Exhibit 99.1

JOINT FILING AGREEMENT

In accordance with Rule 13d-1(k)(1)(iii) under the Securities Exchange Act of 1934, as amended, the persons named below agree to the joint filing on behalf of each of them of a Statement on Schedule 13D (including amendments thereto) with respect to the Common Stock, $0.01 par value, of A. M. Castle & Co.  This Joint Filing Agreement shall be filed as an Exhibit to such Statement.

Dated:  September 6, 2016	Raging Capital Master Fund, Ltd.
	By:	Raging Capital Management, LLC Investment Manager
	By:	/s/ Frederick C. Wasch
		Name:	Frederick C. Wasch
		Title:	Chief Financial Officer

Raging Capital Management, LLC
By:	/s/ Frederick C. Wasch
	Name:	Frederick C. Wasch
	Title:	Chief Financial Officer

/s/ Frederick C. Wasch

Frederick C. Wasch, as attorney-in-fact for William C. Martin

/s/ Kenneth H. Traub

Kenneth H. Traub

/s/ Allan J. Young

Allan J. Young