GB 1184-2010 Square Wing Thumb Screws Standard
1. Introduction
Square wing thumb screws, also known as butterfly screws with square wings, are essential fasteners designed for manual tightening without tools. They play a critical role in industries requiring quick assembly and disassembly, such as machinery, furniture, and automotive applications.
The GB 1184-2010 standard provides specifications for these screws, ensuring consistency in dimensions, tolerances, and performance. This standard, an update from previous versions, focuses on metric thread sizes from M3 to M20, including optional sizes like M14 and M18.
Applications include securing panels, clamps, and fixtures where frequent adjustments are needed. The standard divides specifications into key parameters like head diameter, wing span, and height, as detailed in the table below.
Table 1: Key Parameter Ranges
| 范围 | 描述 | Range (mm) |
|---|---|---|
| dk (min) | Head diameter minimum | 6.5 to 27 |
| k (min) | Head height minimum | 3 to 12 |
| n | Wing width (nom/max/min) | 17 to 68 |
| H | Wing height (nom/max/min) | 9 to 35 |
This standard specifies wing spans from 17 mm to 68 mm, ensuring ergonomic design. For dimensions outside this range, custom tolerances may apply, potentially increasing manufacturing uncertainty due to material limitations.
The standard also outlines periodic inspection methods for production equipment. It applies to materials like stainless steel, carbon steel, and alloys, including coated variants for corrosion resistance.
It is suitable for screws with thread lengths allowing accurate assembly, but not for ultra-short threads under 0.030 mm in specific applications. Specialized standards govern unique materials or products.
2. GB 1184-2010 Standard Overview
Released in 2010, this standard supersedes earlier versions, incorporating updates for improved precision and international alignment.
Scope: Defines dimensions and tolerances for square wing thumb screws with metric threads. It covers sizes M3 to M20, focusing on hand-operated fasteners.
Main content includes dimensional tables, material recommendations, and tolerance classes.
3. Basic Principles of Square Wing Thumb Screws
Square wing thumb screws are defined as threaded fasteners with square-shaped wings for manual torque application.
The design principle involves leveraging wing leverage for easy tightening. Torque is applied via fingers or thumbs, eliminating tool needs.
Calculation of effective torque considers wing span (n) and material strength, typically using formulas like T = F × (n/2), where T is torque and F is applied force.
4. Dimensions and Specifications
The standard outlines precise dimensions for various thread sizes.
4.1 Manufacturing Temperature
Production typically occurs at room temperature (10°C to 35°C). Deviations must be noted in reports. For precision, maintain 23°C ± 5°C.
4.2 Key Dimensions
Typical dimensions are provided for thread sizes M3 to M20. Select sizes to ensure wing spans meet ergonomic requirements.
Table 2: Detailed Dimensions (units: mm)
| 范围 | M3 | M4 | M5 | M6 | M8 | M10 | M12 | (M14) | M16 | (M18) | M20 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| dk min | 6.5 | 6.5 | 8 | 10 | 13 | 16 | 20 | 20 | 27 | 27 | 27 |
| k min | 3 | 3 | 4 | 4.5 | 6 | 7.5 | 9 | 9 | 12 | 12 | 12 |
| n nom | 17 | 17 | 21 | 27 | 31 | 36 | 48 | 48 | 68 | 68 | 68 |
| n max | 18.5 | 18.5 | 22.5 | 28.5 | 33 | 38 | 50 | 50 | 70 | 70 | 70 |
| n min | 15.5 | 15.5 | 19.5 | 25.5 | 29 | 34 | 46 | 46 | 66 | 66 | 66 |
| H nom | 9 | 9 | 11 | 13 | 16 | 18 | 23 | 23 | 35 | 35 | 35 |
| H max | 10.5 | 10.5 | 12.5 | 14.5 | 17.5 | 19.5 | 24.5 | 24.5 | 37 | 37 | 37 |
| H min | 7.5 | 7.5 | 9.5 | 11.5 | 14.5 | 16.5 | 21.5 | 21.5 | 33 | 33 | 33 |
| h1 最大限度 | 3 | 3 | 3.5 | 4 | 4.5 | 5.5 | 7 | 7 | 8 | 8 | 8 |
| h2 最大限度 | 4 | 4 | 4.5 | 5 | 5.5 | 6.5 | 8 | 8 | 9 | 9 | 9 |
5. Sample Preparation and Requirements
Screws must be manufactured from clean, defect-free materials. Equipment includes forging machines and thread rollers configured per standard tolerances.
Steps: Material selection, forging wings, threading, inspection for dimensions using calipers and gauges.
Analyze data against table values for compliance.
6. Testing Precision and Error Analysis
Error sources include material variability, machining inaccuracies, and measurement tools.
Improve accuracy via calibrated instruments and controlled environments.
Common errors: Oversized wings; solutions: Adjust dies and verify post-production.
7. GB 1184-2010 Standard’s Impact on Industry
It influences fastener design in R&D, ensuring interoperability.
Enhances quality control through standardized inspections.
Applications: Automotive assembly lines, machinery maintenance, furniture production.
8. Frequently Asked Questions
What materials are recommended for GB 1184-2010 square wing thumb screws?
Common materials include stainless steel (e.g., AISI 304) for corrosion resistance and carbon steel for general use. Coatings like zinc plating enhance durability.
How do square wing thumb screws compare to round wing variants?
Square wings provide better grip for higher torque, while round wings are smoother for frequent handling. Choose based on application ergonomics.
What tolerances apply to dimensions in this standard?
Tolerances are typically ±0.5 mm for wing dimensions, ensuring fit without excessive play. Refer to GB/T 1184 for general geometrical tolerances.
Can these screws be used in high-vibration environments?
Yes, with locking mechanisms like washers. The standard focuses on dimensions, but material strength ratings (e.g., 8.8 grade) ensure reliability.
How to select the appropriate thread size?
Base selection on load requirements and mating components. For example, M8 for medium loads, M20 for heavy-duty applications.
Are optional sizes like M14 mandatory?
No, (M14) and (M18) are optional, used when standard sizes do not suffice. Consult manufacturers for availability.
