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Haiyan Tianqi Fastener Co., Ltd.
  • Add:Jiaxing Haiyan China NO.1-3 Jincheng South road, Qinshan Industrial Zone of Haiyan, Jiaxing
  • Tel:+86-573-86408971
  • Mobile Phone:+86-13606831322
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  • Post Code:314300
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Repair of non-standard screws

2021-05-10

Repair of non-standard screws
① Thread damage, use triangle screw oil stone for cleaning and polishing, and machining if necessary.

② If the hardness exceeds the standard, carry out a metallographic inspection, if necessary, an impact toughness inspection, and use the heat treatment method to recover.

③Analyze the types of cracks. If it is only a surface crack, continue to use after polishing to eliminate the crack, otherwise it should be scrapped.

④The creep value exceeds the standard, and it is judged and processed according to DL439-1991 "Technical Guidelines for High Temperature Fasteners in Thermal Power Plants".

⑤Adjusting bolts are bent. If the bending is small, heat treatment after correction. If the bending is large, spare parts need to be replaced.

⑥ Washer wear or indentation, grinding treatment or replacement of spare parts.

⑦ Female thread is damaged, use taps or machining to repair, replace spare parts if repair is impossible.

⑧The thread of the threaded hole is damaged. Use a tap or machine to repair it. If it cannot be repaired, contact the manufacturer. If necessary, use the method of reaming and tapping and resupply the adjusting bolt. After the hardness of all high-temperature welding nuts and other fasteners are qualified, the adjusting bolts and welding nuts should be renumbered according to the hardness value.

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