[modeleng] Re: Free Cutting Steel

  • From: "Ron Head" <ron.head@xxxxxxxxxxxxx>
  • To: <modeleng@xxxxxxxxxxxxx>
  • Date: Fri, 28 Oct 2005 19:06:57 +0100

Hi Roger

The reason for the controversy over weldability, is that not all 
free-cutting steels contain lead!  A free-cutting steel has a high sulphur 
content to improve the machinability, at the expense of a reduction in 
tensile strength and ductility.  Lead can also be added to give an increased 
tool life.  The confusion arises from the fact that (here in the UK) BS 970 
doesn’t specify any lead content at all, hence any added lead is at the 
steel supplier’s discretion.  The leaded version was sometimes referred to 
as En1APb, but nowadays it is all 230M07 regardless of lead content.

Macready’s list both 230M07 unleaded ("Usaspeed", colour code green) and 
230M07 leaded ("Usaled", colour code magenta).  The main advantage of 
free-cutting steels in industry is that skip loads of curly swarf are 
replaced by a few bins of small chips.  I would suggest that for our work, 
they are largely irrelevant.

As we have no way of knowing the lead content of free-cutting steels bought 
over the counter, the best advice regarding welding is – don’t even try it! 
I tried once and got into a terrible mess.  Silver soldering is a different 
matter, and I've had no trouble in this respect.


Ron Head


----- Original Message ----- 
From: "Roger Mason" <roger.g3tdm@xxxxxxxxxx>
To: "Model Engineering List - Latest" <modeleng@xxxxxxxxxxxxx>
Sent: Thursday, October 27, 2005 8:10 PM
Subject: [modeleng] Free Cutting Steel

>.........I said to the seller that I had recently
> seen reference to the fact that this steel could not be welded.   I
> asked if this extended to silver soldering - could this steel be silver
> soldered?
>     The seller (perhaps to protect his products) said that he regularly
> welded this material and I was silly for suggesting such a thing.
>    At this moment another by-stander,  who had obviously been listening
> said that it was impossible to weld EN1A. 

To UNSUBSCRIBE from this list, send a blank email to, 
modeleng-request@xxxxxxxxxxxxx with the word "unsubscribe" in the subject line.

Other related posts: