Inspection Standards for Shuttering Magnet

The Testing Standards Are Stipulated As Follows:

1. Scope:

This standard specifies the material requirements, inspection methods, testing methods, packaging, transportation, storage, and quality inspection requirements for shuttering magnets.

This standard applies to shuttering magnets manufactured using neodymium-iron-boron (NdFeB) permanent magnet production processes.

2. Terms and Definitions:

The terms and definitions specified in GB/T 13560-2017, together with the following terms and definitions, apply to this document.
2.1 Main Magnetic Properties

The main magnetic properties include:
Residual magnetic flux density (Br)
Intrinsic coercivity (Hcj)
Magnetic induction coercivity (HcB)
Maximum energy product ((BH)max)
2.2 Main Holding Force
The main holding forces include:
Magnet holding force (KG)
Shuttering magnet holding force (KG)
2.3 Maximum Operating Temperature
The heat resistance temperature of NdFeB permanent magnetic materials varies according to the magnet grade.
For N-series magnets, after assembly in the shuttering magnet, the maximum operating temperature shall be below 80 °C.

3. Model

3.1 Model Classification

Shuttering magnets are classified according to their holding force, and each specification has a different magnetic holding force.

For example, "GME-1000" signifies the following: "GME" represents the company abbreviation, while "1000" denotes the magnetic suction force-specifically, that the magnetic suction force reaches 1000 kg.

4. Dimensions

The main dimensions of the shuttering magnet shall comply with the requirements of the specification of the shuttering magnet. (If the purchaser has special requirements, the supplier and purchaser may negotiate separately.)

4.1 The auxiliary magnetic performance of the shuttering magnet is for design reference only and shall not be used as the basis for acceptance inspection or rejection.
4.2 The surface of the product shall not contain defects that may affect its use, such as cracks, sand holes, inclusions, burrs, or edge and corner peeling.
4.3 The vertical magnetic pull force of the internal magnet core shall exceed the specified parameter requirement by more than 1%.
For example, for a 1000 kg magnet specification, the actual vertical pull force of the magnet core shall reach at least 1010 kg.
4.4 The overall vertical magnetic pull force of the finished shuttering magnet shall 100% meet the specified parameter requirements.
For example, for a 1000 kg shuttering magnet, the overall vertical pull force of the assembled magnet box shall reach 1000 kg.
4.5 The front structure of the shuttering magnet housing shall be equipped with reinforced plates to prevent deformation caused by external impacts.
The internal reinforcement structure shall use 6 mm-thick steel plates to enhance the internal strength of the housing.
A snap-fit design shall be adopted between the housing components to increase the connection strength between parts. This design also improves the welding strength at vulnerable areas and extends the service life of the housing.

4.6 The stability of the structure and magnetic holding force of the shuttering magnet mainly depends on the flatness of the contact surface between the magnet core and the casting table (steel platform).

The surface of the magnet core must be ground using a precision grinding machine, and the flatness tolerance during machining shall be within 0.02 mm.

During assembly, a stainless steel spacer block shall be installed between the magnet core and the magnetic switch in order to increase the contact area between the magnet core and the magnetic switch. This prevents internal unevenness of the magnet core during the switching operation of the shuttering magnet and avoids a reduction in the magnetic holding force. As shown:

4.7 During the assembly process of the magnet and square steel components, a stainless steel ring shall be added to protect the magnet.

The steel ring shall be made of SUS304 stainless steel, with a thickness of 0.5 mm, as shown in the figure below.

4.8 During the assembly of the magnet and square steel components, it shall be ensured that the magnet has no cracks or obvious chipping.

Magnets with chipped corners exceeding 1 mm × 1 mm × 1 mm shall not be used.

After assembly, the surface of the square steel component shall be 0.8 mm higher than the surface of the magnet, so that during operation the square steel contacts the casting platform first, thereby protecting the magnet.

4.9 During the assembly of the magnetic core and housing, high-strength grade 12.9 bolts shall be used.

Recommended brand: Taiwan Anchor Fasteners.

4.10 At the joint positions of the housing, fixing screws shall be used together with the assembly, and high-strength grade 12.9 bolts shall be adopted.

