Phillips Pan Head Sems Machine Screws Double Washer Flat And Spring M3 M4 M5 For Electronics Enclosure
Two workers are assembling control panels. One picks up a screw, then a washer, slides the washer onto the screw, and drives it in. The other picks up one part — a screw with the washer already on it — and drives it in.
The second worker finishes faster. That is the difference a sems screw makes.
A sems screw is a screw with a washer already fitted under the head. The washer spins freely but stays on the screw. It cannot fall off. You grab one part instead of two. Assembly goes faster. Washers do not get lost.
Time is money on a production line. Picking up two parts instead of one takes extra seconds. Those seconds add up over hundreds of screws. Sems screws cut that time. They also reduce inventory — one SKU instead of two.
Spring washer. Stops screws from shaking loose. Use it on machinery, motors, and anything that vibrates.
Flat washer. Spreads clamping pressure over a wider area. Use it on soft materials like plastic and aluminum.
External tooth lock washer. Teeth bite into the surface. Use it when vibration is severe.
Internal tooth lock washer. Teeth grip the screw head. Use it when you want a clean outward appearance.
Double washer. Spring washer plus flat washer together. Anti vibration and pressure distribution in one screw.
Phillips pan head is the standard. Works with any Phillips screwdriver. Wide bearing surface for clamping.
Hex head takes a wrench or socket. Good for higher torque applications.
304 Stainless Steel Resists rust. Use it outdoors or in wet areas.
316 Stainless Steel Offers extra protection. Use it near saltwater.
Zinc Plated Carbon Steel Strong and budget friendly. Use it indoors or light outdoor.
M3, M4, M5, M6. Lengths 6mm to 30mm. Grade 8.8 for most jobs. Grade 10.9 for heavier loads. Grade 12.9 for the toughest applications.
Electronics assembly. PCB mounting. Control panels. Industrial equipment. Automotive parts. Marine enclosures. HVAC units. Anywhere you want to move fast and not worry about loose washers.
YH Fastener has been making fasteners since 1998. Our range includes sems screws, self tapping screws, machine screws, shoulder screws, and custom fasteners. ISO 9001 and ISO 10012 certified. Every batch inspected. Factory direct. Ship to 60+ countries.
