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Product Description : As a basic fastening component in fields such as home assembly, electronic equipment, and light industry manufacturing, the plastic nylon pan-head slotted machine screw has become an ideal choice for low-load scenarios, thanks to the insulation and lightweight properties of nylon material, as well as the convenient driving feature of its pan-head slotted structure.

 Multi-Specification Classification Logic: Divided by Core Parameters

The specification classification of plastic nylon pan-head slotted machine screws takes "thread diameter" as the core dimension, and forms differentiated combinations with "screw length" to cover fastening needs from micro to medium sizes. Common specifications can be divided into three categories:

1. Micro Specifications (M1.4-M2.5)

Focusing on "small size and high precision", they are suitable for fixing micro-components of electronic equipment and precision instruments. With a thread diameter of 1.4mm-2.5mm and a screw length (excluding the head) of 3mm-10mm, typical models include M1.4×3, M2×5, and M2.5×8. They are often used for fixing circuit boards and installing small sensors. Their slender thread design can avoid damaging soft substrates (such as PCB boards and plastic housings).

2. Regular Specifications (M3-M5)

As the most widely used mainstream specifications, they are suitable for scenarios such as home assembly and small household appliance manufacturing. With a thread diameter of 3mm-5mm and a screw length of 5mm-20mm, typical models include M3×6, M4×10, and M5×16. They can be used to fix furniture laminates, household appliance panels, and plastic casings, balancing fastening strength and operational convenience.

3. Medium Specifications (M6-M8)

Designed for slightly higher load requirements, they are suitable for fixing non-load-bearing components of light machinery and outdoor facilities. With a thread diameter of 6mm-8mm and a screw length of 10mm-30mm, models such as M6×12 and M8×25 can be used to fix small storage racks and outdoor awning brackets. Their thicker threads and longer engagement length provide more stable support.

 Detailed Dimensional Standards: Key Parameters and Industry Norms

Based on GB/T 65-2016 (Standard for Pan-Head Slotted Machine Screws) and the characteristics of nylon material, the core dimensions of plastic nylon pan-head slotted machine screws must meet the following standards to ensure versatility and reliability:

1. Thread Size: Unified Precision and Tooth Profile

The thread type is "ordinary coarse thread", and the pitch strictly complies with standards: M1.4 (0.3mm), M2 (0.4mm), M3 (0.5mm), M4 (0.7mm), M5 (0.8mm), M6 (1.0mm), M8 (1.25mm) — ensuring perfect engagement with nuts and threaded holes of the same specification. The thread precision is 6g (external thread), and the tolerance range of major diameter, pitch diameter, and minor diameter must be controlled within ±0.02mm-±0.05mm (smaller diameters have stricter tolerances) to avoid thread slipping or loose fastening caused by thread deviation.

2. Head Size: Adapting to Tool Use and Aesthetic Needs

The size of the pan-head must balance "driving convenience" and "surface fit":

• The head diameter (d) is 1.5-1.8 times the thread diameter. For example, the head diameter of an M3 screw is 5.5mm±0.2mm, and that of an M5 screw is 8.5mm±0.3mm.

• The head height (k) is 0.8-1.0 times the thread diameter. The head height of an M3 screw is 2.0mm±0.15mm, and that of an M5 screw is 3.0mm±0.2mm. This ensures sufficient structural strength while preventing the head from being too high to affect appearance or interfere with other components.

The slotted size is crucial:

• The slot width (n) must be accurately matched with the flat-head screwdriver bit: 1.0mm-1.5mm for M1.4-M2.5, 1.5mm-2.0mm for M3-M5, and 2.0mm-3.0mm for M6-M8.

• The slot depth (t) must reach 1/2-2/3 of the head height. For example, the slot depth of an M3 head is ≥1.0mm, and that of an M5 head is ≥1.5mm. This ensures no slipping when driving with a screwdriver and prevents head breakage caused by excessive slot depth.

3. Screw Length: Adapting to the Thickness of Connected Components

The screw length (L, excluding the head) should be selected based on the total thickness of the connected components. The standard length series includes 3mm, 4mm, 5mm, 6mm, 8mm, 10mm, 12mm, 16mm, 20mm, 25mm, and 30mm. The interval follows the principle of "dense for small specifications, sparse for large specifications" (1mm interval for M1.4-M2.5, 5mm interval for M6-M8). When selecting, ensure the length of the screw screwed into the threaded hole is ≥1.5 times the thread diameter (e.g., an M3 screw needs to be screwed in ≥4.5mm), and the exposed length is ≤1mm to avoid interference from excessive length or insufficient fastening strength from excessive shortness.

 Core Role of Dimensional Standards: Ensuring Adaptability and Safety

Strict dimensional standards are the basis for plastic nylon pan-head slotted machine screws to achieve "cross-scenario versatility", and their core value is reflected in three aspects:

1. Tool Adaptability

Unified slotted dimensions (width and depth) ensure that screws of different brands and specifications can be operated with a universal flat-head screwdriver, eliminating the need for special tools. This lowers the use threshold and is especially suitable for DIY scenarios by ordinary users (such as home assembly).

2. Connector Compatibility

Standardized thread and head sizes enable precise matching with prefabricated threaded holes (such as plastic expansion tubes and nylon nuts), avoiding installation difficulties caused by dimensional deviations. For example, an M4 screw can perfectly fit a nylon nut with an inner diameter of 4mm, and its head diameter of 8.5mm can cover the mounting holes (9mm-10mm in diameter) of common plastic panels, achieving tight fitting.

3. Safety and Reliability

The mechanical properties of nylon material change with size (larger diameter means higher strength). Dimensional standards can help judge load adaptability: for example, an M3 screw has a tensile strength of approximately 500N and is only suitable for fixing components ≤1kg; an M8 screw has a tensile strength of approximately 1500N and can bear a static load ≤5kg. This avoids the risk of component falling caused by improper specification selection.

Selection Suggestions: Matching Specifications by Scenario

• Electronic Equipment Scenarios: Prioritize micro specifications (M1.4-M2.5). For example, use M2×5 to fix PCB boards, ensuring the thread does not penetrate the substrate and the head height does not interfere with components.

• Home Assembly Scenarios: Regular specifications (M3-M5) are preferred. For example, use M4×16 to fix furniture laminates — the length should penetrate the laminate (15mm thick) and then be screwed into the cabinet by 2mm-3mm.

• Outdoor Light-Duty Scenarios: Medium specifications (M6-M8) are more suitable. For example, use M6×12 to fix plastic awning brackets, and match with nylon washers to enhance sealing and prevent rainwater infiltration.