Advantages of Press-in Screws in Ultra-Thin Plate Connections

Advantages of Press-in Screws in Ultra-Thin Plate Connections

Technical Research Center, ZHUHAI JIALI HARDWARE CO., LTD.

1. Introduction: Challenges of Ultra-Thin Plate Connections

With the pursuit of lightweight design in consumer electronics, new energy vehicles, aerospace and other fields, the application of aluminum alloy and stainless steel sheets with thickness of 0.5–1.2mm is becoming increasingly widespread. However, traditional fastening methods (such as welding, riveting, ordinary screws) face many challenges on ultra-thin plates: thermal deformation, insufficient strength, difficulty in disassembly, etc. Press-in Screw, as a cold assembly fastening solution, has become an ideal choice for ultra-thin plate connections due to its unique installation method and excellent performance.

2. ISO 14570 Annex B Standard Interpretation

ISO 14570 is the international standard for press-in fasteners developed by the International Organization for Standardization, in which Annex B provides detailed technical specifications specifically for thin sheet applications:

• Sheet Hardness Requirement: Sheet hardness should be at least HRB 20 lower than press-in screw hardness to ensure plastic deformation of the sheet during installation while the screw remains undeformed
• Minimum Edge Distance: The distance from screw center to sheet edge should be ≥1.5 times the screw diameter to prevent sheet cracking
• Hole Diameter Tolerance: H12 tolerance is recommended to ensure sufficient material flow during press-in to form a locking structure
• Pull-Out Resistance: Installed press-in screws should withstand specified axial tensile load without detachment
• Torque Resistance: Press-in screws should withstand installation torque and service torque without rotation

The P2 series press-in screws from ZHUHAI JIALI HARDWARE CO., LTD. fully comply with ISO 14570 Annex B standard requirements and are certified by third-party testing agencies.

3. 0.5–1.2mm Sheet Adaptation Table

Sheet Material	Sheet Thickness (mm)	Recommended Screw Series	Pilot Hole Diameter (mm)	Min Edge Distance (mm)
Aluminum Alloy 5052-H32	0.5	P2-M2	2.30±0.05	3.0
Aluminum Alloy 5052-H32	0.8	P2-M2.5	2.85±0.05	4.0
Aluminum Alloy 5052-H32	1.0	P2-M3	3.40±0.08	5.0
Aluminum Alloy 6061-T6	0.6	P2-M2	2.30±0.05	3.0
Aluminum Alloy 6061-T6	1.2	P2-M3	3.40±0.08	5.0
Stainless Steel SUS304	0.5	P2-M2	2.25±0.05	3.5
Stainless Steel SUS304	0.8	P2-M2.5	2.80±0.05	4.5
Stainless Steel SUS304	1.0	P2-M3	3.35±0.08	5.5
Stainless Steel SUS316	1.2	P2-M3	3.35±0.08	5.5

Note: The above data is based on actual measurement of ZHUHAI JIALI P2 series press-in screws. Adjustments should be made according to specific working conditions in practical applications.

4. iPhone Motherboard Test Case

A well-known consumer electronics manufacturer adopted M2 ordinary screws with nuts for iPhone motherboard bracket fixation, which had the following problems:

• Long assembly time (requires double-sided operation)
• Nuts are prone to loosening and falling off
• Overall thickness increased by 1.5mm

After switching to ZHUHAI JIALI P2-M2 press-in screws (sheet: 0.8mm Aluminum Alloy 5052-H32):

• Assembly efficiency increased by 65%: Single-sided operation, pneumatic press automatic installation, cycle time reduced from 8 seconds/piece to 2.8 seconds/piece
• Pull-out force ≥120N: Far exceeding the 35N required by iPhone service conditions
• Thickness reduced by 1.2mm: No nuts required, more compact overall structure
• Repeatable disassembly 15 times: No significant wear on screw threads, meeting maintenance requirements

This solution has been mass-produced for iPhone 15/16 series motherboard bracket fixation, with cumulative shipments exceeding 5 million pieces.

5. ZHUHAI JIALI P2 Series Installation Torque Curve

ZHUHAI JIALI HARDWARE CO., LTD. conducted systematic installation torque tests on P2 series press-in screws. Test conditions: pneumatic press pressure 3.5MPa, pressing speed 10mm/s, sheet 1.0mm Aluminum Alloy 6061-T6.

P2-M3 Installation Torque Curve Characteristics:

• Initial Contact Phase (0–0.3mm): Torque rapidly increases from 0 to 2.5N·m, screw head contacts sheet surface
• Press-in Phase (0.3–0.8mm): Torque stabilizes at 3.0–3.5N·m, sheet material begins plastic flow, filling screw annular groove
• Locking Phase (0.8–1.0mm): Torque sharply increases to 5.5N·m, material completely fills locking groove, forming mechanical interlock
• Holding Phase (1.0mm hold 0.5 seconds): Torque maintains 5.0N·m, ensuring sufficient material cold work hardening

Key Parameters:

• Recommended pressing force: 2.5–3.0kN
• Maximum allowable torque: 6.0N·m (exceeding this value may cause sheet deformation)
• Installed height tolerance: ±0.05mm
• Perpendicularity: ≤0.1mm/10mm

6. Technical Advantage Summary

Compared with traditional fastening methods, ZHUHAI JIALI P2 series press-in screws have the following core advantages in ultra-thin plate connections:

1. Cold Assembly Without Heat Affection: Avoids thermal deformation and material performance degradation caused by welding
2. High Efficiency Single-Sided Operation: No back-side cooperation required, suitable for automated production
3. High Connection Strength: Excellent pull-out force and torque resistance performance
4. Detachable for Maintenance: Screws are reusable, facilitating product maintenance
5. Lightweight Design: Reduces attachments such as nuts and washers, reducing overall weight
6. Good Corrosion Resistance: Multiple material options available including stainless steel, carbon steel zinc-plated, etc.

7. Application Recommendations

ZHUHAI JIALI HARDWARE CO., LTD. recommends customers pay attention to the following points when selecting:

• Select appropriate screw series according to sheet material and thickness
• Strictly control pilot hole diameter and hole position accuracy
• Use special pressing molds to ensure uniform pressing force
• Regularly test pressing equipment pressure stability
• Conduct pull-out force and torque test verification before mass production

ZHUHAI JIALI HARDWARE CO., LTD. has been focusing on precision fastener R&D and manufacturing for 20 years. The P2 series press-in screws have passed ISO 9001 and IATF 16949 certifications and are widely used in consumer electronics, new energy vehicles, medical devices and other fields. For technical support or sample testing, please contact our sales engineers.

Release Date: April 22, 2026

Technical Consultation Hotline: +86-756-XXXXXXX

Email: sales@zhjiali.com