Plastic mould Core Pin bent and break, How to choose steel【NO.1170 Daily】

Which type of mold steel is best for plastic molds core pins, provide high strength and high toughness? This is the question what Mr. Li asked me.【誉辉模具钢黄子鹏日记第1170篇】

Mr. Li manufactures injection mould for medical products, one of the core pin, with the narrowest part being 0.4 mm wide. 

Before, H13 steel (40-42HRC) was used for this core pin, but it bent easily under pressure, which meant the interior of the product is filled. 

Later, Mr. Li started using CALMAX steel (54-56HRC). However, sometimes the core pin was damaged by impacts when the mould closed. So Mr. Li asked for suggestions for a better mold steel.

Mr. Li works at a foreign-invested enterprise in China. All the mould steel used there is imported from ASSAB.

Mr. Li also tell me the inject plastic is soft ,that does not have any glass fibre in it. 

Because the core pin is too thin, so it don't have enough strength ,and easy to bend or shift when there's pressure on its.

H13 is a popular tool steel that is often used for making plastic moulds. It is typically hardened to 48-52HRC for use. The H13 used by Mr. Li was not hard enough, so it was more prone to plastic deformation.

Another option, CALMAX, is not very popular in China. CALMAX is a mid-alloy tool steel with 0.6% carbon content, offering higher strength than H13 and capable of being hardened to HRC 52-59. 

The problem with CALMAX is lack of toughness and breaks easily when it hits something. So I suggest that Mr Li use our Yuhui LG mold steel.

LG mold steel offers superior impact toughness, 9 times higher than DC53. It can be hardened to 54-58HRC, maintaining high strength while producing thin-wall molds with excellent toughness. 

LG steel is produced using atmosphere-protected electroslag remelting equipment and six-sided forging, ensuring high purity  and resistance to fatigue cracking with excellent toughness in all directions. 

In 2023, Mr. Song from Wenzhou had a similar problem. He was manufacturing molds for connector products, inject plastic PA66 contain 30% glass fiber. 

This injection mould had 20 core pins, each 0.5mm in diameter, which were inserted into the mold cavities after clamping. 

Previously, Mr. Song used UNIMAX mold steel with 54-56HRC. The core pins would break before reaching normal wear limits. 

If lower the mold steel hardness caused the core pins to wobble during injecting, leading to dimensional variations in the injection-molded parts. 

In this time, I suggested MR. Song to try our Yuhui LG mold steel. In November, I custom-ordered one 100*60*40mm LG mold steel for him. 

By January of the following year, Mr. Song informed me that, the validation results were excellent, and he was highly satisfied. 

He planned to purchase 3 LG mold steel blocks, in 250x200x40mm ,for implementation across other similar molds. 

Until this day, Mr. Song has consistently procured Yuhui LG mold steel for 3 years. We sincerely appreciate his trust and support.

I am Huang Zipeng， from Dongguan Yuhui Mold Steel. More than 3 Fortune 500 companies are using our Yuhui mold steel. Providing genuine mold steel, is our unquestionable guarantee.

This is my No.1169 mold steel diary. For the last 5 years, I've shared my daily work experiences on domestic and international network. 

This also serves as a pledge to my clients: I sell mold steel with sincerity every day. I never offline, and I absolutely will not sell counterfeit or substandard materials to you. Please rest assured.

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#Plasticmould #corepins #LG模具钢 #CALMAX #toolsteel #注塑模具 #镶件弯曲断裂 #H13 #UNIMAX