Hex Nuts

• ANSI
• RoHS
• ASME
• DIN
• FDA
• ISO
• SAE
• UL

Hexagonal-shaped nuts are easier to turn than other types of fasteners as they have six parallels and require less turning distance / radius. They only need one-sixth or 30 degrees of turning each time to reach the next flat parallel.

If you are mating NPSM threads with NPTF or NPT threads, make use of sealant or pipe tape to assure liquid and air-tight sealing.

The tool needed to tighten a fastener depends on its drive type. Deeper grooves and more points of contact on internal drive designs provide a sturdy grip and need less power to tighten. On the other hand, even lesser force is required to tighten external drive types as they may be secured using a wrench or socket.

• SAE: They are used for Imperial fasteners. The higher the grade, the stronger the fastener. Fasteners with the same grade are designed to be used together. They include SAE Grade 2, 5 and 8 fasteners for light to heavy fastening / stress applications.
• ISO: Metric fasteners have classifications according to ISO standards. The higher the class, the stronger the fastener. Fasteners with the same first digit are used together. They are available in ISO Class 4, 5, 6, 8, 10 and 12 for light duty fastening or high-stress applications.
• ASTM: ASTM grades fasteners based on strength. They are available in ASTM Grade 2H, 7, 8, 8M and DH for high strength, stress, pressure & temperature applications. ASTM Grade C units are medium-strength steel nuts.
• ASME: They are available in Grade F & G for medium or high-stress applications.