This process is done using a Spring Coiler or CNC spring coiler which is a mechanical spring making machine. The spring technician performs what is known in the industry as a "set-up" on the machine to prepare the spring machine for creating a specific type of spring. This type of spring machine is used to make compression springs, extensions spring and torsion springs. This process involves feeding the wire into a set of rollers that pulls the spring wire into the wire guides then comes into contact with a coiling point or points which coils the wire backwards forming it into a coil or a pigtail, thus the term "coiling the spring" was born. Please see the picture to the right for a visual explanation.
This process is done using a spring former or CNC spring former machine which is also a mechanized spring making machine. This type of machine is used to make tension springs, torsion springs, double torsion springs and wire forms. Spring manufacturers can use it to make compression springs but is is not efficient for that. The difference from a spring former machine versus a spring coiler is that the spring former has 6 to 8 tooling slides on the face of the machine enabling it to perform various bends, loops hooks,radius and various wire shapes on the ends of the springs or on the wire form itself. It is a extremely versatile machine. Please see the picture to the right for a visual explanation.
This process uses a CNC wire bender which is computer numerically controlled mechanical wire bending machine. The Wire bender is used to manufacture wire forms. This machine feeds the wire into a set of rollers that pulls the wire into the wire guides then pushes it into a movable tooling head. This tooling head can be made to perform bends, u-shapes, radius, zig zags as well as a large variety of other wire bends. The innovative feature of this machine is that the tooling head can swivel and rotate 360 degrees meaning your wire form can have bends on many different planes. Please see the picture to the right for a visual explanation.
When springs are manufactured they need to be stress relieved (heat treated) so the spring can retain its memory. With out heat treating the springs will not hold their elastic shape and not have the bounce we require from the spring. For this reason a spring manufacturer must heat treat or stress relieve every spring manufactured . When heat treating a spring the spring manufacturer must heat treat the spring to a specific temperature for a specific amount of time according to the type of spring wire they use. For example if the spring was made out of music wire then the proper stress relief or heat treat would be 500 degrees fahrenheit for 30 minutes time, if the spring is made out of 302 stainless steel the proper heat treat is 600 to 650 degrees fahrenheit for 30 minutes time. The most modern equipment used is a conveyer belt oven. This oven is placed next to the spring machine so the springs come down a slide and fall into the mouth of the conveyer belt oven. The springs move along the conveyer belt into the furnace section of the oven getting the proper heat treat, then come off the convey belt on the other side and fall into a receiving box for cooling down.
Spring wire is used to manufacture springs. This spring wire on a hardness scale is very hard. Typically on the hardness scale their is 1/4 hard, 1/2 hard, 3/4 hard and full hard. With spring wire it is above full hard meaning it is a very hard material. The reason is that spring wire needs to have memory to be elastic so it can bounce back to it's original length. The tensile strengths of spring wire can be found on our properties of common springs material pageproperties of common springs material page.
