Product Summary

Longze Precision Ultra-Thin & Flat Head 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 Header: 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 7991/ISO 10642) are forged with an exact conical angle to ensure a perfect flush-fit into pre-chamfered holes, eliminating snagging hazards.

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• ✔ High-Torque Drive Options: Available with Torx (6-Lobe) O Phillips drives, cold-swaged to maximum depth to prevent stripping during high-speed automated assembly.

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• Standards: DIN 965, ISO 14581, IFI (Wafer Head Custom), JIS B1111.

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

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• Head Styles: Wafer (Ultra-Thin), Flat (Countersunk), Slim Head.

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• Drive Types: Torx (T-Drive), Phillips, Slotted, Hex Socket.

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• Material Grade: SS304 (A2), SS316 (A4), 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.

• Grado	Materiale	Tensile Strength	Yield Strength	Hardness Range	Best Application
  SS304 (A2)	Acciaio inossidabile	700 MPa	450 MPa	200 - 280 HV	General Electronics
  SS316 (A4)	Acciaio inossidabile	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	T6 / PH1	0.4 Nm
  M3	6.0 - 7.0 mm	0.8 - 1.0 mm	T10 / PH1	1.2 Nm
  M4	8.0 - 9.0 mm	1.0 - 1.2 mm	T20 / PH2	2.8 Nm
  M5	10.0 - 12.0 mm	1.2 - 1.5 mm	T25 / PH2	5.5 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:

• Drive Stripping (The "Low Head" Trap): Because the head is ultra-thin, the drive recess (socket) is also shallow. Longze recommends using Torx (6-Lobe) drives for M3 and smaller sizes to maximize torque transfer and prevent bit slippage.

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• Material Selection for Threading: If you are screwing directly into hard steel or aluminum, choose Hardened SS410 to ensure the threads don't collapse before fully seating.

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• The "Flush" Myth: For flat head screws, if the 90° chamfer in the workpiece is even 0.1mm too shallow, the screw will sit high. We provide Low-Profile Flat Heads with a slightly reduced head diameter to compensate for minor machining tolerances.

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Perfect Fit Assembly:

• Nylok Patches: For high-vibration electronics (like servers or automotive sensors), we can apply a Blue/Green Nylok patch to the threads to ensure they never vibrate loose.

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• Precision Driver Bits: Always use high-quality, CNC-ground driver bits. Worn-out bits are the #1 cause of head damage in ultra-thin screws.

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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 make the head even thinner than 0.5mm? A: For M2 and M2.5, we can achieve 0.4mm head thickness via specialized cold-heading, but we highly recommend a Torx drive to maintain installation torque.

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