material Alloy Steel
Strength Grade 12.9
Thread Type Metric Coarse
Head Style Socket Cap
Drive Type Hex Socket (Allen)
Surface Finish Black Oxide
Standard Compliance DIN 912 / ISO 4762
Thread Coverage Full Thread
Hardness HRC 39-44
Package Quantity 100 Pieces per Box

5 reviews

A

Anonymous

Apr 08, 2026

Rating: 5/5

Exact Specifications

Measured the diameter and pitch with calipers. Everything matches standard metric specs exactly.

A

Anonymous

Apr 01, 2026

Rating: 5/5

Fast Shipping

Needed these for a quick repair job. Arrived sooner than expected and quality is top notch.

A

Anonymous

Mar 07, 2026

Rating: 4/5

Good Value

Threads are clean and sizing is accurate. Packaging was a bit loose but the bolts themselves are excellent.

A

Anonymous

Feb 25, 2026

Rating: 5/5

Perfect for Machinery

High quality steel and the threads are cut very cleanly. Used these for a CNC machine assembly and they fit perfectly.

A

Anonymous

Feb 21, 2026

Rating: 5/5

Strong and Reliable

Used for automotive engine components. The 12.9 grade provides the tensile strength I needed without stripping.

5 FAQ

Q: Are these suitable for outdoor use without coating?

A: The black oxide finish offers limited corrosion resistance. We recommend additional coating for harsh outdoor environments.

Q: What Allen key size is required for the M6 bolts?

A: For M6 socket cap screws, you will need a 5mm hex key.

Q: Do you offer bulk discounts for large orders?

A: Yes, please contact our sales team directly for pricing on bulk quantities over 10 boxes.

Q: Are these imperial or metric sizes?

A: All sizes listed (M2-M24) are standard metric measurements.

Q: What is the hardness rating for these bolts?

A: These Grade 12.9 bolts typically have a hardness between HRC 39 and 44.

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