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PHtool vs. NDT-KITS: Comparison of Calibration Block

In this blog post, you’ll read:PHtool and NDT-KITS are both vast brands that have produced varying calibration blocks, including customized blocks. How do you choose from these two brands? This article analysize each manufacturer’s advantages and their popular calibration blocks.

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Are you torn between these two brands of calibration block manufacturers?

PHtool and NDT-KITS are both vast brands that have produced varying calibration blocks, including customized blocks at the customer’s request. So, what distinguishes one from the other?

This article aims to help you decipher the best-suited brand for your calibration needs. We dissect each brand using a set of essential parameters that give you the most value in your quality inspection activities.

Without wasting any more of your time, let’s dive in. 


I. PHtool Calibration Block


1. About PHtool

PH Tool Reference Standards is a non-destructive tools company that manufactures high-quality test blocks and reference standards. With almost half a century of experience in producing non-destructive testing tools, PH Tools is quite popular.

Its steady but phenomenal growth is accredited to its emphasis on quality, detail, and unconventional methods of satisfying customers’ wishes. PHTool is also equipped with a robust technical staff of toolmakers and machinists devoted to designing and producing the best reference standards and calibration blocks.

Established in 1973, with its headquarters in Pipersville, PA, where it has continued to manufacture some of the best calibration blocks for the non-destructive testing community.


2. PHtool Popular Calibration Block


  • IIW-Type Blocks


IIW-Type Blocks


The IIW Type Blocks are basically of two types, IIW-Type I and IIW-Type II. The IIW-Type II Blocks are a slight modification of the IIW-Type I.



  • It is typically used for checking resolution and sensitivity. 
  • IIW-Type Blocks are also used for calibration of longitudinal transducers



  • 4.0 radius, 2.0 and 0.060 diameter hole, 0.240 deep x 0.080 wide slot, and 1.0 radiused slot x 0.060 deep x 0.120 wide.
  • IIW-Type Blocks’ dimensions – 1.0 x 4.0 x 12.0 (inch)



  • Step Blocks


Step Blocks


The Step Blocks are in varying types of Blocks, ranging from Magna Thin Step Blocks to 10 Step Blocks or even custom step blocks, depending on a customer’s request. It’s also available in ultra-thin blocks, tipsy step blocks, curved step blocks, etc.



  • It is used to measure linearity and thickness calibration



  • Dimensions are in variations of the type of selected step block
  • Designed and produced in a fitted wooden case which can be optional



  • ASME Calibration Blocks


ASME Calibration Blocks


ASME Calibration Blocks are of three different types, and they include ASME Sec V Basic Calibration Block, ASME Sec V Full Matrix Capture Calibration Blocks, and ASME Sec V Pipe Calibration Blocks, etc., depending on the purpose for which the calibration blocks are to be employed.



  • These calibration blocks are utilized to ascertain ultrasonic testing inspection of welds’ central reference response.



  • ASME Basic Calibration Blocks’ dimensions – ½ thick x 6¼ wide x 4.5 long



  • DSC Calibration Block 

DSC Block

The DSC Calibration Block or the AWS-Type Block can be made in Alloy, Steel, or Aluminum. 



  • The DSC AWS-Type Block can be used for setting the sensitivity and calibrating the distance of angle and typical beam inspection.
  • It also determines the refracted angle of angle-beam transducers and determines a beam’s exit point.



  • 3.0 radius includes a 0.375 deep x 0.032 wide radiused slot
  • 1.0 radius opposite a 3.0 radius.



  • V2 Block

V2 Block


The V2 (A4) Test Blocks are in steel, alloy, or aluminum blocks and are used in an on-site checking of the time base, beam angle and gain, and miniature shear wave probe index. It is designed and built-in in compliance with the British Standard.



  • Measuring time base, and angle of beam and gain
  • To measure shear wave probe index



  • Overall V2 (A4) Dimensions – (width) x 75mm long x 43mm tall
  • The width can either be 12.5, 20, or 25mm (you can choose the one that fits your inspection objectives)



  • SC Block

SC Block


As designed according to the AWS requirements, the SC Block has markings for angles 45, 60, and 70 engraved for precise measurement of refracted angle beams. It also can be employed to examine shear wave sensitivity calibration.



  • SC AWS-type block is utilized for shear wave sensitivity calibration.
  • Accurate refracted angle beams measurement



  • Double 0.062 diameter via holes, in compliance with BRR/AWS and ASTN E164 requirements
  • SC AWS-Type Blocks dimensions – 3.000 x 1.250 x 0.905



III. NDT-KITS Calibration Block


1. About NDT-KITS 

NDT-KITS, as a brand, is China’s topmost manufacturer and supplier of all things ultrasonic testing equipment. It is your reliable brand for quality calibration blocks at the best price possible.

NDT-KITS supplies numerous models of calibration blocks, reference blocks, and custom-made blocks as requested by the customer. NDT-KITS is equipped with sophisticated tools for high-level manufacturing of different types of standard calibration blocks.

Its calibration blocks are vastly deployed in various automotive, power generation, aerospace, petrochemical industries, etc. As it Is a subject of comparison in this piece, we’ll be examining the different calibration blocks supplied by NDT-KITS compared to its rivals.


