How to read fasteners Mill sheet?

    If you are working in manufacturing business, you may have heard of Mill sheet earlier. Even you are a responsible person to deal with Mill sheet or not it would be useful if you can generally know what does each part of mill sheet refer to.

    Today, I will explain what is the mill sheet and how to read it, I may not explain all of the details in the document but will point out the only major points that we are generally use.

    To make it easier to understand, before we started, let’s start from the example thing around our daily life first.

What about coffee, do you drink coffee?

    Do you know that some of good coffee beans are also traceable? We can know the story of them from their document.

    For traceable and reliable coffee beans sources, there will be a label (QR in some cases) on the beans bag to show information such as origin, farm, roasting process, type of beans, taste note, and etc.

    Even coffee beans yet contain so many traceable information for us to explore to increase our excitement and confidence before we consumed, why metal which is a foundation of our modern daily life not?

    Mill sheet is a document that shows the specification of metal regardless of metal type such as steel, stainless steel, Titanium, or Aluminum. Each of metal type will be define their grade such as SWCH, S45C, or SCM435 for steel. XM-7, SUS304, or SUS316L for stainless steel. This document will verify that material as per document are followed with specific standard requirement.

    Mill sheet will be issued from Metal manufacturer only, sometimes third party also involved in mill sheet issuing process as well.

Other calling terms for Mill sheet in another country are;

·         Mill Test Report (MTR)

·         Certified Mill Test Report

·         Certified Material Test Report

·         Mill Certification

·         Mill Inspection Certificate

            This is a document that help you to track back to the origin and characteristics of the material.

            For metal, mill sheet may contain some or all of this following information;

For full scale picture of sample mill sheet, please click here

*Above picture is a sample mill sheet, some of information are erased/edited for demonstration purpose, Thank you for your understanding*

 

·         Material Heat Number/Lot No./Charge No./etc.

o   Other calling term for this section may vary depend on maker

Material Heat No. is like a Metal ID card number, it refers to specific batch of raw material that used in production process

·         Material Grade/Type/Symbol/etc.

This refers to Material category/grade/type of each metal.

“Steel” is a broad calling term for material but it is not specifying which type of steel it is, so this may not state in the mill sheet. For steel it will show as these examples, SWCH10R, SS400, SPCC, SWRH62B, SCM435H, and etc.          

·         Edition Year and Type of Specifications Met

This information mostly shows next to material grade such as JIS G4052 (2016)

Show the standard which to follow to make this material, this information contain method, inspection, and other necessary information to produce the material

·         Material Dimensions/Size/Description/Diameter

This information shows the size of material using for the metal production

Some of the mill sheet may show type of material whether they are Wire rod in Roll, Round bar, flat bar or etc. as well

·         Mechanical Properties

This information shows Mechanical Properties of material such as Yield Strength, Tensile strength, Hardness, and Elongation before they processed to fasteners.

·         Chemical Analysis/Chemical Properties/Chemical Composition

This information shows breakdown of material’s chemical properties, depending on metal type, chemical composition may vary but it must be fall within required range for each standard in this case JIS G4052 (2016)

·         Heat Treatment (if applicable)

In some case, heat treatment process is required for some material for hardness increase purpose. Even hardness increase is needed, some of fasteners maker will operate heat treatment process after raw material processed or machined to be fasteners. So, this information may not write in mill sheet but inspection data of the product instead.

Hardness testing method will be vary depending on material characteristic and they will be stated as HRC, HBW, HV or else.  

·         Company name/Address/Certified Inspector Signature

This section refers to the company that make this material, their address, and the name of a person who made this report and assure the document correction.           

Mostly when we would like to check the origin country of the material, we will check at this section. Company name and their address in the mill sheet represent country of material origin.

Inspector name is erased and edited for demonstration purpose

    Sometime customer requested fasteners with particular origin of material such as Japanese Material only, Non-China Material only, Domestic Material only, and etc.

    If they requested like this, we have to make sure with customer requirement whether imported material but production locally is acceptable or not, or both material origin and manufacturing process must be done within specific country.

    For example, Chinese/Taiwan material (Especially, Stainless Steel series) gain cost competitive in the industry. So, some of manufacturers in Japan are importing material from those countries to produce Stainless Steel fasteners. In this case, fasteners quality might be no problem but some customer yet still concerned about this issue, this could be their technical, political, trade, or personal issue. Then, it is better to know what your customer needed, and confirm all requirement with them to prevent misunderstanding or misinformation.

*If mill sheet is needed, please make sure to let your fasteners maker or distributor know prior before you place the order. Because, fasteners lot number is needed to get mill sheet document* 

    If mill sheet request submitted after product delivered, it may difficult to track back whether this fastener is made from which material batch.


    How was the content? I hope you will get useful information and be able to read or understand basic information of the mill sheet. If you have any inquiry about fasteners with mill sheet needed, please feel free to contact us. We are willing to assist you.   

Written by,

                                                                                                      Mr.Nuttapol Sirilert

                                                                                                 International Sales Team

                                                                                                    Hanshin Neji Co.,Ltd.