Hardness Testing
Hardness testing is a benchmark of materials evaluation, quality control, and research & development. Regardless of the application, determination of hardness is critical. Sturbridge Metallurgical offers a wide range of hardness testing techniques, each specifically tailored for the specific hardness scale, material type, and sample size being tested.
Microhardness - Vickers & Knoop:
Micro indentation hardness (loads 10 – 1000 grams) is the most commonly used hardness method for resolving hardness variation over small distances or to test parts too small to withstand larger forces of full scale testing.
Subtle hardness variations can be intentional or accidental. Microhardness profiles have precision and accuracy to determine hardness changes due to heat treatment, surface modification, phase/carbide segregation, and more. Similarly, determinations may also be made to characterize detrimental features such as decarburization, embrittlement, overheating and more.
In general the Vickers scale is best suited for determined bulk properties of the material. The Knoop scale, features an oblong diamond which is optimized for placing close to the sample surface or within thin, brittle coatings.
Equipment: Qty. 3 Phase II Micro Hardness Testers with Digital Image Analysis Software
Common Uses: Material hardness determinations of small parts, surface hardness, heat treat evaluations, hardness profiles and more. Nitriding, carburization/decarburization, surface treatment, carbide segregation, etc.
Specification: ASTM E384 Standard Test Method for Microindentation Hardness of Materials
Rockwell & Superficial Rockwell Hardness Testing:
Rockwell hardness is above all the most commonly referenced hardness scale across all industries. The accurate determination of Rockwell hardness is essential in product development, quality control, and material certification.
Rockwell hardness numbers offer valuable correlations to many material properties in a simple bench top test that is rapid and minimally destructive. Hardness numbers provide insight into properties such as tensile strength, ductility, wear resistance, and other physical characteristics.
Equipment: Phase II Rockwell Hardness Tester (A, B, & C Scales)
Common Uses: Bulk Material hardness determinations of finished parts or test coupons.
Specification: ASTM E18 Standard Test Method for Rockwell Hardness of Metallic Materials.
Equipment: Phase II Rockwell Superficial Hardness Tester (N & T Scales)
Common Uses: Bulk Material hardness determinations of thin sheet metal.
Specification: ASTM E18 Standard Test Method for Rockwell Hardness of Metallic Materials.
Durometer Hardness Testing:
Durometer hardness testing is used for measuring the hardness of rubbers, polymers and elastomers by indentation. The durometer hardness test is commonly referred to as the Shore Durometer.
While there is minimal correlation between durometer hardness and other physical properties, durometer hardness remains a bench mark for manufacturing, processing and product comparison.
Equipment: Phase II Shore A Durometer & Phase II Shore D Durometer
Common Uses: Determination of rubber and polymer hardness.
Specification: ASTM D2240 Standard Test Method for Rubber Property – Durometer Hardness.