Product Summary

Longze Precision Ultra-Thin & Flat Head Machine Screws are engineered for applications where vertical clearance is non-existent. Manufactured in Yongnian, China, our wafer

and flat head screws provide a secure mechanical bond without the protrusion of a standard hex or pan head. Whether for a slim-profile laptop chassis, a sliding door rail, or a flush-mount medical device, Longze low-profile screws offer the structural integrity of stainless steel with the aesthetic of a completely flat surface.

• ✔ Ultra-Low Profile Wafer Head: Our wafer screws feature a head height as thin as 0.5mm - 0.8mm, allowing for overlapping components to move freely without interference.

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• ✔ Precision 90° Countersink: Our flat head variants (DIN 965/ISO 7046) are forged with an exact conical angle to ensure a perfect flush-fit into pre-chamfered holes, eliminating snagging hazards.

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• ✔ Optimized Phillips Drive: Every cross-recess is cold-swaged to maximum depth allowed by the low-profile geometry, ensuring 100% bit engagement and preventing "cam-out" during high-speed automated assembly.

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• Standards: DIN 965 (Flat Head), ISO 7046, IFI (Wafer Head Custom), JIS B1111.

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• Diameter Range: M1.4 to M10 | #2 to 3/8".

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• Drive Types: Phillips (Cross Recess), Torx (6-Lobe), Slotted.

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• Material Grade: SS304 (A2-70), SS316 (A4-80), SS410 (Hardened).

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• Surface Finish: Passivated (Bright), Black Oxide (Stainless), Electropolished.

Mechanical Properties & Material Standards

• Matching the stainless grade to the structural requirements of the transmission line.

• Calificación	Material	Tensile Strength	Yield Strength	Hardness Range	Best Application
  SS304 (A2)	Acero inoxidable	700 MPa	450 MPa	200 - 280 HV	General Electronics
  SS316 (A4)	Acero inoxidable	800 MPa	600 MPa	240 - 320 HV	Marine / Outdoor
  SS410	Martensitic SS	1000+ MPa	900 MPa	35 - 45 HRC	Self-Tapping / Hard

Standard Cross Arm Dimensions

• Common dimensions for ultra-thin wafer head (Low Profile) metric screws.

• Thread Size (D)	Head Dia (dk)	Head Height (k)	Drive Size	Max Torque (SS304)
  M2	4.0 - 5.0 mm	0.5 - 0.6 mm	PH1	0.35 Nm
  M3	6.0 - 7.0 mm	0.8 - 1.0 mm	PH1	1.10 Nm
  M4	8.0 - 9.0 mm	1.0 - 1.2 mm	PH2	2.60 Nm
  M5	10.0 - 12.0 mm	1.2 - 1.5 mm	PH2	5.20 Nm

Passivation & Surface Integrity

• Ensuring 30+ years of service life in corrosive environments.

• Treatment	Process	Salt Spray Test	Appearance	Ambiente
  Passivation	Nitric Acid	144 - 240 Hours	Bright / Clean	Dry Indoor
  Black Oxide	SS Chemical	48 - 96 Hours	Matte Black	Dark Aesthetics
  Electropolished	Electrolytic	500 - 800 Hours	Mirror-Bright	Medical / Marine

Avoid Pitfalls:

• Phillips Drive Depth: Because the head is ultra-thin, the Phillips recess is naturally shallow. If the driver bit is worn, it will slip. Longze recommends using High-Precision Bits and considering Torx (6-Lobe) for sizes under M2.5 for better torque transfer.

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• Galling in Stainless Threads: Stainless-on-stainless assembly can "lock" or gall. We recommend a light wax coating or choosing our Passivated + Waxed series for automated assembly lines to ensure smooth seating.

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• Head Strength (The "Wafer" Risk): If the head diameter is too large compared to the thickness, it can cup or bend. We utilize Reinforced Cold Heading to ensure the head maintains its flat profile even under full tightening torque.

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Perfect Fit Assembly:

• Countersink Alignment: For flat head screws, ensure the workpiece's 90° countersink is concentric with the hole. Misalignment causes the screw to sit high on one side, ruining the flush finish.

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• Nylok Patches: For vibrating electronics (like servers or laptop fans), we can apply a Blue/Green Nylok patch to the threads to ensure they never vibrate loose.

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Quality Control & Logistics:

• ISO 9001 Certified: 5-step QC including Computerized Vision Sorting (to ensure head thickness consistency), thread gauge verification, and spectrometer material analysis.

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• Sea-Worthy Packaging: Screws are packed in small moisture-proof bags (e.g., 500 or 1000 pcs), then secured in reinforced master cartons for export from our Yongnian hub.

• Q: Can you provide these in black for high-end electronics? A: Yes, we offer a specialized Stainless Black Oxide that gives a premium matte finish without compromising the corrosion resistance of the SS304/SS316 base material.

• Q: Do you offer these in Imperial (#2-56, #4-40)? A: Absolutely. We manufacture a full range of Imperial low-profile machine screws for the North American medical and aerospace maintenance markets.