Picture	Item	Inspection Item	Technical Requirements	Inspection Method
	Shelling	Appearance	• Iron parts shall undergo blackening (spray) surface treatment; stainless-steel parts shall have polished surfaces without visible grinding marks. • Surface shall be smooth, clean, dry, rust-free, burr-free. • Welded areas shall match the approved sample, with no weld spatter, cracks, pores, or visible deformation. • Product bottom shall be flat; when placed on a platform, it shall not wobble. • Surfaces shall be even; the weld joint between iron and aluminum parts shall have no gaps. • Dimensions D1 and D2 must be consistent. • All product accessories must be complete and free of defects.	Visual inspection / Caliper
		Dimensions	Must comply with the drawing specifications.	Caliper measurement
		Compatibility	The product shall properly match the corresponding switch head and magnet block, without jamming, looseness, or excessive clearance.	Visual inspection / Manual check
	Switch Head	Appearance	• Product surface shall be smooth and clean; blackened (oxide) coating must be complete and uniform. • No rust; stainless-steel surfaces shall be polished without defects. • Surface shall be free from burrs, scratches, dents, or damage. • Circle edges shall be uniform; surface A shall be flat and free of deformation.	Visual inspection
		Dimensions	Must comply with drawing specifications.	Caliper measurement
		Compatibility	Must properly fit with the nylon cap assembly to prevent the nylon cap from detaching.	Manual check
	Square Steel Assembly	Appearance	• Surface shall be smooth, clean, and free of rust. • Surface shall have no burrs or scratches. • Deformation of each long and short side shall be inspected; maximum deviation shall not exceed 0.4 mm. • Top and bottom surfaces shall make full and even contact with the grinding platform. • The magnetic force surface shall have no dents.	Visual inspection, Caliper measurement
		Dimensions	Must comply with drawing specifications.	Caliper measurement
		Flatness	The top and bottom surfaces of the magnet block shall be as flat as steel plates. Flatness tolerance: ±0.05 mm.	Square ruler Caliper measurement

Test Report of Shuttering Magnet

5. Testing Equipment

When testing the magnetic attraction force, a dedicated tensile testing machine should be used, and the test should be performed at a speed of 3mm~5mm/min, as shown in the figure below:

5.1 Magnetic Flux Testing

The magnetic flux Gs of a magnet shall be tested according to the magnet performance standards, as shown in the following figure:

5.2 Outer Shell Material Inspection

The iron casing shall be fabricated from high-strength steel plate, possessing a strength at least 1.5 times that of standard Q235 steel plate; its thickness shall be uniform, with a tolerance controlled within 0.05 mm. The stainless steel casing shall be fabricated from SUS201 steel plate; its thickness shall be uniform, with a tolerance controlled within 0.05 mm.

6. Inspection Rules

6.1 Inspection and Acceptance

6.1.1 The supplier's quality inspection department shall inspect the products to ensure that the materials conform to the requirements of this standard and complete an inspection report.
6.1.2 The purchaser shall inspect the received products according to the requirements of this standard. If the inspection results do not conform to the requirements of this standard, the purchaser shall notify the supplier within one month from the date of receipt of the products, and the two parties shall negotiate a solution.

6.2 Inspection Items

Each batch of products will be inspected for main magnetic core performance, dimensional deviations, appearance quality, or items specified in the contract.

6.3 Inspection Result Judgment

6.3.1 If the product's appearance quality inspection result is unqualified, the product will be judged as unqualified. However, individual inspection is allowed, and qualified products will be delivered.
6.3.2 If any of the main magnetic attraction performance or dimensional deviation inspection results are unqualified, double the sample size will be taken from the batch for repeated inspection of the unqualified item. If there are still unqualified items, the batch of products will be judged as unqualified.

7. Marking, Packaging, Transportation, and Storage

7.1 Marking and Packaging

7.1.1 Products are generally delivered in the condition required by the vertical magnetic core attraction. If the buyer requires different magnetic attraction forces, the required specifications can be specified in the contract.
7.1.2 Products are packaged in cardboard boxes and guaranteed not to be damaged during transportation and storage. Each package should be labeled or marked with:

a) Supplier name

b) Product model

c) Quantity

d) Date of manufacture

7.2 Transportation and Storage

Products should be handled with care during transportation and stored in a well-ventilated, dry place free from corrosive atmospheres.

7.3 Inspection Report

Each batch of products should be accompanied by a quality inspection report, indicating:
a)Supplier name)
b)Product name and specifications)
c)Inspection results and the supplier's quality and technical inspection department's stamp
d) Inspection date) Date of manufacture

e) Date of Manufacture