The strength of kraft paper depends on many factors, including paper type, thickness, density and production process. Kraft paper is generally known for its properties such as abrasion, tear and stretch resistance, thus giving it higher strength in some applications.

Here are some general characteristics about the strength of kraft paper:

1. Tear resistance: Kraft paper typically has very good tear strength, meaning it resists tearing and penetration. This makes it very useful when packaging and protecting products.

2. Stretch resistance: Kraft paper also generally exhibits good stretch resistance and can withstand a certain degree of tensile stress, which makes it very practical for bundling and packaging applications.

3. Abrasion resistance: Kraft paper is also used as an abrasion resistant surface in some applications as it resists abrasion and friction.

4. Thickness and density: The strength of kraft paper is generally proportional to its thickness and density. Thicker kraft papers generally have higher strength.

5. Wet strength: The strength of kraft paper may be affected by wetting, so its performance may need to be considered when used in wet conditions.

It should be noted that different manufacturers may produce different types and qualities of kraft paper, and therefore the strength characteristics will vary. If kraft paper with specific strength characteristics is required, it is advisable to speak with a supplier in order to select a product that suits your needs. Overall, kraft paper is strong enough for many packaging, craft and protective applications.