2. NDT-KITS Popular Calibration Block


  • V-1 Calibration Block


V-1 Calibration Block


The V-1 Calibration Block is designed in compliance with the British Standard BS2704. It is utilized to calibrate ultrasonic flaw detection tools with engraved mark scales for easy monitoring of calibrated signals at intervals.



  • Can be used on-site and in labs for calibrating flaw detection equipment



  • V-1 Calibration Block dimension – 300mm x 100mm x 25mm
  • Gross weight – approximately 6.5kg
  • Net weight – 5kg
  • Engraved reference mark scales
  • 12 months warranty



  • V-2 Calibration Block


V-2 Calibration Block


The V-2 Calibration Block includes engraved markings of 35-70 degrees, and it’s a small calibration block employed in the on-site checking of beam angle and gain, minute shear wave index, and time base.



  • On-site measuring small-scale shear wave probe, time base, and beam angle and gain.



  • Weight – 0.75kg
  • Dimensions 8 x 5 x 13
  • Engraved reference mark of 35 to 70 degrees.
  • 25mm to 50mm radius, 1.5mm or 5mm hole



  • DC Calibration Block


DC Calibration Block


The DC Calibration Block is fabricated with a 25.4mm radius overlayed by a 50.88mm radius on an 1800 segment. And it is typically deployed for shear wave distance calibration, designed in compliance with ASTM E164 and BRR/AWS X-1 recommendations.



  • Measurement of shear wave distance calibration 



  • DC Calibration Block Dimensions – 25.4mm and 50.8mm radii
  • Weight – 1.5kg
  • Regulatory standards – ASTM E164 and BRR/AWS X-1 recommendations
  • Warranty – 12 months



  • SC Calibration Block


SC Calibration Block


The SC Calibration Blocks include a 1.6mm holes diameter through holes or a .062”. This is an AWS-Type calibration block employed to measure shear wave sensitivity calibration.



  • Measurement of shear wave calibration



  • Warranty – 12 months
  • SC Calibration Block Dimension – 7.7 x 3.2 x 2.3 cm
  • Delivery time – 1 to 2 weeks
  • Specifications standards – ASTM E164, BRR/AWS



  • Step Block

Step Blocks are in different variations of 4-step, 5-step, or 10-step variations, with the thickness of each variation being modified as the number of calibration steps increases. This is deployed to ascertain linearity and thickness calibration in compliance with ASTM E797.



  • To confirm accurate and precise thickness and linearity calibration



  • 4-Step Block dimension – 80mmx20mmx25mm, weighs 0.6kg
  • 5-Step Block dimension – 100mmx20mmx12.5mm, weighs 0.63kg
  • 10-Step Block dimension – 200mmx20mmx20mm, weighs 1.1kg
  • Warranty – 12 months



IV. PHtool vs. NDT-KITS: Which is the Best for you?


To decide the best of these two brands it is essential to consider them under the following criteria. 


  • Instrument Application: Calibration Blocks manufactured by both NDT-KITS and PHtool are undoubtedly one of the best in the industry. However, NDT-KITS offers more OEM services, giving them a wider range of applications. OEM services also assist other manufacturers that utilize other components for faster completion of their products.
  • Measurement Accuracy: PHtool’s calibration blocks also measure precise readings and measurement, but when NDT-KITS calibration blocks are deployed, it doesn’t just assist you in measuring more accurately. There are engraved mark scales for easy monitoring of calibrated signals at intervals.
  • Price: PHtool manufactures calibrated blocks with other components that may add cost and increase the price after production, but with NDT-KITS’ strategic positioning, they can manufacture high-quality calibration blocks at very competitive prices that are budget-friendly.
  • Delivery Date: Most calibration blocks manufactured by PHtool are likely to take more time to produce, but NDT-KITS produces bespoke products fitted to customer requirements and delivers to customers anywhere in the world at the shortest possible production and delivery time.
  • Warranty: PHtool’s calibration blocks do not come with a warranty. On the other hand, NDT-KITS gives a minimum of 12 months warranty on every of their calibration blocks. 



V. Your Perfect Pick: NDT-KITS


NDT-KITS was a pioneering manufacturer of ultrasonic flaw detection equipment in China more than three decades ago and has since taken a continuous progressive leap to be the best that they are now.

They focus on research and development, investing more than ten percent of their sales in research and development. Also, NDT-KITS supplies more than a hundred models of calibration blocks and reference blocks worldwide. They have also supplied calibration blocks to SGS for over a decade and continue to provide OEM services and rapid delivery.

NDT-KITS has a high-level manufacturing process with sophisticated manufacturing tools such as the high-accuracy optical jig borer and a horizontal grinding machine. It also manufactures the best calibration blocks using the Electric Discharge Machining (EDM) technology.


➤ Related Article: How to Import Calibration Blocks from China?




What does all this mean? PHtool has some of the best calibration blocks manufactured by its top machinist and engineers, who are devoted to making the best machines for its growing customer base. However, this is not enough.

NDT-KITS has extensive industry experience and a large pool of expertise to manufacture some of the best calibration blocks, their advanced production tools, and their vast experience in the ultrasonic testing equipment industry. NDT-KITS also delivers in the shortest time possible and offers very affordable and competitive prices.

Now you know who your trusted supplier is for any form of Calibration Blocks with this write-up.

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