Screws / SEMS ®

Screws from AALL AMERICAN Fasteners

The screw, long considered one of the world’s simple machines, is a solid cylinder wrapped with a helical plane.  To form a mechanical joint with a screw, the helical plane, referred to as the screw thread, rotates through a hole in the materials following or creating mating threads.

Screws are available in many sizes with different head and drive styles and thread pitches which vary depending on the material, method of installation and desired end result.

Screws having the ability to create mating threads as they are installed are referred to as self-tapping or self-drilling screws.  Self-tapping screws typically have threads down to the end or point of the screw and often require a pilot hole.  As they are installed, the self-tapping screw creates mating threads in the material.  Self-drilling screws on the other hand, do not require pre-drilled pilot holes as the tips are formed to drill the hole as they are installed.  The drilling tip is slightly smaller than the threads enabling the screw threads to form mating threads in the material.


Screw assemblies, referred to as SEMS, have a free-spinning washer or washers permanently attached under the screw head.  SEMS save time during assembly and afford the same benefits as non-attached washers such as distributing load, acting as a spacer, reducing vibration and acting as a protective barrier.

*Note:  For additional standard or custom SEMS configurations, contact our Certified Fastener Experts at 877-791-4426.

Contact AALL AMERICAN Fasteners today for screws, SEMS, and more

Please contact our Certified Fastener Specialists to review your screw and SEMS requirements at 877-791-4426 or send your Request For Quote to us directly.

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