Hardness Testing Consumables

Introduction

Hardness testing is a fundamental characterization technique in metallography that measures a material's resistance to permanent deformation. Hardness values provide critical data that correlates with material properties such as tensile strength, wear resistance, ductility, and machinability. These measurements are essential for quality control, heat treatment verification, material selection, and failure analysis in metallographic laboratories.

Proper hardness testing requires calibrated equipment, certified test blocks, and appropriate consumables matched to your testing method. Surface preparation is crucial; specimens must be polished to remove work-hardened layers and ensure flat, perpendicular mounting for accurate indentation measurements.

The table below presents a relative hardness comparison between common testing methods for steel. While these conversions offer general guidance based on ASTM E140 standards, actual values may vary significantly depending on the specific material tested, its composition, and microstructure. Always perform tests using the specified method when critical data is required.

Rockwell Hardness

The Rockwell hardness test is an indentation hardness test that measures the permanent depth of penetration produced by a force/load applied to an indenter. The test begins with the application of a minor load (preload) of 10 kgf, which seats the indenter and establishes a reference position. A major load is then applied (60, 100, or 150 kgf depending on the scale), creating a deeper indentation. When the major load is removed while maintaining the minor load, the depth difference determines the Rockwell hardness value.

Rockwell testing is fast, requires minimal surface preparation, and provides direct hardness readings without optical measurement. Different Rockwell scales use specific indenter types and loads: diamond cone indenters (Brale) for hard materials (HRA, HRC, HRD scales) and tungsten carbide ball indenters for softer materials (HRB, HRF, HRG scales). Superficial Rockwell scales (15, 30, or 45 kgf major loads) are used for thin materials, case-hardened layers, and small parts.

Typical Applications:

• Quality control of heat-treated steel components (gears, shafts, dies, tools)
• Monitoring heat treatment consistency and case depth verification
• Evaluating weld heat-affected zones (HAZ) in structural assemblies
• Rapid production-line inspection with minimal sample preparation
• Through-hardening verification on forgings and castings

Brinell Hardness

The Brinell hardness test measures the diameter of an indentation produced by a hardened steel or tungsten carbide ball pressed into the test surface under a known load. Standard testing uses a 10 mm diameter ball with loads ranging from 500 to 3000 kgf, though smaller diameter balls (2.5, 5 mm) can be used for thin or small specimens. The load is typically applied for 10-15 seconds for ferrous metals and up to 30 seconds for softer non-ferrous metals to allow for creep.

The Brinell Hardness Number (HBW for tungsten carbide ball, HBS for steel ball) is calculated by dividing the applied load by the spherical surface area of the indentation. Tungsten carbide balls are required for materials harder than approximately 450 HBW to prevent ball deformation. The large indentation size makes Brinell testing ideal for coarse-grained materials, castings, and forgings where microstructural inhomogeneity might affect smaller indentation tests.

Typical Applications:

• Testing large castings, forgings, and unmachined components with coarse grain structures
• Evaluating cast iron, aluminum alloys, copper alloys, and soft steels
• Correlating hardness with tensile strength using empirical relationships
• Field testing where portable Brinell testers can be used on-site
• Materials too soft or too coarse-grained for Rockwell testing

Vickers Hardness

The Vickers hardness test uses a square-based diamond pyramid indenter with a face angle of 136° to create an indentation in the test surface. The Vickers Hardness Number (HV) is calculated by dividing the applied load by the surface area of the indentation, which is derived from optical measurement of the two diagonals. The major advantage of Vickers testing is that the hardness value is largely independent of the applied load, making it suitable for testing across an extremely wide hardness range.

MacroVickers testing uses loads from 1 kgf to 120 kgf and is appropriate for bulk hardness measurements on materials from soft metals to hardened tool steels and ceramics. The test requires a polished, flat surface and optical measurement equipment to accurately measure indentation diagonals. Vickers testing is particularly useful when a single hardness scale is needed across multiple material types or when testing gradients such as carburized case depths.

Typical Applications:

• Hardness testing across extremely wide ranges (from soft metals to carbides)
• Case depth measurement and carburizing/nitriding verification
• Research and development requiring consistent hardness scale
• Thin materials and small components requiring precise indentations
• Hardness gradient analysis across weld zones and heat-affected areas

Microhardness

Microhardness testing measures hardness on a microscopic scale using very light loads, typically ranging from 10 gf to 2000 gf (lower loads from 1-10 gf are sometimes used for ultra-thin films). This technique enables hardness measurement of individual microstructural phases, thin surface layers, small parts, and localized regions that cannot be tested with macro-scale methods. Microhardness testing requires metallographically polished samples and precise optical measurement of very small indentations under a microscope.

