Tensile Strength

ASTM E6, Section 37 - Terminology - The maximum tensile stress that a material is capable of sustaining. Tensile strength is calculated from the maximum load during a tension test carried to rupture and the original cross sectional area of the specimen.

Procedural specifications - ASTM A370, ASTM E8

Size Tolerance

Allowed maximum deviation from a nominal diameter. Usually expressed as both plus and minus and in the same units with the same precision as the nominal diameter. Most ASTM standards specify the tolerance as "absolute" as defined in ASTM E29.

Roundness Tolerance

The allowed maximum range in size readings at any given point in the wire. The roundness tolerance is usually specified as one half of the size tolerance.

Wrap Test

A wire sample is coiled in a closely spaced helix around a mandrel of specified diameter. After wrapping, the specimen is examined for cracks. The sample shall be considered to have failed if any cracks occur in the wire after the first complete turn.

Procedural Specification - ASTM A370 (Annex A4.7)

Coiling Test

This test is used to determine if imperfections are present to the extent that they may cause cracking or spitting during spring coiling and spring extension. A coil of specified length is close-wound on an arbor of a specified diameter. The closed coil is then stretched to a specified permanent increase in length and examined for uniformity of pitch with no splits or fractures.

Procedural Specification - ASTM A370 (Annex A4.8)

Bend Test

A test piece is bent through a specified angle around a specified mandrel. When complete fracture does not occur. the convex side of the sample is examined for cracks.

Procedural Specification - ASTM E290

Torsion Test

A straight length of wire is twisted in a fixture until fracture occurs. The fracture surface should be perpendicular to the axis of the wire and free from cracks or other injurious flaw.

Procedural Specification - ASTM E558