SLOTTED ROUND EXTERNAL TOOTH LOCKWASHER	UNSLOTTED INDENTED HEX LOCKWASHER	SLOTTED PAN SPLOT LOCKWASHER
CROSS RECESSED PAN INTERNAL TOOTH LOCKWASHER	SLOTTED OVAL EXTERNAL COUNTERSUNK LOCKWASHER	CROSS RECESSED PAN INTERNAL/EXTERNAL LOCKWASHER

Sems screws are convenient screw and washer assemblies. The washer is slipped onto the screw body during manufacturing, just before rolling the threads. When the threads are rolled, they captivate the washers and keep them from becoming disassembled. Although the initial cost per fastener may be a bit more, in high volume production you will quickly see assembly time cost savings.

Sems screws can be ordered with various combinations of head styles, washers styles, thread styles, materials and plating types catering to your specific requirements. The head style and drive which you prefer can be combined with either a machine screw thread or any form of tapping screw thread. Any washer combination you need can be special ordered if not available from stock. Work hardened materials are available in machine screw threads and heat-treated materials (for greater strength) are available in tapping screw threads.

Security screws are available in pan, round, truss, oval, flat, button and socket cap head styles. They may have either machine screw threads or sheet metal threads. The most readily available materials are zinc plated steel and for more severe environments - stainless steel. Other materials may be available by special order. Installation and removal power tool bits and hand tools are available also. Ask your sales representative for more information. For a quick comparison of cost vs. degree of security see reference chart below.