Demagnetising drilling tubulars

We recently had a magnetically "Hot" mud motor and sent it to the shop for degaussing.
The tool was stripped to its component parts and run through the degaussing coil - a check showed residual magnetism had reduced to acceptable levels.
However, 3 days later the parts were again checked and found to be heavily magnetised once again.
Does steel have a "magnetic memory" and if so how can we erase that memory??

2 Answer(s)

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