A
Anonymous
Mar 26, 2026
Rating: 4/5
Good value
Quality is good for the price. One bolt had a slightly burred head but still usable.
Description
Grade 12.9 High-Strength Hex Socket Screws Extra-Long Full Thread Button Head Bolts M3 M5 M6 M8 M10 M24 M30
Reviews
Attributes
| Brand | - |
| Category | Industrial Small Parts / Connectors and Fasteners |
| Origin | - |
| Material | Alloy Steel |
| Strength Grade | 12.9 |
| Thread Style | Full Thread |
| Head Type | Hex Socket Cap |
| Drive Type | Internal Hex |
| Surface Finish | Black Oxide |
| Hardness | HRC 39-44 |
| Tensile Strength | 1220 MPa Min |
| Available Sizes | M3, M5, M6, M8, M10, M24, M30 |
| Package Quantity | 10 Pieces per Pack |
5 reviews
A
Anonymous
Mar 17, 2026
Rating: 5/5
Perfect fit
Threads were clean and matched my nuts perfectly. Will order again.
A
Anonymous
Feb 28, 2026
Rating: 5/5
Excellent strength
These bolts held up under significant stress in my automotive project. True 12.9 grade.
A
Anonymous
Feb 22, 2026
Rating: 5/5
Professional quality
Use these in my shop daily. No stripping on the hex socket even with high torque.
A
Anonymous
Jan 28, 2026
Rating: 5/5
Hard to find sizes
Finally found M30 extra long bolts. Shipping was fast and packaging protected the threads.
5 FAQ
Q: Is the thread pitch standard coarse?
A: Yes, unless specified otherwise, these come with standard coarse metric thread pitch.
Q: Do you sell matching nuts?
A: Yes, please search for Grade 12 or Grade 10 nuts compatible with metric hex bolts in our store.
Q: Are these suitable for outdoor use?
A: They have black oxide coating which offers limited protection. For outdoor use, we recommend applying grease or using stainless steel.
Q: What hex key size is needed for M8?
A: Typically an 6mm hex key is required for M8 socket cap screws.
Q: Can these be welded?
A: Welding high tensile steel like Grade 12.9 is not recommended as it affects the heat treatment and strength.
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