Why are the kees of a keensert magnetic, although they are made of stainless steel 303?

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The properties of stainless steel develop a magnetic response when cold worked.
also the keenserts, kees are made of 302 instead of 303
the kees are CRES 302.
The cold deformation makes them magnetic. The bodies are not magnetic as they are milled.

 

since the kees of the keensert are cold worked, they change properties and become magnetic.

if you want less magnetic properties, consider using clinserts, there the clins are less magnetic then the kees of the keensert as the clins are made also of 303 stainless steel

 

Even although wrought austenitic stainless steels are non-magnetic in the annealed condition they may develop magnetic response when cold worked. Cold work can transform some austenite to martensite.

stainless keensert clinsert 303 magnetic change kees clins

 

This has a dramatic effect on tensile strength and even more so on yield strength; a heavily cold drawn grade 304 wire can achieve a tensile strength of up to around 2000MPa. Such a highly worked 304 will also be very strongly attracted to a magnet.

Grades with higher amounts of austenite forming elements – nickel, manganese, carbon, copper and nitrogen – form less martensite when cold worked, so do not become so strongly magnetic. This can be evaluated as the ratio of austenite former elements divided by ferrite former elements, or simply as the Ni/Cr ratio. Grade 316 products usually only become slightly magnetic and 310 and 904L are almost totally non-magnetic no matter how severely cold worked. Grade 301 on the other hand has a lesser amount of nickel and work hardens even more rapidly than does 304 …. and becomes strongly magnetic after even a small amount of cold work.

These comparisons are shown in the graph above. Note that different heats of steels of the same grade may exhibit different magnetic responses because of minor differences in the amounts of each element.

 

The magnet are only attracted to the "legs" of the keensert while the body of the keensert is non-magnetic.

translated it means: the legs are the clins of the clinsert.

 

For more info in the different types of stainless steel visit

https://anemo.eu/stainless-steel-comparison

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