Heat treating and inspection of metals Page: 50

TM 1-423
47 AIR CORPS
will be interrupted and the strongest indication of a given defect
will be shown. The failure to obtain flux lines other than parallel
to the defects may result in failure to locate them. It'lollows, there-
fore, that parts should be magnetized in several directions and the
powder applied after each magnetization, as a second magnetization

4L

I ri4 J
0

/
ksy

1. Large unit. 2. Small unit.
FIGURE 10.-Demagnetizing apparatus.

tends to neutralize the first. Parts to be inspected should be free
of grease, loose grit, and dirt. Paint, lacquer, plating, and other
protective coatings, if dry, need not be removed.
b. Magnetizing methods may be divided into two general groups:
the residual method, and the continuous method.
(1) In the residual method of magnetization, the residual mag-
netism of the material being inspected is relied upon to attract the
particles. The residual magnetism is imparted to the object by means
of an initial charge induced by the magnetizing apparatus. This
method is not considered as sensitive as the continuous method al-
though it may be used to produce satisfactory results in many cases.

Upcoming Pages

Here’s what’s next.

upcoming item: 53 53 of 72
upcoming item: 54 54 of 72
upcoming item: 55 55 of 72
upcoming item: 56 56 of 72

Show all pages in this book.

This book can be searched. Note: Results may vary based on the legibility of text within the document.

Citing and Sharing

Basic information for referencing this web page. We also provide extended guidance on usage rights, references, copying or embedding.

Reference the current page of this Book.

United States. War Department. Heat treating and inspection of metals, book, September 10, 1941; Washington D.C.. (digital.library.unt.edu/ark:/67531/metadc96657/m1/52/ocr/: accessed June 24, 2017), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.