STS Industrial - Bolts & Screws

 

SOCKET HEAD CAP SCREWS

GOVERNING STANDARDS:
ASTM A574 Covers the mechanical and material requirements for quenched and tempered alloy steel socket head cap screws.
ASME B18.3 Covers the complete general and dimensional data for various types of hexagon socket cap screws, shoulder screws and set screws.
ASME B1.1 UNRC & UNRF Class 3A (Class 2A above 1″) Specifies the thread form, series, class, allowance, tolerance, and designation for unified rounded root screw threads.

 

APPLICATIONS:

Socket head cap screws (also known as Allen head screws) have a cylindrical head with a flat chamfered top surface, knurled cylindrical sides and hexagon recess. Socket head cap screws are commonly used in applications in which it is necessary to recess the head of the fastener, as well as applications where space limits the size of the head, and the tool that drives the fastener. 

Socket Head Cap Screw Head

 

MATERIAL PROPERTIES:
Alloy Steel, Quenched and Tempered

DIAMETER

PROOF LOAD

YIELD STRENGTH

TENSILE STRENGTH

CORE HARDNESS

Through 1/2″ 162,000 psi 180,000 psi C39
5/8″ and Larger 153,000 psi 170,000 psi C37
Elongation 10% Minimum (Applies to machined specimens of length at least 4 X Diameter)
Reduction of Area 35% Minimum (All Diameters)
Material strengths listed are minimum acceptable per governing standard. Core hardness based on Rockwell scale.
DIMENSIONAL SPECIFICATIONS:

Socket Head Cap Screws Dimensional Data

 

Socket Head Cap Screws Length Specifications

Sources: ASTM Standards for Mechanical Fasteners and Related Processes 2nd Edition, Inch Fastener Standards 8th Edition, Kanebridge Fastener Reference Guide 4th Edition

Note: All material included on this page is informational only, and should not be used as one’s sole source for design purposes. STS Industrial, Inc. and its affiliates do not guarantee the accuracy of the information on this site, and retain no liability for the use or misuse of the information contained on this site.