(1) variable mold nitrogen spring outside diameter, variable pitch and variable wire diameter (three-variable) suspension mold nitrogen spring to achieve non-molding processing. Since the development of precision die nitrogen springs, conical steel rods have been used for winding on CNC lathes, but the finished products and prices are not ideal. It is necessary to control the roll speed and drawing force under the heating state through the spring coiling machine to obtain the required cone shape and quench with processing waste heat.

(2) The nitrogen spring rod of the hollow stable mold is made of low carbon boron steel plate, rolled and welded.

(3) The torsion bar is made of high-purity 45 steel, which obtains high surface hardness and large residual compressive stress after high-frequency quenching, thus improving fatigue life and anti-relaxation ability.

(4) The nitrogen spring of the die widely used in electronic products is basically formed by stamping and automatic bending. At present, it is mainly to develop the bonding technology of composite materials.

(5) The valve die nitrogen spring mainly develops multi-stage shot peening and liquid nitriding processes to improve the surface residual compressive stress and improve fatigue life.