Vickers microhardness (HV) uses the same 136° diamond pyramid indenter as macro Vickers testing but with much lighter loads. The indentation appears as a square when viewed from above, and both diagonals are measured to calculate hardness. Vickers microhardness is preferred for measuring individual phases in alloys, through-depth hardness profiles, and general-purpose microhardness testing where the indentation symmetry provides consistent results.

Knoop hardness (HK) uses an elongated pyramidal diamond indenter with a rhombic base that produces an indentation with a length-to-width ratio of approximately 7:1. Only the long diagonal is measured for hardness calculation. The elongated, shallow indentation makes Knoop ideal for very thin coatings, brittle materials prone to cracking, and anisotropic materials where directional hardness differences are being investigated. Knoop indentations recover less elastically than Vickers, providing more accurate readings on materials with high elastic recovery.

Typical Applications:

• Characterizing individual phases in multi-phase alloys and microstructures
• Measuring hardness of thin coatings, platings, and surface treatments (CVD, PVD, nitriding)
• Case depth profiling with sequential indentations from surface to core
• Brittle materials including ceramics, glasses, and intermetallic compounds
• Small components such as wires, foils, and micromechanical parts
• Failure analysis requiring localized hardness measurements near cracks or defects

Rockwell Regular Test Blocks

Hardness Scale	Part No.	Penetrator	Load	Ranges	Material
A Scale	RA10	C Diamond	60 Kg	A60-A84	Steel
A Scale	RA20	C Diamond	60 Kg	A20-A59	Brass
A Scale	RA30	A Diamond (Carbide)	60 Kg	A88 & up	Carbide
B Scale	RB10	1/16" Ball	100 Kg	B10-B92	Steel
B Scale	RB20	1/16" Ball	100 Kg	B90-B130	Steel
C Scale	RC10	C Diamond	150 Kg	All	Steel
D Scale	RD10	C Diamond	100 Kg	All	Steel
E Scale	RE10	1/8" Ball	100 Kg	All	Brass
F Scale	RF10	1/16" Ball	60 Kg	All	Brass
G Scale	RG10	1/16" Ball	150 Kg	G2.5-G64	Brass
G Scale	RG20	1/16" Ball	150 Kg	G66 & up	Steel
H Scale	RH10	1/8" Ball	60 Kg	All	Brass
K Scale	RK10	1/8" Ball	150 Kg	All	Brass
L Scale	RL10	1/4" Ball	60 Kg	All	Brass
M Scale	RM10	1/4" Ball	100 Kg	All	Brass
P Scale	RP10	1/4" Ball	150 Kg	All	Brass
R Scale	RR10	1/2" Ball	60 Kg	All	Brass
S Scale	RS10	1/2" Ball	100 Kg	All	Brass
V Scale	RV10	1/2" Ball	150 Kg	All	Brass

Note: Aluminum test blocks are available in "B", "E", "F", "G", "H", and "K" scales, although the range is more limited.

Rockwell Superficial Test Blocks

Hardness Scale	Part No.	Penetrator	Load	Ranges	Material
15N Scale	S15N10	N Diamond	15 Kg	All	Steel
30N Scale	S30N10	N Diamond	30 Kg	All	Steel
45N Scale	S45N10	N Diamond	45 Kg	All	Steel
15T Scale	S15T10	1/16-inch Ball	15 Kg	All	Brass
30T Scale	S30T10	1/16-inch Ball	30 Kg	All	Brass
45T Scale	S45T10	1/16-inch Ball	45 Kg	All	Brass
15W Scale	S15W10	1/8-inch Ball	15 Kg	All	Brass
30W Scale	S30W10	1/8-inch Ball	30 Kg	All	Brass
45W Scale	S45W10	1/8-inch Ball	45 Kg	All	Brass
15X Scale	S15X10	1/4-inch Ball	15 Kg	All	Brass
30X Scale	S30X10	1/4-inch Ball	30 Kg	All	Brass
45X Scale	S45X10	1/4-inch Ball	45 Kg	All	Brass
15Y Scale	S15Y10	1/2-inch Ball	15 Kg	All	Brass
30Y Scale	S30Y10	1/2-inch Ball	30 Kg	All	Brass
45Y Scale	S45Y10	1/2-inch Ball	45 Kg	All	Brass

Note: Aluminum test blocks are also available upon request.

