Fracture toughness in relation to the grain size and the cobalt content.

When a material is exposed to external stress, this leads to mechanical tensions. Under these circumstances, both strength and ductility of the material indicate the basis for the concept of toughness. In other words, toughness is defined as the capacity to resist fracture or rupture growth. “Palmqvist Method” is frequently applied to determine the toughness value, KIC.

Please specify as follows for ordering:

*Materials of wire,Low Carbon Steel.Medium Carbon Steel.High Carbon Steel.Stainless Steel.Brass.Aluminium.Iron.Optimum with Code of Materials.

*Head Styles,please specify when head with washer.

*Hollow screw,please specify when used for hollow screw.

*Triangle screw,please specify the wire diameter when used for triangle screw.

*Non-standard screw,please attach drawings or samples when used for non-standard screw.

Common questions in using screw and nut mold:

1. The master worker have the experience of mold and structural design , analyzing the reason of  the unreasonable distribution of die stress ratio and deformation.

2.The cleanliness of the mold, the inner hole finish is not enough.

3.The rigidity of shell sleeve material, the heat resistance,and the heat treatment hardness are unreasonable.

4.In order to save the cost of production, they selected poor quality tungsten carbide steel and wire rod, alloy specifications and steal material nailing serious wheels are unreasonable.

5.The collider is not appropriate, without replacing lubricants and checking machine long-term.

6.The master worker of adjusting must have high technical level.