About PH Tool

PH Tool Reference Standards, headquartered in Pipersville, PA, has supplied the NDT industry with high quality Reference Standards and Test Blocks since its founding in 1973.

Whether you need EDM notches, Flat-bottom holes, Micro-holes, or Test Blocks, PH Tool can handle your order. We are a family-owned and managed business, started in 1973 by Phil Herman Sr., Founder/Chief Technology Officer. Phil Herman Jr. joined the business in 1991 and now serves as President/CEO. Phil Herman Jr. is a graduate of Drexel University (BS) in Philadelphia, PA and Villanova University (MBA) in Villanova, PA and joined the company after a decade in program management in the aerospace industry.

The entire staff of skilled toolmakers, machinists, technicians, customer service, and support personnel is dedicated to the development and manufacture of the finest quality reference standards available today. Our robust growth and excellent reputation in the Non-Destructive Testing (NDT) world can be attributed to our emphasis on quality, attention to detail and innovative approaches to meeting the reference standard needs of our valued customers.


Phil Herman Sr.
Founder/Chief Technology Officer


Phil Herman Jr.

Our Reference Standards and Test Blocks are used in ultrasonic, eddy current, magnetic particle and liquid penetrant testing. Reference Standards can be fabricated from customer supplied pipe, tube, bar, plate or other items. Twenty-four hour RUSH service is available on many standards. We will supply the material to your specifications if needed.

Standard Test Blocks are available in steel, stainless steel and aluminum. Many are available from stock for immediate delivery. Test Blocks in exotic alloys are also available, including: alloy steel, stainless steel, inconel, titanium, tungsten, tantalum, copper-nickel, NAB, monel, metal matrix composites and others. Specials can be fabricated to your design by our fully-equipped CNC machine shop. All Test Blocks are permanently engraved with the block description, material and serial number.

Our QA Program meets all industry and government specifications. All Reference Standards and Test Blocks are delivered with an automated Certification Report providing NIST traceability. Replicas of EDM notches are archived at PH Tool and are available if needed.

Throughout our history, PH Tool has earned an excellent reputation with our customers for supplying the best Reference Standards and Test Blocks available. Our manufacturing and technical support are always prepared to assist the NDT engineer or technician with their Reference Standard needs. Meeting the demands of the increasingly complex and quality-conscious NDT marketplace is a challenge we gladly accept. We welcome your inquiries and look forward to serving you.