Considering the company's wide variety of standard parts and specifications, the large number of warehouses entering and leaving the warehouse, and different user requirements; in order to scientifically carry out quality management, strictly control product quality, and avoid unqualified products from flowing into the hands of customers, we have specially formulated our company's standard parts storage Inspection process.
Product classification
根据标准件的用途以及材料、强度等级的不同，我们把标准件分为A、B、C三大类；A类为关键件、B类为重要件、C类为一般件。A类主要是机械性能等级≥10.9级的螺栓、螺柱和螺钉以及机械性能等级≥10级的螺母；B类主要是机械性能等级为8.8级的螺栓、螺柱和螺钉、机械性能等级8级的螺母以及规格≥φ12的镀锌弹簧垫圈；C类主要是普通螺栓、平垫圈、小规格弹簧垫圈以及其他普通标准件。A、B、C三类产品的检验流程和检验项目分别如下：
Type A key parts
The inspection process and inspection items of Type A key parts are as follows:
90.1. Number of sampling samples: After class A products arrive in the warehouse, the quality inspector shall randomly sample each batch of products in accordance with the national standard GB8 "Provisions for Acceptance and Inspection of Fasteners", and the number of samples per batch is ≥XNUMX A; samples are taken from different packing boxes.
XNUMX. Inspection items:
1. Inspection of the type and size: the width and thickness of the opposite side of the hexagon head of the bolt, the diameter of the hexagon socket head, the thickness of the head; the depth and width of the opposite side of the hexagon socket; the diameter of the bolt, screw, stud, and the length of the bolt , The straightness and coaxiality of the bolt shaft.The width of the opposite sides of the hexagonal nut, the thickness of the nut, the perpendicularity and coaxiality of the nut hole to the supporting surface.Inspection tools: steel tape, vernier caliper, micrometer, flat plate, etc.
2. Thread accuracy inspection: mainly check thread length, thread pass and stop, thread clamping, random buckle and other defects.Inspection tools: vernier calipers, threaded ring gauges, etc.For bolts with galvanized surface or Dacromet treatment, external and internal threads can be inspected with h and H through gauges.
3. Appearance inspection: mainly check the surface roughness, whether there is rust on the surface, whether there are defects such as cracks, burrs, and overburning, and whether there is too much dacromet in the thread.
4. Mechanical performance inspection: The quality inspection report and material certificate provided by the manufacturer should be carefully checked, and the hardness of the bolts and nuts should be checked in accordance with the provisions of the national standards GB3098.1 and GB3098.2.The hardness of bolts, studs and screws should be measured on the rod or thread end; the hardness of the nut should be measured on the supporting surface, and the average value of the three-point hardness at an interval of 120 degrees should be taken as the hardness value of the nut.When there is a deviation between the inspection result of the surface hardness and the manufacturer's quality inspection report, the core hardness should be re-checked and the core hardness shall prevail.
For bolts with diameter ≥ M12 and strength grade ≥ 10.9, 2 to 3 specifications should be sent to a qualified third party for tensile strength test every month. For turntable connecting bolts, the chemical of the bolt material should be outsourced from time to time. ingredient.
For nuts with diameter ≥ M12 and strength grade ≥ 10, 1 to 2 specifications should be sent to a qualified third party for guaranteed load test every month.
Class B important parts
Inspection process and inspection items of B-class important parts:
90.1. Number of sampling samples: After class B products arrive at the warehouse, the quality inspector should randomly sample each batch of products in accordance with the national standard GB8 "Provisions for Acceptance and Inspection of Fasteners", with the number of samples per batch ≥ XNUMX; The samples were taken from different packaging boxes.
XNUMX. Inspection items:
1. Inspection of the type and size: the width and thickness of the opposite side of the hexagon head of the bolt, the diameter of the hexagon socket head, the thickness of the head; the depth and width of the opposite side of the hexagon socket; the diameter of the bolt, screw, stud, and the length of the bolt , The straightness and concentricity of the bolt shaft.The width of the opposite sides of the hexagon nut, the thickness of the nut, the verticality and coaxiality of the nut hole.Inspection tools: steel tape, vernier caliper, micrometer, flat plate, etc.
2. Thread accuracy inspection: mainly check thread length, thread pass and stop, thread clamping, random buckle and other defects.Inspection tools: vernier calipers, threaded ring gauges, etc.For bolts with galvanized surface or Dacromet treatment, external and internal threads can be inspected with h and H through gauges.
3. Appearance inspection: mainly check the surface roughness, whether there is rust on the surface, whether there are defects such as cracks, burrs, and overburning, and whether there is too much dacromet in the thread.
4. Mechanical performance inspection: The quality inspection report and material certificate provided by the manufacturer should be carefully checked, and the hardness of bolts and nuts should be checked in accordance with the national standards GB3098.1 and GB3098.2; when the surface hardness inspection results deviate from the manufacturer’s inspection report, the Recheck the core hardness and take the core hardness as the standard.
对直径≥M20的8.8级螺栓和8级螺母，应每月送1~2个规格到有资质的第三方做抗拉强度试验和保证载荷试验。
5. For galvanized spring washers with specifications ≥ 12, each batch shall be sampled for hydrogen embrittlement test and toughness test in accordance with the provisions of the national standard GB94.1, the number of tests is 8 each.
Class C general parts
The inspection process and inspection items of C general parts:
90.1. Sampling sample number: After class C products arrive in the warehouse, the quality inspector should randomly sample each batch of products in accordance with the national standard GB8 "Provisions for Acceptance and Inspection of Fasteners", and the number of samples for each batch is XNUMX; Samples should be taken from different packaging boxes.
XNUMX. Inspection items:
1. Inspection of the type and size: the width and thickness of the opposite side of the hexagon head of the bolt, the diameter of the hexagon socket head, the thickness of the head; the depth and width of the opposite side of the hexagon socket; the diameter of the bolt, screw, stud, and the length of the bolt , The straightness and concentricity of the bolt shaft.The width of the opposite sides of the hexagon nut, the thickness of the nut, the coaxiality and symmetry of the nut hole.Check the inner diameter, outer diameter, thickness, and diameter of the retaining ring of the retaining ring.The basic dimensions of other standard parts.
(Inspection tools: steel tape, vernier caliper, micrometer, plate, etc.)
2. Thread accuracy inspection: mainly check thread length, thread diameter, thread clamping, random buckle and other defects. (Inspection tools: vernier caliper, micrometer ring gauge, plug gauge, etc.)
3. Appearance inspection: mainly check the surface roughness, whether there is rust on the surface, whether there are cracks, burrs, overburn and other defects.
Note*: The quality inspection standards are in accordance with the relevant standards and product standards of the "Fastener Basic Volume". If the mechanical performance of Category A and B products fail to pass the random inspection, they should be sealed up immediately and marked and reported to the company’s planning department and company leaders.For products with a small number of general defects, after reporting to the planning department and company leaders for approval, all products can be sorted or returned for repair. (This process is used as the quality inspection guide for all warehouses and special warehouses within the company. If problems are found, they can be modified and improved.)
Zhengzhou Ever-Power Co., Ltd. produces wholesale customized standard parts, fasteners, various specifications of bolts, nuts, valve stems, worm gear boxes, bevel gear boxes, etc. For details, please refer to the company’s official website http://www.worm-gearbox. xyz/