This standard specifies the product classification, technical requirements, test methods, inspection rules and marking, packaging, transportation and storage of thread take-up screws for household sewing machines. This standard applies to thread take-up screws for JA type household sewing machines. QB/T 2146-1995 Thread take-up screws for household sewing machines QB/T2146-1995 Download the standard with the decompression password: www.bzxz.net

Light Industry Standard of the People's Republic of China
Thread take-up lever screw for household sewing machines
1 Subject content and scope of application
QE/T2146-1995
This standard specifies the product classification, technical requirements, test methods, inspection rules and marking, packaging, transportation and storage of thread take-up lever screws for household sewing machines.
This standard applies to thread take-up lever screws for JA type household sewing machines. 2 Reference standards
Pictorial marking for packaging, storage and transportation
GB/T 2828
GB/T 2829
Counting sampling procedures and sampling tables for batch inspection (applicable to inspection of continuous batches)Counting sampling procedures and sampling tables for periodic inspection (applicable to inspection of stability of production process)QB/T1512
Limit deviations of dimensions without tolerances for sewing machine partsZBY 17004
ZBY 17011
ZBY 17012
ZBY 17015
3 Product categories
Sewing machine packaging
Special thread for sewing machines
Technical conditions for blackening of sewing machine parts
General technical conditions for heat treatment of sewing machine partsSee Figure 1 for structural dimensions.
4 Technical requirements
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4.1 Thread SM15/64\X28 according to the second level accuracy requirement of 6.2 in ZBY17011. 4.2 Head outer diameter g16mm and screwdriver slot width 1.5mm according to the C level requirement of 4.1.1 in QB/T1512. 4.3 Shoulder outer diameter $9,50.00gmm.
Approved by China Light Industry General Association on October 24, 1995
Implemented on June 10, 1996
4.4 Shoulder height 2.2+8.88mm
QB/T2146--1995
4.5 Surface roughness The outer circle of the shoulder is, the end face of the head is, and the end face of the shoulder is%4.6 The circular runout of the end face of the head to the thread diameter is 0.02mm. 4.7 The surface heat treatment hardness is not less than 450HV45. 4.8 The surface blackening should comply with the provisions of Article 1.11.2 of ZBY17012. 5 Test method
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5.1 The major diameter of the thread SM15/64\×28 is measured with an external micrometer with a graduation value of 0.01mm, and the middle diameter is measured with a thread ring gauge or a thread measuring micrometer with a graduation value of 0.01mm.
5.2 The outer diameter of the head 16mm and the screwdriver slot width 1.5mm are measured with a vernier caliper with a graduation value of 0.02mm. 5.3d9.5mm is measured with a special caliper or an external micrometer with a graduation value of 0.001mm. 5.42.2mm is measured with a special gauge.
5. 5 The surface roughness of the corresponding surface roughness comparison sample is selected for visual comparison. 5.6 The circular runout of the end face C to the middle diameter of the thread is 0.02mm, and the measurement method is shown in Figure 2. Figure 2
a. Screw the thread take-up rod screw into the screw hole of the measuring instrument and tighten it with the end face D. b. Contact one end of the lever with the end face C to be measured, and the other end with the micrometer with a graduation value of 0.001mm; C. Turn the screw to be measured, and the value of the micrometer pointer swing is the circular runout error value of the screw to be measured. 5.7 The determination of heat treatment hardness shall be in accordance with Article 4.2 of ZBY17015. 5.8 The blackening of the surface shall be in accordance with Articles 2.1 to 2.2 of ZBY17012. 6 Inspection rules
6.1 The products leaving the factory must be inspected and qualified by the quality inspection department of the manufacturer, and an inspection certificate shall be attached. 6.2 Inspection classification
Product inspection is divided into two categories: factory inspection and type inspection. 6.2.1 Factory inspection
When the product is delivered, the consignee has the right to accept it according to the factory inspection items specified in this standard. 6.2.2 Type inspection
If any of the following situations occurs, a comprehensive assessment of product quality is required and a type inspection should be conducted. a. After formal production, if there are major changes in structure, materials, or processes that may affect product performance; b. Periodic inspection should be conducted every three months of normal production; c. When there is a significant difference between the factory inspection results and the last type inspection; d. When the superior quality supervision agency proposes a requirement for type inspection. 6.2.3 Product quality characteristics and inspection categories
See Table 1 for product quality characteristics and inspection categories. No.
