Heavy Hex Socket Head Cap Screw — GB/T 1228 / ASTM A325 (Series 046) are used primarily for threaded assemblies where the head drive and seating style matter. This page summarizes where they fit, the industries that rely on them, and the practical points to get right when you specify them — to GB/T 1228 / ASTM A325. Stocked across roughly M3 to M36, they cover general to heavy-duty work.
Typical Applications for Heavy Hex Socket Head Cap Screw — GB/T 1228 / ASTM A325 (Series 046)
The most common settings where these are specified:
- General machine building: fastening covers, brackets, motors and sub-assemblies on production equipment.
- Maintenance & repair (MRO): a stocked size for servicing existing plant where the original fastener spec must be matched.
- Fabrication & metalwork: bench and on-site assembly of steel frames, enclosures and weldments.
- Electronics & enclosures: mounting PCBs, panels and lids where the drive style and head height matter.
- Appliances & consumer goods: high-volume assembly with power tools and consistent seating.
How to Specify Heavy Hex Socket Head Cap Screw — GB/T 1228 / ASTM A325 (Series 046) for Your Application
- Size: Match the nominal size to the mating thread or hole. This product spans M3–M36; check the full table below for the exact dimensions of each size.
- Drive & head: Pick the drive (socket, cross, slot) and head style for the tool access and seating surface; a recessed drive resists cam-out under power tools.
- Environment: For damp, coastal or chemical exposure prefer A4/316 stainless or a suitable coating; indoors, plated steel or A2 is usually sufficient.
- Standard: This product is supplied to GB/T 1228 / ASTM A325. Quoting the standard on your order guarantees interchangeable dimensions between suppliers.
Where Heavy Hex Socket Head Cap Screw — GB/T 1228 / ASTM A325 (Series 046) Are Not the Right Choice
Not for high-preload structural joints (use a property-class bolt and nut), and not in thin sheet where a self-drilling or self-tapping type suits better.