DTH Tools for Mining · Water Well · Construction · Oil & Gas - Call 877-473-2299

DTH Equipment for the 21st Century and beyond



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Rock-Tech International
12617 E. FM 917, Ste A
Alvarado, TX 76009 USA
Email: sales

Phone: (817) 473-0500
Fax: (817) 473-0504

Staff email:
Judy Herndon
David Griffin
Sean Griffin
Scott Griffin

Rock-Tech International, LLC BBB Business Review
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texas groundwater association
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Made in USA

Rock-Tech International Company History

In 2008, a dream was conceived by two long-time business associates/friends of leaving the big corporate world in the DTH Drilling Industry and reach for the stars…

On April 1, 2008 (and we were not kidding!), that dream was put in motion and came to fruition with Rock-Tech International being formed by Judy Herndon and David Griffin. Rock-Tech International is headquartered in Alvarado, Texas. Judy has over 29 years industry experience in the water well, oil and gas drilling industry and David has over 34 years industry experience including 12 years living in the Middle East working in Oil/Gas drilling operations.

From its start, the company has been involved in the manufacture and product offering of DTH drilling tools. Judy and David believe there is a tremendous opportunity to provide prospective customers with better personal service along with proven quality products from a small highly customer focused operation.

Rock-Tech International

"Rock Technology for the 21st Century and Beyond"


Judy B. Herndon - President

Judy Herndon has 29 years of experience in manufacturing and selling DTH products.  She was raised in the oil & gas industry with her father being one of the partners who started a drilling company in San Angelo, TX.  She spent many days & weekends out at the drill rigs while she was growing up, it was just a family thing. 

Judy started her career in DTH products in 1981 as an Administrative Assistant and quickly moved into sales.  She moved up to Sales Manager and eventually Vice President of the manufacturer.  After 15 years, Judy felt she needed to make a career move and she started another long and successful career with another manufacturer of DTH products.  Again after 12 years of service with this manufacturer, she decided that it was time to take a BIG jump to manufacturing and selling from her own business. 

In 2008, Judy and her business partner started ROCK-TECH INTERNATIONAL.  Judy has taken her hands on experience of many days out in the field, working with the distributors on the drilling rigs and created a successful partnership with the distributors of the DTH products.  Judy tries to put herself in her distributors' shoes and works with them to get them the best quality product as quickly as possible.  If she can’t answer a driller’s question, she seeks answers from the engineer in order to get the driller back up and drilling as soon as possible.

Judy is married to Steve Herndon who is a Sales Manager for a manufacturer of pressure tanks that are used in the water well industry.  Her daughter, Heather Johnson, joined ROCK-TECH INTERNATIONAL in 2010 as inside sales and is learning quickly the DTH industry. Her background formerly was in transportation safety.  Judy's son, a former Marine, was in Iraq during Iraq Freedom. Upon his return, he graduated from college and is now a licensed electrician.  Judy is also a grandmother of two beautiful granddaughters. If you want to get her going, just ask her about the girls!

When people ask Judy if she will ever retire from this business she answers. "NO WAY, I love it too much, I will be walking around with a walker, still trying to sell hammers & bits."

David R. Griffin - Vice President/CFO

David was born and raised in the small Texas town of Lancaster, south of Dallas.   In 1973, David graduated from the University of Texas at Arlington with a Bachelors of Arts in Government, and then graduated a second time in 1974 with a Bachelor of Business Administration, Operations Management.  Two weeks after graduation, David left for a 9 year career in Saudi Arabia working with a drilling contractor for Aramco, the Saudi national oil company.

Hired as a management trainee, he started at the bottom as an Assistant Drillers’ "worm" working on workover and drilling rigs. He worked his way up to Drilling Superintendent responsible for three 10,000 ft drilling rigs.  In 1983, he was hired by Smith Tool International as the Sales Manager for Saudi Arabia, Syria, and Pakistan responsible for all tri-cone bit sales.  In 1987 he and his wife decided it was time to move home to the USA to raise a family where there was some green grass and no sandstorms!

At this time David was introduced to the DTH percussion Hammer and Hammer Bit market and worked with two Hammer and bit manufacturers in the Sales Manager position from 1987 until 2008.  Then in 2008 after becoming disgruntled with the large corporate environment, David decided that it was time to do his own thing.   Thus on April 1, 2008 (with no kidding in mind), he and a close industry friend/business associate (with 63 years combined total experience in the drilling industry) formed their new company,  ROCK-TECH INTERNATIONAL.

David gives credit to his Mom and Dad (Gene and Estelle Griffin) for his success in life and business based on their examples of strong work ethics, moral ethics, and faith in God.

David and his wonderful soul mate Beth have been happily married for 25 years and have 3 sons, Michael (5 years in the USAF and now returning to University of Texas Arlington to complete his college degree and Masters),  Sean (working in customer service), and Scott ( attending Texas A&M at Corpus studying Marine Biology).