13D Filing: Lone Star Value Management and Superior Drilling Products Inc. (SDPI)

UNITED STATES

SECURITIES AND EXCHANGE
COMMISSION

Washington, D.C. 20549

SCHEDULE 13D

(Rule 13d-101)

INFORMATION TO BE INCLUDED
IN STATEMENTS FILED PURSUANT

TO § 240.13d-1(a)
AND AMENDMENTS THERETO FILED PURSUANT TO

§ 240.13d-2(a)

(Amendment No. 2)¹

Superior Drilling Products, Inc.

(Name
of Issuer)

Common Stock,
par value $0.001 per share

(Title of Class of Securities)

868153107

(CUSIP Number)

jeffrey
E. eberwein

lone
star value management, LLC

53 Forest Avenue, 1^st Floor

Old Greenwich, Connecticut 06870

(203) 489-9500

STEVE
WOLOSKY, ESQ.

OLSHAN
FROME WOLOSKY LLP

1325
Avenue of the Americas

New
York, New York 10019

(212)
451-2300

(Name, Address and Telephone Number of Person

Authorized to Receive Notices
and Communications)

June 1, 2017

(Date of Event Which Requires
Filing of This Statement)

If
the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule
13D, and is filing this schedule because of §§ 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following
box ¨.

Note:  Schedules
filed in paper format shall include a signed original and five copies of the schedule, including all exhibits.  See
§ 240.13d-7 for other parties to whom copies are to be sent.

1
The remainder of this cover page shall be filled out for a reporting person’s initial filing on this form with respect to
the subject class of securities, and for any subsequent amendment containing information which would alter disclosures provided
in a prior cover page.

The information required
on the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities
Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject
to all other provisions of the Act (however, see the Notes).

The following constitutes
Amendment No. 2 to the Schedule 13D filed by the undersigned (“Amendment No. 2”). This Amendment No. 2 amends the Schedule
13D as specifically set forth herein.

Item 3 is hereby amended
and restated to read as follows:

The Shares purchased
by Lone Star Value Investors were purchased with working capital (which may, at any given time, include margin loans made by brokerage
firms in the ordinary course of business) in open market purchases, except as otherwise noted, as set forth in Schedule A, which
is incorporated by reference herein. The aggregate purchase price of the 1,689,400 Shares beneficially owned by Lone Star Value
Investors is approximately $1,858,340, including brokerage commissions.

Items 5(a)-(c)
are hereby amended and restated to read as follows:

The aggregate percentage
of Shares reported owned by each person named herein is based upon 24,197,148 Shares outstanding as of May 11, 2017, which is the
total number of Shares reported outstanding in the Issuer’s Form 10-Q filed with the Securities and Exchange Commission on
May 15, 2017.

Percentage: Approximately 7.0%

Percentage: 0%

Percentage: Approximately 7.0%

Percentage: Approximately 7.0%

Percentage: Approximately 7.0%

SIGNATURES

After reasonable inquiry
and to the best of his knowledge and belief, each of the undersigned certifies that the information set forth in this statement
is true, complete and correct.

Dated: June 5, 2017

SCHEDULE A

Transactions in the Securities
of the Issuer since the filing of Amendment No. 1 to the Schedule 13D

LONE STAR VALUE INVESTORS, LP

LONE STAR VALUE MANAGEMENT, LLC

(Through the Separately Managed Account)