Tensile strength 抗拉强度

Yield Stress 屈服应力

Proof Load stress弹性极限应力

Ultimate Tensile stress 极限抗拉应力

Fatigue strength 疲劳强度

Torsional Strength 抗扭强度

Hardness 硬度

Ductility 延展性

Toughness 刚性

Tensile Strength – is an expression of the maximum capacity of a particular material to stretch under tension load, prior to failure.

抗拉强度—指材料在破坏之前可以承受的最大拉伸应力

Its normally expressed in 其通常表示为:

单位: Pounds/Tons – Inch terms 磅/吨

 Kilo Newton (KN) – Metric terms 千牛

Yield Stress (Yield point) – is an expression of the theoretical point of stress (pressure) beyond which the material loses its elasticity and becomes permanently stretched.

屈服应力（屈服点）--是材料由弹性变形转变为塑性变形时的应力

Its normally expressed in其通常表示为:

单位:lbf / in – Inch terms 磅/英寸

N/mm^2 – Metric terms 牛/平方毫米

Proof Load Stress – is an expression of the minimum stress a material must achieve, prior to permanent elongation and, the stress which would be applied to test and re-measure a specific fastener to prove it had not permanently stretched and that it will carry the required load

弹性极限应力—是材料塑性变形前必须达到的最小应力，此应力应通过测试或用指定的紧固件加载来证明塑性变形前可达到的载荷。

Its normally expressed in 其通常表示为

单位:lbf / in – Inch terms

N/mm^2 – Metric terms         

Approximately between 80% and 90% of the theoretical yield stress 此值大约为理论屈服应力的80%到90%

Ultimate Tensile Stress – is the theoretical minimum point at which the material will fracture. It is expressed in the same terms as yield stress and proof load stress.

极限抗拉应力—是材料断裂的理论最小值。它可与屈服应力及弹性应力同时表述

These properties are used to calculate the Proof load and breaking load for each diameter of each grade or class of product.

这些参数用来计算不同直径、等级紧固件的标准载荷及破坏载荷

Its normally expressed in 其通常表示为

单位 : Pounds force – Inch terms

Kilo Newton (KN) – Metric terms

Fatigue Strength – is the maximum stress a fastener can withstand for a specified number of repeated cycles prior to its failure.

疲劳强度– 紧固件对规定次数循环而不破坏的最大应力

Torsional Strength – is a load usually expressed in terms of torque, at which the fastener fails by being twisted of about its axis.

抗扭强度—紧固件可承受的轴线方向的扭矩

Hardness – is a measure of material’s ability to resist abrasion and indentation. For carbon steels, Brinell and Rockwell hardness testing can be used to estimate tensile strength properties of fasteners.

硬度—用于表征材料对抗磨损和划痕的能力。对于碳钢，布氏和洛氏硬度可以用来估计紧固件的抗拉强度

Ductility – is a measure of the degree of plastic deformation that has been sustained at fracture. In other words, it is the ability of material to deform before it fractures.

延展性—用来衡量材料到破坏为止的塑性变形程度。换言之，也是材料在破坏之前可变形的能力

Toughness – is defined as a material's ability to absorb impact or shock loading. Impact strength toughness is rarely a specification requirement.

刚性—用来定义材料吸收冲击或振动载荷的能力。冲击强度刚性是很少见的规范要求。