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NDT DLH-300 & DLH-330 Pen Type Hardness Testers

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NDT DLH-300 & DLH-330 Pen Type Hardness Testers
Product Description
Additional Info
Product Literature

NDT DLH-300 & DLH-330 Pen Type Hardness Testers



  • Pen type design, self-contained (Impact device display integrated): no cables.
  • Unique 1.77" large-screen OLED color display
  • Interchangeable D impact device (standard) / DL impact device (optional) can be used for a dual purpose unit; it can also be used in restricted area measurements.
  • Highly accurate in any impact direction 360° and automatically identifies impact direction and gravity compensation
  • Easy to operate - 4 soft keys above the screen achieve various functions.


DLH-300 DLH-330 
Display Type: 1.77" OLED Screen with resolution 160 x 128 pixels
Hardness Scale: HL, HB, HRB, HRC, HV, HS, Tensile Strength
Measuring Range: HLD (200-960), HRC (19.8-68.5), HB (30-651), HV (80-976), HS (26.4-99.5), HRB (13.5-100), Tensile Strength (375-2639)
Impact Device: D Type Impact device (standard); Optional DL type impact device D-Type Impact device (standard); Interchangeable DL Probe
Accuracy: ±6HLD (HLD=800); Repeatability < 6HLD(HLD=800)
Measuring Direction: 360° Automatic Position Correction 
Material: Steel & Cast Steel, Stainless Steel, Gray Cast Iron, Nodular Cast Iron, Cast Aluminum Alloy, Sintered Metal, Copper-tin Alloy, Brass, Forged Steel
Resolution: 1HL, 1HV, 1HB, 0.1HRB, 0.1HRC, 0.1HS 
Calibration:  Automatic 
Language:  English, Chinese, Spanish, Japanese 
Memory:  1,000 groups, each group includes 6 testing results and 1 average value 
Communication:  USB Port, used for recharging and data transmission 
Software:  Optional VIEW Software for transmission, storage and printing  LmView software measurement data management, archiving, printing and other operations
Power:  AAA Lithium Battery, Capacity of 600MA/H, 3.7V and low voltage warning 
Instrument Shut-Off:  Automatically will shut off after 3 minutes of inactivity 
Temperature: 14°F to 122°F (-10°C to 50°C)
Dimensions: 5.9" x 1.8" x 0.9" (150 x 46 x 23 mm) - D Type Probe 8" x 1.8" x 0.9" (204 x 46 x 23 mm) - DL Type Probe
Weight: 0.24 lbs. (110g) with D type impact device 0.27 lbs. (125g) with DL impact device
Standard: GB/T 17394-1998, ASTM A956

DLH-300 & DLH-330 Hardness Tester Kits Include:

  • Instrument
  • D Type Impact device
  • Test Block with HLD value
  • Small Supporting Ring
  • Charger
  • Cleaning Brush
  • Instruction Manual
  • Warranty Card
  • Certificate of Conformity
  • Instrument Case

DLH-330 Additional Accessories:

  • DL Impact device
  • LmView Software
  • USB Communication Cable

additional info tab with red arrow

Note: Below prices include current U.S. Duties & Import Costs*.

*subject to change

How Does It Work?

A spring in the probe projects the tungsten carbide ball tipped indenter at the test piece. Impact velocity is measured immediately prior to impact and then on rebound. The quotient is computed and displayed as the Leeb Hardness Value. On hard materials, the rebound velocity will be higher than that from softer materials, which will absorb more of the impact energy.

For a correct and repeatable measurement, certain conditions must be met:

  • The material must be smooth and free of paint, rust, oxide, etc...
  • The grain size of the test part must be small in relation to the indentation size.
  • The material cannot move or be deflected by the impact of the indenter.
  • Correction factor must be applied for the material's elastic modulus.
  • Correction for the effect of gravity must also be made.


Surface: The test piece surface needs preparation by filing, sanding or grinding. As a general rule, if you drag your thumbnail across the surface and it drags, the surface is too rough.

Grain Structure: Materials such as cast iron, that have a coarse (large) grain structure, will cause inconsistent measurements. The use of a much large identer "G" probe will often correct for this condition.

Thickness & Mass: Test parts that have a low mass or thickness need to be supported to prevent movement or deflection.

Material: Selection of the material corrects for material type. The following materials can be selected: Steel / Cast Steel, Gray Cast Iron, Nodular Cast Iron, Cast Aluminum, Brass, Bronze, Copper, Stainless Steel, Forged Steel and Tool Steel*

Probe Position: Set; Up, Down, Sideways, 45° up or 45° down

*Leeb measurements are affected by the material elasticity. To a large degree this is taken care of by selecting the most similar material type from the Material list. If you find that your measurements are a bit high or low, it is because the built-in correction factor does not match your material. You can try a different material to see if this gets you closer to a correct measurement. You can also use a known hardness sample of your test material (having enough mass and thickness) to determine the +/- error and then adjust the reading to match using the Calibration facility. 

Please Note: To add an item/multiple items to your shopping cart, check the corresponding box/boxes and click "Add To Cart"
Part #
Product Name Part # Price Qty
DLH-300 Pen Type Hardness Tester HT-SY-DLH300 $950.00
DLH-330 Pen Type Hardness Tester HT-SY-DLH330 $1,050.00
DL Probe for the DLH-330 Hardness Tester HT-SY-DLH330-Probe-DL $210.00