• The Biplane Forum is a large global active community of biplane builders, owners and pilots. From Pitts to Skybolts, to older barnstormers, all types are welcome. In addition to our active community, our content boasts exhaustive technical information which is often sought after for projects and maintenance. This information has accumulated over the 12+ years the forum has been in existence.

    The Biplane Forum is a private community. Subscriptions are only $49.99/year or $6.99/month to gain access to this great community and unmatched source of information not found anywhere else on the web. We are also a great resource for non biplane users, since many GA aircraft are built the same way (fabric and tube construction).

Questionable 4130

Skybolt205WD

Well-Known Member
*
Joined
Aug 29, 2006
Messages
761
Reaction score
74
Recently I ordered and picked up from a well known and local Experimental aircraft parts supplier 1 inch x .035 wall 4130. I did not pay attention at the time I picked it up, but when I got to working with it, I noticed that there was none of that white or yellow writing verifying its size and grade. I didnt think much of it until I began to remove the mill scale when I found pitting over the outside surface, I would estimate .0005 or better deep. 80 grit emery cloth would not readily remove it. Today, I stopped by the same store and mentioned the what I had found and was told that was probably some Chinese steel. He then went in back and came out with some 3/8 "4130" that a customer had returned that still had the open seam over about a 12 inch length.
I am not sure what is going on or even if there should be a concern over what I have seen with my last purchase. Has anyone seen this before? Anyone talking about chinese 4130? I dont want to start a panic, so this is more inquiry than statement of fact.
D
 

Latest posts

Top