China Forging Knife Industry Standard

Occupation Standard

Dazu forging knives are an industry standard for metal forging knives jointly issued by relevant institutions and enterprises in Chongqing in November, 2020. It is suitable for the production of forging knives with blades made of metal materials, covering terminology definition, product classification and technical requirements.

 

The standard was jointly drafted by more than ten enterprises including Chongqing Hardware Quality Inspection Center, Dazu Hardware Chamber of Commerce and Deng's Kitchenware, and stipulated the hygiene and safety, material selection, appearance quality and performance indicators, such as the angle range of the blade, quenching width, hardness grade and contact with food parts, which should meet the food safety standards.

The standard specifies that the blade must be made of carbon steel or stainless steel, the handle must pass the drop test, the gap between components should not exceed 0.3mm, and the sharpness of the chef knife should be ≥ 30mm. Its technical specification integrates the traditional forging technology in Dazu area, covering five types of knives, such as bone cutting and chopping, and is promoted through anti-counterfeiting identification and public testing platform.

 

This standard was formulated by Dazu Hardware Chamber of Commerce in half a year to cope with the uneven quality of the industry and the pressure of external competition, and was registered as a national certification trademark in 2021. After the implementation of the standards, more than 40 enterprises were promoted to upgrade their technology, and the compilation of standards for follow-up groups such as "Hand Saw" was promoted to help the standardized development of the regional hardware industry.

 

Requirements

 

5.1 Hygienic Requirements

The metal part of the tool in contact with food should comply with GB 4806.9. Non-metallic parts of knives in contact with food shall conform to the provisions of the corresponding national food safety standards.

 

5.2 Materials

5.2.1 General Rules

The knife shall be made of materials that can ensure that its finished product meets all the performance requirements of this document, and the cutting knife shall not contain any components that are harmful to health or have adverse effects on any organic tissues under the foreseeable use conditions.

 

5.2.2 Blade Materials

Blade materials shall comply with the provisions of GB/T 699 and GB/T 4237 texts or the provisions of current standards of corresponding brands that meet the requirements of this document.

5.2.3 Knife Handle Material

The handle shall be made of metal, plastic, wood-plastic composite pressure plate, impregnated wood or other materials, so as to make the finished handle meet the requirements in 5.11 of this document.

5.3 Appearance

5.3.1 Assembly Cooperation

The assembly of each component of the cutter should be firm and safe, and the components should not be loose. Except for special design requirements, the clearance of each component of the tool should not exceed 0.3 mm 5.3.2 Blade Appearance

5.3.2.1

The appearance of blade should be smooth, free of dirt, rust, burr and other defects. The main surface should be bright and consistent, and the patterns and trademarks should be clear and complete and in the same position.

5.3.2.2

The edge of the blade should be smooth, and the inner edge should be free of Mao Kou.

5.3.2.3

Except for special design requirements, the blade should be straight and symmetrical, without obvious bending, with a straight edge and back, and a "V" shape from the edge to the back.

5.3.2.4

The blade edge of composite steel blade is not allowed to have partial steel, the exposed steel width is not less than 0.2 mm, and the blade edge should not have defects such as overburning, fracture and inclusion. The cumulative length of polished coarse wire and black wire below 10 mm on the blade body should not exceed 50 mm, and the number of pits within 1 mm2 should not exceed 5.

5.3.2.5

Stainless steel blades should have no obvious defects, coarse grinding wheel wires and black wires. There should be no defects with a diameter of more than 0.3 mm and indentations with a diameter of more than 0.8 mm on the surface of each blade.

There should be no more than two defects and indentations that do not exceed this limit in every 10 cm2 area, and the distance between any indentation and defect should not be less than 20 mm

5.3.3 Appearance Of Hilt

The surface of the handle should be clean and tidy, without burrs, pores and cracks.

5.3.4 Surface Roughness

5.3.4.1

The main body of the cutter body is carbon steel cutter blade surface roughness Ra≤3.2 μm m.

5.3.4.2

The main body of the blade is stainless steel, and the blade surface roughness Ra is less than or equal to 1.6 μ m.

5.4 Knife Wrap Angle

5.4.1 Angle of cutting edge Except for bone cutting knives, chopping tools and tools with special design requirements, the blade angle of kitchen knives and other knives should not be greater than 40.

5.4.2 Blade Thickness

Except for bone cutting knives and blades with special design requirements, the thickness of cutting knives 1 mm away from the cutting edge should not be greater than 1.2 mm, and the thickness of slicing knives and other knifeware 1 mm away from the cutting edge should not be greater than 0.6 mm.

5.5 Sharpness And Durability

The sharpness And Durability of cutting knives shall meet the requirements in Table 2. Table 1 Sharpness And Durability

Project Index

Chef Knife Cleaver Knife

Knife Sharpness, mm ≥30 ≥20

Durability, mm ≥110 ≥80

Note: Bone cutting knife and other knives are not required.

5.6 Hardness

The hardness of stainless steel cutters and alloy steel cutters shall be not less than 50 HRC, and that of carbon steel cutters shall be not less than 52 HRC. The hardness difference between any two points on the same material of each cutter shall be not more than 3 HRC.

5.7 Quenching Width

The blades of stainless steel blades and alloy steel knives are completely quenched, and the width of quenched blades of carbon steel kitchen knives and composite knives should be no less than 20 mm.

5.8 Metallographic Structure

5.8.1

The material of the blade is carbon steel, and its metallographic structure is tempered martensite (lower bainite is allowed), and the martensite level is not greater than Grade 4.

5.8.2

The material of the blade is stainless steel, and its metallographic structure is tempered martensite (lower bainite is allowed)+finely distributed carbide+a small amount of retained austenite.

5.9 Corrosion Resistance

Stainless steel cutters and composite stainless steel kitchen knives should have good corrosion resistance. Stainless steel materials shall reach protection level 6 and above.

5.10 Drop Resistance

After the test according to 6.10, the handle should not be loose or broken, and the blade should not be cracked or broken.

5.11 Handle

5.11.1 Strength Of Handle

After the test according to 6.11.1, the handle should be free from looseness and deformation.

5.11.2 Connection Firmness Of Knife handle

According to the method specified in 6.11.2, the handle of non-integral structure should not be loose.

5.11.3 Welding And Assembly

The welding place between the metal handle and the blade should be smooth and free of air holes and burrs. Knife hoop and washer should be assembled tightly, firmly and correctly.

5.11.4 Water Deepage Resistance Of Hollow Handle

According to the test in 6.11.4, the hollow handle and its connecting parts should not leak water.

5.11.5 Thermal Deformation Resistance Of Nonmetallic Knife Holder

After the test according to 6.11.5, there should be no obvious deformation of the nonmetal handle except ceramics, and the gap between metal and nonmetal should not exceed 0.4 mm.

5.11.6 Environmental Stress Resistance Of Plastic Handle

After the test according to 6.11.6, there should be no crack in the handle.