This hardness tester comprises the very best in “state of the art” design along with dynamic precision only found at Phase II. The 900-331 Rockwell scale hardness tester is easy to operate, yet engineered to obtain highly sensitive and accurate readings. Conforming to ASTM E-18 Rockwell Hardness standards, the 900-331 tester will offer unmatched repeatability in all standard Rockwell Hardness scales (table shown below). A perfect, rugged performer suited for any environment including heat treat facilities, tool rooms, workshops, laboratories and inspection labs. Lifetime technical support is included on all Phase II Hardness Testers. So test away with confidence and a level of accuracy you will only find at Phase II.

Perfect for laboratories, workshops, tool rooms, inspection labs, etc.

Minor Load 10Kgf
Major Load 60Kgf, 100Kgf, 150Kgf
Test Force Application Dead Weight
Test Force Control Hydraulic Dashpot System
Results Display Analog Dial Gage
Vertical Capacity 6.7 in.
Throat Depth 6.6 in.
Height 30.0 in.
Width 8.50 in.
Depth 20.0 in.
Shipping Weight 242 lbs.


  • C-scale Diamond Indentor
  • 1/16″ Ball Indentor
  • 3- HRC Test Blocks
  • 1- HRB Test Block
  • 1-HRA Test Block
  • Test Table 5.87″ (150mm)
  • Flat Anvil 2.5″ (63mm)
  • Std. Vee Anvil
  • Accessory Case
  • Dust Cover


  • NIST/ASTM certified hardness test blocks, penetrators and kits are available.
  • This model is available with ASTM E18-08B or current certification
Scale Symbol Indenter Type
Ball dimensions indicate diameter
Preliminary Force
N (kgf)
Total Force
N (kgf)
Typical Application
A Spheroconical Diamond 98.07 (10) 588.4 (60) Cemented carbides, thin steel and shallow case hardened steel
B Ball 1/16″ (1.588mm) 98.07 (10) 980.7 (100) Copper alloys, soft steels, alum. Alloys, malleable iron, etc.
C Spheroconical Diamond 98.07 (10) 1471 (150) Steel, hard cast irons,pearltic malleable iron, titanium, deep case hardened steel & other material harder than HRB 100
D Spheroconical Diamond 98.07 (10) 980.7 (100 Thin steel and medium case hardened steel and pearlitic malleable iron
E Ball – 1/8″ (3.175mm) 98.07 (10) 980.7 (100 Cast iron, aluminum&magnesium alloys and bearing metals
F Ball – 1/16″ (1.588mm) 98.07 (10) 588.4 (60) Annealed copper alloys, and thin soft sheet metals
G Ball – 1/16″ (1.588mm) 98.07 (10) 1471 (150) Malleable irons, copper-nckel-zinc and cupronickel alloys
H Ball – 1/8″ (3.175mm) 98.07 (10) 588.4 (60) Aluminum, zinc and lead
K Ball – 1/8″ (3.175mm) 98.07 (10) 1471 (150) Bearing metals and other very soft or thin materials. Use smallest ball and heaviest load that does not give anvil effect
L Ball – 1/4″ (6.350mm) 98.07 (10) 588.4 (60)
M Ball – 1/4″ (6.350mm) 98.07 (10) 980.7 (100)
P Ball – 1/4″ (6.350mm) 98.07 (10) 1471 (150)
R Ball – 1/2″ (12.70mm) 98.07 (10) 588.4 (60)
S Ball – 1/2″ (12.70mm) 98.07 (10) 980.7 (100)
V Ball – 1/2″ (12.70mm) 98.07 (10) 1471 (150)
Additional DescriptionMore Details

Direct analog dial reading
Advanced design, easy to operate
Engineered to obtain highly sensitive and accurate readings
Conforms to ASTM E-18
Perfect for laboratories, workshops, tool rooms, inspection labs, etc.

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Ultrasonic Portable Hardness Tester MET-U1A & MET-U1A50

The PHASE II ultrasonic portable hardness testers are capable of measuring the surface hardness of a broad variety of metals on flat, round, thin or large surfaces. Unlike the standard Dynamic hardness testers, these “state-of-the-art” portable hardness testers incorporate “Ultrasonic UCI” technology, which enables the hardness testing of very thin and small workpieces, which otherwise could not be tested accurately using a portable device. Non-destructive in it’s function, these hardness testers allow for the testing of highly sensitive or finished parts that previously could not be tested in an operational setting. The non-destructive (ndt) feature of these hardness testersallow the operator to accurately test parts without causing physical or structural damage that would normally lead to disposal or refinish of operators part. That translates into less scrap parts/ lower mfg costs due to necessary inspections.

PHASE II offers two models of ultrasonic hardness testers that are capable of measuring the surface hardness of a broad variety of metals on flat, round, thin or large surfaces. Accurate measurements of steel, cast steel, alloy steel, aluminum, brass, bronze and copper are easily attained with this compact instrument.

The MET-U1A/U1A50 meets ASTM A1038-10 specifications.

UCI Portable Hardness Testing Method:
Model No’s. MET-U1A and MET-U1A50

Ultrasonic Contact Impedance is a hardness testing method based on the measurement of the frequency shift of a resonating rod caused by the essentially elastic nature of the finite area of contact between the indenter and the test piece during the penetration. Described as a hardness testing practice using a calibrated instrument by pressing a resonating rod with a Vickers style Diamond indentor with a fixed force against the surface of the part to be tested.