Inspection items
Butterfly pattern SM15/64\X28
4.2 Head outer circle 16mm
4.2 Screwdriver slot width 1.5mm
4.3 $9.5-8.0o9mm
4.42.2r888mm
Surface roughness
Jumping 0. 02mm
Hardness ≥450HV45
4.8 Surface blackening
6.3 Factory inspection specifications
6.3.1 Sample selection
Samples should be randomly selected from the inspection batch submitted. 6.3.2 Sampling plan and strictness
OB/T 2146.
Classification of quality characteristics
The sampling plan for normal inspection is shown in Table 2. The determination of strictness shall be in accordance with Article 4.6 of GB/T2828. Table 2
Inspection level
Sampling plan
Number of inspection items for sample unit
Qualified quality level (AQL)
Batch range
12013200
3201~10000
10001~～35000
35001~150000
150001~500000
>500001
Sample size
Note: ①The sample unit is each screw.
Sample size
②A and R of Class B are counted as the number of non-conforming products, and A and R of Class C are counted as the number of non-conforming products. 6.3.3 Judgment of qualified or unqualified inspection batch B
Inspection classification
Normal inspection sampling plan
According to the inspection results of the sample, if the number of unqualified products of Class A and Class C found in the sample are both less than or equal to the corresponding qualified judgment number (A.), then the inspection batch is judged to be a qualified batch; if the number of unqualified products of Class B and Class C found in the sample is greater than or equal to the corresponding unqualified judgment number (R), then the inspection batch is judged to be an unqualified batch.
6.3.4 The disposal of unqualified products and batches after inspection shall be in accordance with Article 4.12 of GB/T2828. Www.bzxZ.net
6.4 Type inspection rules
6.4.1 Sample extraction
QB/T 2146-1995
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Samples should be extracted from a batch or batches manufactured in this cycle and passed the factory inspection, and the samples obtained should be guaranteed to represent the manufacturing technology level of this cycle.
6.4.2 Sampling plan
The sub-sampling plan for type inspection is shown in Table 3.
Discrimination level
Sampling plan
Non-conforming prohibited classification
Number of inspection items for sample unit
Non-conforming quality level (RQL)
Sample size
Note: ①The sample size is each screw.
②AR of Class B. Counted as the number of unqualified products, R of Class C is counted as the number of unqualified products. 6.4.3 Judgment of passing or failing type inspection 5
Normal inspection single sampling plan
According to the results of sample inspection, if the number of Class B unqualified products and the number of Class C unqualified products found in the sample are less than or equal to the corresponding qualified judgment number (A), then the batch is judged to be a qualified batch. If one of the number of Class B unqualified products and the number of Class C unqualified products found in the sample is greater than or equal to the corresponding unqualified judgment number (R.), then the batch is judged to be an unqualified batch. 6.4.4 Disposal after type inspection
Disposal after type inspection shall be in accordance with Article 412 of GB/T2829. 7 Marking, packaging, transportation and storage
7.1 Marking
The product packaging shall have the following markings:
a. Product model;
b. Part name or code:
Manufacturer's name,
d. Packing date and quantity:
e. Standard number 3
f. Handle with care, afraid of moisture, upward, the stacking limit diagram shall comply with the provisions of GB191. 7.2 Inner packaging of products
The product is packaged in No. 10 boxboard cartons, which must be lined with polyvinyl fluoride plastic bags, 800 pieces per box. If there are other requirements for the quantity and form of packaging, the supplier and the ordering party can negotiate and decide. 7.3 Packaging, transportation and storage
The packaging, transportation and storage of products shall be in accordance with 7.1~7.2. Additional Notes
This standard was proposed by the Quality and Transportation Standards Department of the China Light Industry Association. This standard is under the jurisdiction of the National Sewing Machine Standardization Center. This standard was drafted by the Shanghai Sewing Machine Screw Factory. The main drafters of this standard are Xu Minghua, Chen Dadong and Zhang Yuexiang. 369
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