S-90519A872 1/2"-20 ASTM A108 Hex Nuts

Key Features & Benefits at a Glance

• Enhanced corrosion resistance with black-oxide steel coating, ideal for humid or demanding industrial environments
• Secure left-hand thread engagement prevents loosening in counter-rotational applications, ensuring operational safety
• Space-saving thin profile design (5/16" height) allows installation in tight or restricted areas without compromising strength
• Precise Class 2B thread fit delivers smooth assembly and reliable vibration resistance with standard UNF fine-threaded bolts
• Durable Grade 2 steel construction provides dependable tensile strength for general-purpose and light-duty fastening needs
• Wide 3/4" hex width offers superior tool grip for efficient installation and removal using standard wrenches
• Full regulatory compliance with RoHS 3 and REACH standards, meeting international environmental and safety requirements

Professional Applications & Engineering Value

This left-hand thread hex nut is engineered to address critical challenges in machinery and equipment where reverse rotation is prevalent. The black-oxide finish on Grade 2 steel significantly enhances corrosion resistance, reducing maintenance frequency in industrial settings exposed to moisture or chemicals. Its thin profile (5/16" height) is particularly valuable in compact assemblies—such as automotive components, conveyor systems, or rotating shafts—where space constraints demand low-profile fasteners without sacrificing performance. The 1/2"-20 UNF fine threading with Class 2B fit ensures precise, vibration-resistant connections, minimizing the risk of unintended loosening in high-stress applications. Manufactured to ASTM A108 specifications, this nut delivers consistent quality and reliability, making it a trusted choice for maintenance, repair, and OEM operations requiring left-hand threaded solutions.

Specification Summary & Compliance

This nut features a 1/2"-20 UNF left-hand fine thread with Class 2B thread fit for accurate engagement and assembly ease. It adheres to ASTM A108 material standards and is compliant with RoHS 3 (2015/863/EU) under exemption 6(a) for lead as a steel alloying element, alongside full REACH (EC 1907/2006) compliance. Dimensions include a 3/4" width and 5/16" height, with an external hex drive for standard tool compatibility.