Manual

®
Model No. AP-8214A 012-13282A Introduction
3
Test Coupon Specifications
The data below are intended as a general guide only and do not necessarily represent results that may be obtained.
The units for tensile strength and modulus of elasticity are megapascals (MPa or 10
6
N/m
2
) and pounds per square
inch (psi).
AP-8222 Plastic Test Coupons
AP-8223 Metal Test Coupons
Theory.
A stress-strain tensile test measures the amount of stretching force
applied to a sample of material, and the amount of stretch of a mate-
rial. Stress (σ) is the ratio of force (F) per unit of cross-sectional area
(A). Strain (ε) is the ratio of the change of length (l) compared to the
original length (L). A stress-strain curve is a graphical representation
of the load applied and the deformation of the sample. The curve var-
ies from material to material.
Ductile materials like metal have a linear stress-strain relationship up
to a point. The slope of the linear part of the stress-strain curve is
called “Young’s modulus” or the modulus of elasticity (E) and is a
property used to characterize materials.
Item HIPS nylon 6 (+ 15% glass) ABS polypropylene
Color code orange black blue white
Cross-sectional area 2.482 mm
2
2.482 mm
2
2.482 mm
2
2.482 mm
2
Tensile strength 23 MPa/
3410 psi
98 MPa/
14000 psi
47 MPa/
6800 psi
34 MPa/
4900 psi
Tensile elongation 40% 2.5% 20% 9%
Modulus of elasticity 2000 MPa/
280000 psi
2900 MPa/
420000 psi
2300 MPa/
380000 psi
1900 MPa/
239000 psi
Item cold-rolled steel annealed steel aluminum brass (thin) brass (thick)
Cross-sectional area 0.303 mm
2
0.303 mm
2
0.303 mm
2
0.303 mm
2
0.506 mm
2
Tensile strength 620 MPa/
90,000 psi
300 MPa/
44,000 psi
145 MPa/
21,000 psi
430 MPa/
44,000 psi
430 MPa/
44,000 psi
Tensile elongation none 42-45% 6% 25% 25%
Modulus of elasticity 200,000 MPa/
29,000,000 psi
200,000 MPa/
29,000,000 psi
69,000 MPa/
10,000,000 psi
117,000 MPa/
17,000,000 psi
117,000 MPa/
17,000,000 psi
Fig. 4: Stress-Strain curve