How To Make A Bolt

Manufacturing a bolt is typically a Cold Heading process. Cold Heading essentially means ramming a piece of steel into a die or a die into a piece of steel in order to shape it in the desired fashion. The shapes can be quite complicated or relatively simple depending on what type of finished product is desired. There's a good article on my official website that shows specifically how thats done as well.

In any case while surfing the web I ran across this video on You Tube.

Licensed Thread Forms / Plastite and PT

I often get calls from people looking for plastic thread forming screws and generically assume that all screws are created equal. It's probably better to say that every screw thread form has a purpose.

Two innovators of thread design are EJOT and Reminc. EJOT developed the PT Screw and Reminc developed the Plastite. Both license their designs to screw manufacturers around the world. They constantly develop new products as well to protect their patents and their profits. Manufacturers like Semblex produce these licenced products.

The PT screw has a very thin 30 degree angle cross section of thread and a recess to allow for material displacement in the root of the thread.

The Plastite 48-2 has a trilobular thread pattern, a 48 degree angle cross section of thread and a twin lead.

The PT screw is intended to reduce hoop stress in the boss that the screw will be used on. Because of this a thinner boss may be utilized which speeds cycle times on plastic injection molding machines. This is a big money saver for a company like Qualcomm. The latest development of the PT screw is the Duro PT.

The Plastite 48-2 has a thread form that reduces heat when driving the screw and provides for a reduction stripping while increasing drive torque. The twin lead means the screw seats very fast because it requires half the revolutions. This is generally a good thing for softer plastics. There is also a Plastite 45 and Plastite 60-1 thread pattern.

Rotational Mold Inserts / Roto Mold Inserts

If you've ever seen a Rotational Mold Machine it's a sight you wont forget because they are not only big but they look kind of like a large gyroscope.

Basically a Rotational Mold Machine operates by spinning the mold while molten plastic is moved by centrifugal force into the far reaches of the mold. Plastic kayak's, large plastic bins and storage units are examples of products formed by Rotational Molding.

Oftentimes a fastener is desired on the product to attach handles, knobs, closures etc. So like a molded in insert, the rotational mold insert is installed in place on the removable stud attached to the mold. When the finished product is removed from the mold the fastener is then in place. The dumbbell shape is common for rotational molding because it allows for a large gap for the plastic to fill in to provide excellent retention. The rotational mold process doesn't always allow for a high degree of precision regarding the wall thickness and placement of the plastic because of the use of centrifugal force to move the plastic.

Apex Fasteners provides a variety of Rotational Mold inserts in both brass and stainless steel. We begin with both hex and square bar stock to optimize retention. We can also manufacture specials to print. Please follow the link below for more specific information:
http://www.apexfasteners.com/Rotational_Mold_Inserts.htm

Molded In Inserts

Apex Fasteners features a variety of Molded In Inserts. Typical assembly requires that the insert be screwed onto a post inside the mold cavity and then plastic or in some cases metal is injected into the mold. On cooling the screw or post in the mold is removed leaving strong threads positioned precisely where they should be.

Typically Molded In Inserts are blind so that the injected plastic will not enter the threads. The inserts are manufactured out of brass or stainless steel but we can produce special inserts in unique materials on request.

All of our inserts are available in both standard and metric threads. Of note is the available thread depths and we differentiate our part numbers based on how many full threads the insert has available.

For additional information and the specific sizes we carry please look into our website: http://www.apexfasteners.com/Molded_In_Inserts.htm