S-90324A114 1/4"-20 Shoulder Screws

Key Features & Benefits at a Glance

• Exceptional corrosion resistance with 18-8 stainless steel construction, ideal for harsh industrial environments and extended service life.
• Precise alignment and secure pivoting thanks to the standard shoulder fit, minimizing component wear and ensuring accurate assembly.
li>Superior thread engagement and reliability from the Class 3A fit and left-hand UNC coarse threads, providing a secure fastening solution for reverse-rotation applications.
• High mechanical strength with a tensile strength of 70,000 psi and shear strength of 35,000 psi, ensuring dependable performance under heavy loads.
• Easy installation and removal with a hex socket drive (5/32") and knurled head, offering excellent grip and torque transmission.
• Consistent hardness and durability with a Rockwell B55 rating, resisting deformation and maintaining integrity in demanding applications.
• Compliance with global environmental standards, being RoHS 3 and REACH compliant, making it suitable for regulated industries.

Professional Applications & Engineering Value

This 1/4-20 UNC left-hand thread shoulder screw is engineered to address critical alignment and fastening challenges in industrial machinery. The 18-8 stainless steel material provides excellent resistance to rust and corrosion, which is vital for equipment exposed to moisture or chemicals. The left-hand thread design is specifically beneficial in applications where standard right-hand threads may loosen due to rotational forces, such as in certain types of motors, presses, or conveyor systems. The shoulder acts as a precise locating dowel or pivot point, reducing stress on the threaded section and ensuring accurate component positioning. Combined with a Class 3A thread fit and coarse thread spacing, it offers reliable, vibration-resistant connections. The knurled head and hex socket drive facilitate easy handling and secure tightening, even in confined spaces, making it a versatile choice for assembly lines, automotive jigs, and precision instruments.

Specification Summary & Compliance

This shoulder screw adheres to UNC inch thread standards with a Class 3A thread fit for high precision. The shoulder diameter is 5/16" with a tolerance of -0.004" to -0.002", and the shoulder length is 5/8" with a tolerance of -0.005" to 0.005", ensuring consistent dimensional accuracy. It is manufactured to meet RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) compliance, confirming its suitability for use in environmentally conscious and regulated industrial applications.