Rubber Property – Adhesion to rigid substrates – Method B (90° adhesion tensile strength)

ASTM D429 covers procedures for testing the static adhesional strength of rubber to rigid materials, most commonly metals. Method A tests rubber assembled between two parallel metal plates in tension. Method B is a 90-degree stripping test from one metal plate. Method C uses a conical specimen.For Method A, the rubber-to-metal bonded specimen is pulled […] Read more

Compression Test

ASTM D395 covers three test methods for determining the compression set of rubber compounds. Test Method A uses constant force, Test Method B uses constant deflection, and Test Method C accounts for material hardness. These are applicable to rubber used in machinery mountings, vibration dampers, and seals.Standard test specimens are cylinders 29mm in diameter and […] Read more

Standard Test Method for Steady-State Heat Flux Measurements and Thermal Transmission Properties by Means of the Guarded-Hot-Plate Apparatus

This test evaluates the standard test method for steady-state heat flux measurements and thermal transmission properties by means of the guarded-hot-plate apparatus of material specimens as specified in ASTM C177. The test is performed in accordance with the procedures defined in the standard to verify compliance with the applicable requirements.Test specimens are prepared and conditioned […] Read more

Mandrel Test

Section 6.3 of ASTM B470 covers the mandrel test for Type III (heavy bonding) bonded copper conductors. The conductor is wrapped six close turns over a mandrel of size specified in Table 3.After wrapping, the conductor is slipped off the end of the mandrel for examination. No separation of strands shall be visible to the […] Read more

Fraying

Section 6.2 of ASTM B470 covers the fraying test for bonded copper conductors used in hookup wire. The conductor, cut square at the end, is inserted into a blind hole of specified size and depth.The edge of the hole is broken to no more than 1/64 inch radius. The conductor is bent 90 degrees over […] Read more

Resistance Change with Temperature

Section 10 of ASTM B344 covers the accelerated life test performed in accordance with ASTM B76. This test evaluates the long-term oxidation resistance and durability of nickel-chromium alloys at elevated temperatures.The accelerated life test subjects the wire to repeated heating and cooling cycles under controlled conditions to simulate the service life of an electrical heating […] Read more

Tolerance on Electrical Resistance per Unit Length

Section 9 of ASTM B344 covers the test for change of resistance with temperature, performed per ASTM B70. This test measures how the alloy’s resistance varies with temperature.For electrical heating elements, stability of resistance at operating temperature is critical for consistent heat output. The test characterizes the resistance behavior across the operating temperature range.Determination is […] Read more

Physical Requirements

Section 5 of ASTM B344 covers the physical requirements for nickel-chromium and nickel-chromium-iron alloy wire for electrical heating elements. The material must be thoroughly and uniformly annealed.Wire of size 0.0035 inch (No. 39 AWG) and larger must meet a minimum elongation of 20% in a 10-inch gauge length. Wire from 0.0031 inch to 0.002 inch […] Read more

Continuity of Coating – Silver

Section 8.4 of ASTM B298 covers the continuity of coating test for silver-coated soft or annealed copper wire. This test verifies that the silver coating is continuous without bare spots or discontinuities.The silver coating classes range from Class A (minimum 1.25% by weight) to Class E (minimum 10.00% by weight). The continuity test ensures complete […] Read more

Enable Coatings

Section 13 of ASTM B267 covers the thermoelectric power test for resistance wire. This measures the thermal electromotive force generated at junctions between the resistance wire alloy and copper.Thermoelectric power (thermoEMF) is measured in accordance with ASTM B77. This property is important for wire-wound resistors used in precision circuits where parasitic thermoelectric voltages can introduce […] Read more

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