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Rockwell Testing Accessories

Rockwell hardness testing requires precision accessories to ensure accurate and repeatable test results. Our comprehensive selection includes diamond penetrators, ball penetrators, anvils, and maintenance accessories for all major Rockwell hardness testing equipment.

Diamond Penetrators

Each diamond penetrator is mounted in conformity with its grain structure to assure balanced pressure and prevent early wear or breakage. They are precision ground, lapped, and polished. We also subject each diamond penetrator to a strict performance test before it is approved for sale.

Part No.	Description
P1010	Standard "C" Diamond Penetrator
P1020	Standard "N" Diamond Penetrator
P1030	Carbide "A" Diamond Penetrator
P1040	'Versitron'® - type "C" Diamond
P1045	'Versitron'® - type "N" Diamond
P1050	'Indentron'® - type "C" Diamond
P1060	'Indentron'® - type "N" Diamond
P1070	"C" & "N" Combo Slip-in Diamond Penetrator
P1080	"C" Portable Diamond Penetrator
P1090	'Veritron' - type Tapered Diamond

Note: Versitron® and Indentron® are registered trademarks for Newage Testing Instruments, Inc.

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Ball Penetrators

Ball penetrators are used for softer materials in Rockwell hardness testing. They are available in various sizes to accommodate different material types and testing requirements.

Part No.	Description
P2010	1/16-inch Ball Penetrator Unit
P2015	1/16-inch Balls (50 each)
P2020	1/8-inch Ball Penetrator Unit
P2025	1/8-inch Balls (25 each)
P2030	1/4-inch Ball Penetrator Unit
P2035	1/4-inch Balls
P2040	1/2-inch Ball Penetrator Unit
P2045	1/2-inch Balls
P2055	1/16-inch Carbide Balls

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Anvils

Anvils provide the support surface for specimens during Rockwell hardness testing. Different anvil types are designed to accommodate various specimen shapes and sizes, ensuring proper support and accurate test results.

Part No.	Description
A1010	Pedestal Spot (1/4-inch) Anvil
A1020	1-1/2-inch Flat Anvil
A1030	2-1/2-inch Flat Anvil
A1040	Shallow "V" Anvil
A1050	Standard "V" Anvil
A1060	4-inch "V" Anvil
A1070	Gooseneck Anvil
A1080	Diamond Spot Anvil

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Other Rockwell Accessories

Additional accessories and consumables for maintaining and optimizing Rockwell hardness testing equipment performance.

Part No.	Description
A2010	Index Adjusting Unit
A2020	Cross Pin Unit (For Dials)
A2030	Elevating Unit Oil (1/2 pint)
A2040	Dash Pot Oil (1/2 pint)
A3010	Gooseneck Adapter 2-1/2-inch
A3020	8-inch Testing Table
A3030	Jack Rest (8-inch or 12-inch)
A3040	Extension Support
A3050	Bulbs

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Brinell Test Blocks and Accessories

All Brinell Test Blocks come certified to applicable standards. We adhere to a strict procedure for our calibration process, and the accuracy of our tester is maintained using a proving ring and load cell both traceable to N.I.S.T. The readings are done using a stage micrometer, which is also calibrated and traceable to N.I.S.T.

Part No.	Description	Range
B3000	3000 Kg Load 10mm Ball	All Hardness Ranges
B2000	2000 Kg Load 10mm Ball	All Hardness Ranges
B1500	1500 Kg Load 10mm Ball	All Hardness Ranges
B1000	1000 Kg Load 10mm Ball	All Hardness Ranges
B0500	500 Kg Load 10mm Ball	All Hardness Ranges
B0250	250 Kg Load 10mm Ball	All Hardness Ranges
B0187	187.5 Kg Load 10mm Ball	All Hardness Ranges
BT010	Telebrinell Test Blocks	All Hardness Ranges

Brinell Accessories

Part No.	Description
P3010	10mm Steel Balls
P3020	10mm Carbide Balls

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Microhardness Test Blocks and Accessories

We manufacture our microhardness test blocks to exceed industry standards. All of our micro test blocks are mirror polished and mounted to provide the best possible test surface. Each mirror-polished heavy-load Vickers test block has the same surface area provided by our Rockwell test blocks, so you get the most test opportunities for your money.

