Author Topic: EN8 problems  (Read 8615 times)

Offline jadge

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Re: EN8 problems
« Reply #15 on: October 29, 2020, 03:01:03 PM »
I can't see anywhere on p29 where it mentions leaded EN8?

Basically EN8 comes in three grades; EN8, EN8D and EN8DM. Basic EN8 is what it says it is on the tin. Moving on to EN8D it is slightly harder wearing; the carbon and manganese content is limited to upper end of the ranges specified for EN8. There is a free machining version, EN8DM, but it contains a bit more sulphur (about 0.2%) and a little more manganese. Lead doesn't come into it.

I have stock of all three variants, but haven't done any comparative machining trials.

Andrew

Offline Jasonb

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Re: EN8 problems
« Reply #16 on: October 29, 2020, 03:24:45 PM »
They have several diameters listed twice, one with "Pb" after it the other without. never heard mention of a leaded (Pb) version before
« Last Edit: October 29, 2020, 03:32:00 PM by Jasonb »

Offline jadge

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Re: EN8 problems
« Reply #17 on: October 29, 2020, 03:45:17 PM »
So they do, but I'm not convinced. None of the EN8 specs I checked even listed lead content. They don't mention the BS970 designation for the free cutting version of EN8 either. But I don't have a problem machining EN8 so it's not something I'm going to worry about.  :)

Andrew

Offline bent

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Re: EN8 problems
« Reply #18 on: October 29, 2020, 06:06:54 PM »
Regarding welding 1045 or EN8, the higher carbon content (near .5%) means you need to preheat the weld to about 600F or higher, and maintain that temperature until welding is finished, then slow cool to room temperature.  Use low hydrogen rod or Tig process.  The preheat is to avoid cracking.  If you need all the original strength of the parent metal, you would re-heat treat the part after welding (i.e. at minimum a stress relief).

There's a pretty good description of the home shop process here, including the use of a charcoal fire for the post weld stress relief treatment:
https://app.aws.org/forum/topic_show.pl?tid=34069

 

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