A
Anonymous
Apr 22, 2026
Rating: 4/5
Fast Shipping
Product arrived quickly and matches the description. Good selection of sizes available.
Description
GB70 Cylinder Head 8.8 Grade Internal Hex Screw, High-Strength Cup Head, Internal Hex Bolt C4 M5 M6 mm 10 M12
Reviews
Attributes
| Brand | - |
| Category | Industrial Small Parts / Connectors and Fasteners |
| Origin | - |
| Material | Carbon Steel |
| Strength Grade | 8.8 Class |
| Head Style | Socket Cap Head |
| Drive Type | Internal Hexagon |
| Thread Standard | Metric Coarse |
| Surface Finish | Black Oxide |
| Thread Direction | Right Hand |
| Point Type | Flat Point |
| Compliance Standard | GB70 / DIN912 |
| Package Type | Bulk Box |
5 reviews
A
Anonymous
Apr 12, 2026
Rating: 4/5
Good Value
Works well for my project. Threads are clean and consistent. Packaging was secure.
A
Anonymous
Mar 14, 2026
Rating: 5/5
Excellent Quality
These screws are very strong and fit perfectly into my machinery assembly. The black oxide finish looks professional.
A
Anonymous
Feb 14, 2026
Rating: 5/5
Sturdy Fasteners
Happy with the 8.8 grade strength. Used them for automotive repairs and they hold torque well.
A
Anonymous
Feb 07, 2026
Rating: 5/5
Precise Threads
Threads fit perfectly without cross-threading. High strength grade gives me confidence in the build.
5 FAQ
Q: Do you offer M8 size in this listing?
A: Yes, please select the M8 option from the size variation menu before adding to cart.
Q: What is the hardness rating?
A: The 8.8 grade typically corresponds to a hardness range of 22 to 32 HRC.
Q: What Allen key size is needed for M5?
A: For an M5 socket cap screw, you will typically need a 4mm Allen key.
Q: Are these suitable for outdoor use?
A: Black oxide offers limited corrosion resistance. For outdoor use, we recommend applying additional oil or coating.
Q: Is this material stainless steel?
A: No, this product is made of carbon steel with a black oxide finish for general industrial use.
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