Part No.	Description	Range
MV010	Vickers (1 gram to 1000 grams)	All Ranges
MV020	Heavy Load Vickers (1 Kg to 50 Kg)	All Ranges
MK010	Knoop (1 gram to 1000 grams)	All Ranges

Note: When ordering, please specify Knoop or Vickers, load, and the hardness range you require.

Microhardness Penetrators

Part No.	Description
P1110	Vickers Diamond Penetrator
P1120	Knoop Diamond Penetrator

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Hardness Testing Tips

• Choose the Right Indenter: Match the indenter type to your testing method (Vickers, Brinell, Rockwell).
• Calibration: Use certified calibration blocks regularly to ensure accurate results.
• Surface Preparation: Ensure samples are polished and clean for accurate readings.
• Maintenance: Inspect and clean testing components regularly to extend equipment life.

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Related Equipment

Rockwell Hardness Testers

Precision-engineered Rockwell hardness testers supporting standard and superficial scales (HRA, HRB, HRC) with configurable test forces from 15 Kgf to 150 Kgf. Available in manual, semi-automated, and fully automated configurations for diverse testing workflows.

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Brinell & MacroVickers Testers

Versatile hardness testing systems supporting test forces from 1 kgf to 3000 kgf for Brinell and MacroVickers methods. Features precision optics with multiple magnification options for accurate indent measurement and detailed sample observation.

Explore Brinell/Vickers Testers

Microhardness Testers

Precision microhardness testing for thin films, coatings, and individual microstructural phases. Support for Vickers and Knoop methods with test forces from 10 gf to 2000 gf, featuring advanced automation and digital measurement systems.

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Frequently Asked Questions

Common questions about hardness testing

What's the difference between Rockwell, Brinell, and Vickers hardness testing methods?

Rockwell testing uses a diamond cone or steel ball indenter with specific loads, providing quick results with minimal surface preparation. Brinell uses a larger ball indenter with heavier loads, ideal for materials with coarse or non-uniform grain structures. Vickers uses a pyramid-shaped diamond indenter and is versatile across all hardness ranges, from soft to extremely hard materials. Each method has specific applications based on material type, sample size, and required accuracy.

How often should I calibrate my hardness testing equipment?

Per ASTM standards (E18, E10, E384), hardness testers should be verified daily using certified test blocks before beginning testing. Formal indirect calibration should be performed at least annually, or whenever the tester is moved, serviced, or shows suspect results. For critical applications or high-volume testing labs, more frequent verification intervals may be required. Always use certified test blocks that are traceable to national or international standards (NIST, ISO, ASTM).

What surface preparation is required for accurate hardness testing?

The test surface must be flat, clean, and free from oxides, scale, or contaminants. For Brinell and Rockwell testing, grinding to 240-320 grit is typically sufficient. MacroVickers testing requires polishing to at least 600 grit for clear indent measurement. Microhardness testing (Vickers and Knoop) requires a full metallographic polish, typically through final polishing with alumina or colloidal silica to a mirror finish, since indentations are very small and any surface irregularity will distort measurements. The surface should be perpendicular to the indenter axis, and the sample must be securely mounted to prevent movement during testing.

Can I convert hardness values between different scales?

Yes, approximate conversions between hardness scales are available in standards like ASTM E140, but these conversions are not exact and should be used with caution. Conversion accuracy depends on the material being tested, as different materials respond differently to various testing methods. For critical applications, it's best to perform the actual test using the required method rather than relying on conversions. Always specify which hardness scale was used in your reports.

What's the difference between macro-hardness and microhardness testing?

Macro-hardness testing (Rockwell, Brinell, standard Vickers) uses larger loads (typically 1 kg to 3000 kg) and measures the bulk hardness of a material. Microhardness testing (Vickers or Knoop) uses very light loads (10 g to 1000 g) and is designed for testing small areas, thin coatings, individual microstructural phases, or case-hardened layers. Microhardness testing requires more extensive sample preparation and optical measurement of the indentation.

How do I choose the right test block hardness range for calibration?

Select test blocks that match the hardness range of the materials you typically test. For example, if you primarily test hardened steel (HRC 50-65), use test blocks in that range. It's recommended to have at least three test blocks covering low, medium, and high ranges for your application. Test blocks should be certified and within their calibration validity period. Replace test blocks when they show wear, damage, or when indentation density exceeds the maximum allowed per testing standards.