Sems Screws
Pan Head Phillips Sems Screw Pre Assembled Combination Machine Screws
Pan Head Sems Screw
Our factory produces premium pan head sems screw (also called combination machine screw), pre-assembled with flat washer and spring washer as one integrated fastener. Unlike separate screws and loose washers, our all-in-one sems screw eliminates messy assembly sorting, greatly boosting production efficiency for electronics cabinets, PCB boards and automation equipment. The smooth pan round head and cross Phillips recess ensure stable screwdriver engagement without slipping during tightening.
Core Product Advantages
- Integrated triple assembly structure: screw + flat washer + spring washer fixed permanently, no washer loss during mass assembly
- Spring washer provides continuous anti-loosing tension to resist vibration loosening for long-term equipment operation
- Multiple head & drive options: pan Phillips, hex cross, torx, square drive to match different assembly tools
- Dual anti-corrosion solutions: zinc plating / black oxide carbon steel, passivated 304 stainless steel for humid environments
- Full metric stock M3, M4, M5, M6; custom thread length, head diameter and washer thickness supported
- Small trial orders & bulk wholesale available, free sample testing before mass production
Rich Material & Surface Custom Options
Raw Material Selection
- Carbon Steel (Grade 4.8 / 8.8): Low cost, high tensile strength for indoor general machinery assembly
- SUS304 Stainless Steel: Excellent rust resistance, ideal outdoor, medical and electronic devices with moisture exposure
- Custom alloy material available for special high-temperature or anti-static requirements
Surface Finishes
Zinc blue-white plating, black oxide, black nickel, stainless steel passivation, bright polishing, plastic coated insulating washer customization. All finishes pass salt spray anti-rust testing per customer demands.
Optional Washer Configurations
Standard metal flat + spring dual washers; customized plastic isolation washer, EPD waterproof washer, external tooth lock washer for grounding applications.
Diversified Head & Drive Types
We supply multiple variants of sems screw beyond standard pan Phillips design:
- Pan head Phillips cross recess (mainstream electronic cabinet fastener)
- Hexagon pan cross sems screw for high torque locking
- Hex socket cap combination screw for precision machinery
- Miniature precision SEM anti-static sems screw for laboratory instruments
- Custom small pan head screw with plastic isolation washer for circuit boards
Wide Industry Application Scenarios
Our pan head sems screw is widely adopted across manufacturing industries:
Electronic equipment enclosures, PCB board mounting, server cabinet assembly, household appliances, automation machinery, medical testing instruments, communication devices, laboratory precision equipment, office hardware, sheet metal cabinet fixing.
Stainless steel sems screw is highly recommended for outdoor equipment, humid workshop and medical sanitary equipment.
OEM & Customization Service Flow
- Submit drawings, dimension lists or physical samples with your special sems screw demands
- Our engineering team reviews tolerances and optimizes structure for better assembly performance
- Arrange free prototype samples for quality and fit confirmation
- Start mass production after sample approval, flexible MOQ for small batches
- Custom neutral export packaging, mixed size carton packing, on-time global shipping
Factory Production Strength
We are a professional sems screw manufacturer with full automatic stamping, threading and pre-assembly production lines. Every batch of combination screws undergoes strict inspection for thread precision, washer tightness and surface anti-rust quality.
Our factory complies with ISO quality standards, all materials meet RoHS environmental requirements. We have rich experience cooperating with electronic factories, machinery manufacturers and hardware wholesalers worldwide, offering stable lead time for repeated bulk orders.
Frequently Asked Questions
Q1: What is the advantage of integrated sems screw over separate screws and washers?
A: Pre-fixed washers avoid missing parts during assembly, cut manual sorting labor cost; spring washer keeps sustained preload to prevent loosening under machine vibration.
Q2: Can I customize non-standard pan head sems screw sizes?
A: Yes. We fully customize thread length, head thickness, washer thickness, drive type and special coating according to your technical drawings.
Q3: How long can I get quotation and free samples?
A: Complete formal quotation sent within 12 working hours; samples finished within 3-7 working days and delivered by express for your testing.
Q4: Are stainless steel sems screw suitable for marine wet environments?
A: SUS304 stainless steel combination screws have good anti-rust performance for general damp scenarios; SUS316 material is available for severe saltwater corrosion environments upon request.