Once upon a time in a bustling laboratory in Nagoya, there was a test piece of vulcanized rubber named . Dumbbell No. 3 was a simple soul, molded into a precise shape with a narrow waist, born to serve the prestigious Japanese Industrial Standard (JIS) K 6251 .
For official certification and compliance, always obtain the latest version (2023) from an authorized distributor like the Japanese Standards Association. This investment ensures that you are working with the most current legal and technical guidelines, safeguarding the quality and reliability of your rubber products.
Dumbbell specimens are preferred for absolute tensile data, while ring specimens eliminate stress concentration at clamping points. Specimen Type Common Application Characteristics Universal standard testing
Dumbbell specimens are the most common because they confine the highest stress concentration to a specific, measurable gauge length. Dumbbell Specimen Classifications
Current active edition; reflects latest international alignment. April 20, 2017
Chemically cross-linked rubbers (e.g., traditional car tires, seals).
The testing apparatus must include:
This version (often searched as a PDF) is based on the international standard ISO 37:2011 , incorporating modifications tailored to the Japanese industry.
An extensometer (optical, laser, or clip-on) tracks the distance between the gauge marks on the dumbbell piece to measure elongation without slipping interference. The machine records the continuous force-displacement loop until physical failure occurs. International Equivalents