Pre-Programmed Scales/Material: Others combinations can be added upon request
Scales Material Measurement Range
Rockwell C Steel 20-67 HRC
Rockwell B Aluminum 59-99 HRB
Brinell Steel 75-650 HB
Vickers Steel 75-1000 HV
MET-U1A & MET-U1A50  Hardness Tester

Technical data for MET U1A/U1A50

UCI Probe
Length 160mm
Diameter 25mm
Indentation Depth 30µm
Pressure Force(MET-U1A) 1.5kgf
Pressure Force(MET-U1A50) 5kgf
Transducer Test Life (approx) 200,000
Min. Thickness for test 1mm
Min. Radius for Test 5mm
Max Roughness of surface (MET-U1A) Ra 2.5µm
Max Roughness of surface (MET-U1A50) Ra 4.5µm
Max Archive 100 Tests
Time of Test 1.5 seconds
Additional DescriptionMore Details

Standard Accessories:

Base Instrument
15N (1.5kgf) Hand-Held Probe (MET-U1A)
50N (5kgf) Hand-Held Probe (MET-U1A50)
Calibrated Test Blocks (2pc)
Custom Carry Case
Battery Charger
Operation Manual


Easy To Read Menu Operation
Large LCD Display w/ Back Light
USB Interface
Automatic Reading to All scales including Brinell, Rockwell, Superficial Rockwell & Vickers
Automatic Mean Value
Data Archive Capacity


Tolerance +/- 3.0% deviation of average from the reference value of the test block with a minimum of 5 tests
Minimum Thickness of sample(MET-U1A) .040” (1mm)
Materials: steel & cast steel, alloy tool steel, stainless steel, aluminum, brass, bronze, wrought copper alloy.
Battery type: 4-AA NiMH Re-Chargeable
Operating temperature: 5-104 degrees F
Dimensions: 180 x 80 x 43mm (HxWxD)
Weight: 720g (1.10lbs) w/probe


NIST/ASTM certified hardness test blocks are available.

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Tru-Blue II Hardness Tester

Since 1984, United has manufactured computer-controlled closed loop Hardness testers. Our second generation Hardness tester, the Tru-Blue II is the lowest priced US manufactured closed loop tester that meets ASTM E18, ISO 6508 specifications and NIST recommendations.

The Tru-Blue II comes standard with a Direct certification of the hardware calibration with NIST traceability and a factory one-year indirect calibration for customer specified hardness testing scales. The tester can be put into operation without the need for an additional on-site calibration or manufacturers assistance!

Having no dead weights, pivot points and knife edges to move out of adjustment, the Tru-Blue II can be moved to a new location without having to be re-calibrated. When mounted on United’s optional mobile stand, the Tru-Blue II is transportable to different locations.

Tru-Blue II Brochure

Tru-Blue Universal Features

rockwell tester

    • Same as Tru-Blue II
    • Test Forces in Kg.:2, 2.5, 4, 5, 6.25, 7.8125, 10, 15.625, 20, 30, 31.25, 40, 62.5, 100, 120, 125, 150, 187.5 and 250.
    • Test Dwell Settings selectable in 1 sec. increments: 5-30
    • Direct reading of one Brinell range.
    • Test Forces in Kg: 3, 5, 10, 30, 50, 100, and 120.
    • Test Dwell Settings selectable in 1 sec. increments: 5-30
    • Direct reading of one Vickers range.

MetTech offers a full line of hardness accessories

    • Hardness TesterRockwell, Brinell and Micro hardness test blocks: All test blocks come with a certification sheet containing all the necessary calibration information.
    • Rockwell diamond indenters: Scales A, C and N. All diamond indenters come with certifications.
    • Heavy load Vickers and Micro hardness diamond indenters: ¼ , 7mm and 8mm shank sizes and Tukon.
    • Carbide ball indenters: 1/16, 1/8, ¼ and ½ inch. 2.5, 5 and 10mm.
    • Anvils and support devices: Spots, flats, “V”, Vari and Jack rests.
    • Additional accessories: 2 inch roll mini serial and parallel printers, stationary and mobile stands, foot switch to activate test cycle, mini PS/2 keyboard.
Additional DescriptionMore Details

• 15 regular scales.
• 15 superficial scales.
• 5 preset load dwell times including plastics.
• Computer controlled application of loads.(closed-loop)
• Force measured via load cell
• Display resolution: points, tenths and hundredths.
• Serial, A Parallel for Dot Matrix printing & PS/2 Connections.
• Statistics Scale: Avg, range, min/max, Std deviation and number of tests.
• Vacuum fluorescent display.
• Automatic cylindrical correction.
• Scale to scale conversion.
• Parts IN/OUT limit alert.
• Bi-directional loading capability.
• Parts clamping device.
• Factory direct certification: Depth, load, hysteresis & timing.
• Factory indirect certification: B, C, 30N & 30T. Additional scales available.
• CE approved.
• 2-year warranty.
• Vertical capacities: 10, 14, 18 & 20 inches.Custom vertical heights available.
• Throat depth: 5.5 in 120-240 VAC, 50/60 Hz. Single phase, 1 amp.

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