This standard specifies the product classification, technical requirements, test methods, inspection rules and marking, packaging, transportation and storage of watch springs (referred to as "springs"). This standard applies to ordinary mechanical watch springs. QB/T 2404-1998 Watch Springs QB/T2404-1998 Standard download decompression password: www.bzxz.net

QB/T2404—1998
—1983 "Watch Spring" was revised and adjusted to the industry standard. During the revision process, the technical elements of the original national standard GB4036-1983 were partially adjusted and supplemented. The main differences between this standard and the original GB4036-1983 are: the relevant technical indicators of non-self-lubricating springs were cancelled, the torque change rate of springs was revised, and the export inspection and type inspection were added. This standard was proposed by the Industry Management Department of the State Bureau of Light Industry. This standard is under the jurisdiction of the National Clock and Watch Standardization Center. The drafting unit of this standard: Xi'an Clock and Watch Component Factory. The main drafters of this standard: Wu Xinjian, Sun Yufeng. From the date of implementation of this standard, the original national standard GB4036-1983 "Watch Spring" will be abolished. 470
Light Industry Standard of the People's Republic of China
Watch Spring
QB/T2404—1998
This standard specifies the product classification, technical requirements, test methods, inspection rules and marking, packaging, transportation and storage of watch springs (hereinafter referred to as springs).
This standard applies to ordinary mechanical watch springs. 2 Cited standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards will be revised, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB/T2828--1987 Batch inspection counting sampling procedures and sampling tables (applicable to inspection of continuous batches) GB/T2829~1987 Periodic inspection counting sampling procedures and sampling tables (applicable to inspection of production process stability) QB/T124 9--1991
Ordinary mechanical watches
3Product classification
The width of the spring and the size of the square hole are shown in Table 1. Table 1
4Technical requirements
4.1Performance
The mechanical properties of the spring are shown in Table 2.
4.2Dimensional accuracy
The dimensions and accuracy of the spring are shown in Table 3.
Approved by the State Bureau of Light Industry on November 25, 1998
0.4×1.20
0.5×1.60
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0. 5×1, 60
0. 7 X1. 70
1999-06-01 implementation
Small torque attenuation rate +%
Torque change rate, %
Working number
Fatigue breaking number
Outer hook fastness
Note: Na6 is the working number of the watch spring for 36 hours. Item
Inner circle diameter
Outer hook clearance
4.3 Appearance quality
QB/T2404| |tt||—1998
4000 times
After withstanding a torque of 24.5×10-Nm, the outer hook does not fall off Table 3
4.3.1 The metal surface of the spring is not allowed to have rust spots and obvious scratches. 4.3.2 The plastic-coated surface of the spring is not allowed to have coating shedding and obvious oxidation color. 4.4 Other special requirements shall be agreed upon by the supply and demand parties. 5 Test method
5.1 Working turns
0. 05~ 0.30
After installing the mainspring into the standard barrel wheel component, test it on the torque meter. First, fully wind the mainspring, and measure the large torque (MT) when it is withdrawn 1/4 turn. When it is withdrawn to the number of turns equivalent to 24 hours of watch running (including the 1/4 turn that has been withdrawn), measure the small torque (MT24). When the torque is zero, read the working figure. When the barrel wheel component slips during the torque measurement, only one replacement is allowed. 5.2 Number of fatigue broken bars
Put the mainspring on the fatigue meter for testing, and measure the number of times it curls and stretches between large and small torques, which is the number of fatigue times. The time for curling and stretching once is 3s.
5.3 Small torque decay rate
After measuring the small torque value of the mainspring according to the method in 5.1, test the small torque value after 1800 fatigue tests, and substitute its value into formula (1) to calculate the small torque decay rate.
= Mr= M × 100
Where: -—Small torque attenuation rate, %
Mr24——Torque of the spring for 24 hours (i.e. small torque), N·mzMTF24
Small torque measured after 1800 fatigue times, N·m. 5.4 Torque variation rate
Measure the large and small torque values ​​of the spring according to the method in 5.1, and substitute them into formula (2) to calculate the torque variation rate. Mro=Mr2d × 100
—Torque variation rate, %
Where B-
QB/T2404—1998
MTo—Full spring torque (i.e. large torque), N·mMr34—Torque of the spring for 24 hours (i.e. small torque), N*m. 5.5 External hook fastness
Put the spring on a torque meter with a standard spring of 24.5×10-3N·m for testing. After tightening, the external hook cannot fall off. 5.6 Dimensional accuracy
5.6.1 The width of the spring is measured with a micrometer.
5.6.2 The internal diameter of the spring is measured with a special plug gauge. In case of dispute, a 50× projector can be used for measurement. The measurement method is shown in Figure 1. y
5.6.3 The clearance of the external hook is measured with a 50× projector. 5.7 Appearance quality
Visual inspection is performed at a distance of 300mm from the surface of the tested piece under natural light. '6 Inspection rules
6.1 Factory inspection
6.1.1 Factory inspection is carried out in accordance with GB/T2828, using a single sampling plan. The unqualified categories, inspection items, inspection levels (IL), and qualified quality levels (AQL) are shown in Table 4.
Unqualified categories
Inspection items
Working circumference
Torque change rate
External hook rate
Inner diameter
External hook clearance
Appearance quality
Corresponding clauses
4.2,5.6.2
4.2.5.6.3
4.2,5.6.1
Inspection level
6.1.2 The composition of the batch and the batch shall be agreed upon by the supply and demand parties. 6.1.3 The implementation of the inspection, the qualified judgment and the post-inspection disposal shall be carried out in accordance with the relevant provisions of GB/T2828. Qualified quality level
6.2 Type inspection
6.2.1 Type inspection shall be carried out in accordance with GB/T2829. A single sampling plan is adopted. The unqualified categories, inspection items, discrimination level, unqualified quality level (RQL), sample number and judgment array are shown in Table 5. 473
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Unqualified categories
Inspection items
Working countries
Small torque capsule reduction
Torque change rate
External hook fastness
Internal Circumference diameterwwW.bzxz.Net
Outer hook clearance
Fatigue bar breaking times
Appearance quality
Corresponding clauses
4.2,5.6.2
4.2.5.6.3
QB/T2404—1998
Discrimination level
4.2.5.6.1
Unqualified quality level
Number of samples
Samples for type inspection shall be randomly selected from a batch or batches that have passed the factory inspection, and the spare samples shall be determined by the inspection unit. 6.2.2
6.2.3 The implementation of the inspection, the determination of qualification and the disposal after the inspection shall be carried out in accordance with the relevant provisions of GB/T2829. 6.2.4 The cycle of type inspection shall be determined by each production unit, but type inspection shall be carried out in any of the following situations. a) When a new product is put into production or an old product is switched to another product; b) When there are major changes in the design, structure, process, or materials of a product; c) When a product is resumed after a long period of suspension; d) When the national quality supervision agency requires a type inspection. 7 Marking, packaging, transportation, and storage
7.1 Marking
Each packaging container of a spring product should contain a product certificate and indicate: a) the name and address of the manufacturer;
b) specifications;
c) trademark;
d) implementation standard number;
e) batch number and quantity;
f) inspector's seal,
g) date of manufacture.
7.2 Packaging
The packaging of spring products shall be agreed upon by both the supplier and the buyer. 7.3 Transportation and storage
During transportation and storage, it is strictly forbidden to press heavy objects on the product, and it must be handled with care and avoid moisture. The storage environment should be kept ventilated and dry, and should not be placed together with items containing corrosive gases.
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