Phillips Pan Head SEM Screws M2.5–M6 — Built-In Washers, Zero Assembly Hassle
Anyone who has fumbled with loose washers on a tight assembly knows the frustration — they fall, roll away, and slow down every job. These Phillips pan head SEM screws solve that problem by combining a spring washer and flat washer directly onto the shank, so every fastener arrives ready to install.
Machined from carbon steel with a zinc-plated (galvanized) finish, each screw follows the GB/T metric standard. Thread diameters run from M2.5 to M6 (approximately 0.098" to 0.236"), with shank lengths ranging from 5 mm to 50 mm (0.197" to 1.969") — all measured excluding the head. Packs are available in 20, 50, or 100 pieces to match your project scale.
Ideal for electronics enclosures, control panel assembly, light-gauge sheet metal work, appliance repair, and DIY machinery builds where a clean, secure, washer-backed connection is required without extra hardware.
✅ Compatible with standard ISO metric tapped holes and nuts — M2.5, M3, M4, M5, M6 thread pitch.
✅ Key Features of These Phillips Pan Head SEM Screws
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🔩 3-in-1 SEM design — spring washer + flat washer pre-assembled on shank; no loose hardware to manage
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⚙️ Carbon steel construction — zinc-plated finish for reliable strength and corrosion resistance in general-duty applications
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📐 Metric M2.5–M6 range — covers the most common machine screw sizes for electronics, panels, and light machinery
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📏 Multiple lengths available — 5 mm to 50 mm shank (excluding head) to suit shallow and deep fastening needs
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🔧 Phillips pan head drive — compatible with standard PH1/PH2 bits; fast installation with common tools
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📦 Bulk pack options — choose 20, 50, or 100 pieces; ideal for production runs, repairs, and stocking your toolbox
📐 Technical Specifications — Phillips Pan Head SEM Machine Screws
| Material |
Carbon Steel |
| Surface Treatment |
Zinc-plated (Galvanized) |
| Head Style |
Round / Pan Head |
| Drive Style |
Phillips (PH1 for M2.5–M3; PH2 for M4–M6) |
| Thread Standard |
GB/T (ISO Metric Compatible) |
| Thread Diameter |
M2.5 / M3 / M4 / M5 / M6 |
| Shank Length (Excl. Head) |
5 mm – 50 mm (0.197" – 1.969") |
| Washer Type |
Spring washer + flat washer (pre-assembled) |
| Pack Quantity |
20 / 50 / 100 pieces (select above) |
| Applicable Use |
Electronics, control panels, sheet metal, appliance repair, DIY machinery |
📌 Length note: All listed lengths are measured excluding the head. Factor in head height when calculating total fastener depth.
❓ Frequently Asked Questions
What does SEM screw mean?
SEM stands for Screw, External tooth lock washer, and flat washer — all pre-assembled onto the screw shank so you never lose a washer during installation. It saves time and prevents missing hardware on the job.
What size should I choose for my project?
Match the thread diameter (M2.5–M6) to your tapped hole or nut size. The listed length excludes the head — typically add 1–2 mm for clearance to ensure full thread engagement.
Are these screws corrosion resistant?
These carbon steel screws are zinc-plated (galvanized) for general indoor and light-duty outdoor use. For harsh or high-humidity environments, stainless steel alternatives are generally recommended.
What drive tool do I need?
A standard Phillips screwdriver or bit is required. M2.5–M3 typically use a PH1 bit; M4–M6 typically use a PH2 bit. Using the correct size prevents cam-out and head damage.
What thread standard do these follow?
These screws follow the GB/T metric standard, which is compatible with standard ISO metric threads. They will fit any standard metric tapped hole or nut of the corresponding size.
How many pieces come in each pack?
Available in packs of 20, 50, or 100 pieces. Select your preferred quantity from the variant options above before adding to cart.
Can I use these in electronics or precision assemblies?
Yes. The smaller sizes (M2.5–M3) are commonly used in electronics enclosures, PCB standoffs, and precision instrument panels where compact, secure fastening is needed without bulky hardware.
🛒 Select your diameter, length, and quantity above, then add to cart.
