What are overmolded parts and How to manufacture them?

November 25, 2021

Choosing Overmolded parts for milling at home

The selection or manufacture of Overmolded parts for a home milling machine will completely determine its accuracy in the future. Even the most advanced software only issues commands to the control drives and the spindle, and the accuracy of the milling work is determined solely by mechanics.

Overmolded parts Requirements

First, you should decide for what purposes a milling machine is purchased or manufactured, which will serve as a guideline for the requirements imposed on it:

Types of processed materials

In most cases, home CNC or manual milling machines are designed to work with wood and plastics, much less often with aluminum or bronze. It is better to carry out processing on professional equipment.

The maximum size of the Overmolded parts

From an economic point of view, the size of the workpiece roughly equal to the A4 format is easy to consider optimal from an economic point of view. This will make it relatively easy to pick up or buy guides, and the rigidity of the table even when it makes of thin metal.

Overmolded parts at the same time, if it plans to process only soft plastics or wood, then the size of the table, and accordingly the details, is easy to significantly increase. We must not forget that the price for metal structures of the table and guides, in this case, will increase significantly;

Overmolded parts Performance based on spindle power

From 60 W and more, but 600-800 W is easy to consider optimal. More powerful Overmolded parts equipped with reinforced bearings, which will increase processing accuracy.

Possibility of quick changeover for the manufacture of various parts. This indicator determines by the software common and the capabilities of the control unit. It is always advisable to buy the latest versions of the software, but if you plan to borrow processing programs from the outside, then its compatibility with those available from partners is much more important.  

Having decided on these indicators and comparing the result with your financial capabilities, you can select a finished machine or purchase separate parts for self-assembly. It is highly desirable to equip the machine with a chip sucker, especially if it plans to be common in a residential area.

Overmolded parts Errors in metal turning

Machining a part on a lathe

Even though modern equipment for metalworking by Overmolded parts distinguishes by its high quality and technical characteristics, as well as excellent functionality, it is simply impossible to achieve the most accurate (absolute) dimensions, no matter what over-molding tool and precise measuring instruments are common.

In this material, we will consider the most common causes of dimensional errors that arise during metal over-molding.

Overmolded parts Errors due to metalworking equipment

As a rule, deviations from the accuracy parameters during the assembly of metal-over molding equipment, as well as the wear of its assemblies and elements, can significantly affect the dimensional accuracy and geometry of the processed products, this is especially important in the manufacture of elements for metal structures with a complex configuration.

The most common error when machining parts on a lathe is the wrong tap. This occurs due to the installation of tailstock (there is no necessary alignment between the head and tailstock of the machine).

Overmolded parts insufficient accuracy

Often, dimensional errors during machining appear due to malfunctions or insufficient accuracy of the clamping tools. For example, it is easy to severely deform chuck jaws, or worn-out center, or adapter sleeves designed for its installation in the tailstock.

The quality of the Overmolded parts tool and how important it is for dimensional accuracy.

The sharpening of over-molding tools depends on the accuracy of the machined parts. For example, the width of the groove, which comes with a special measuring cutter, is accurate and even only if the over-molding tool sharpens correctly. Also, the accuracy of metal over-molding directly depends on the correct installation of the tool in the working position.

Overmolded parts don’t use it

Do not use worn-out over-molding tools for high-quality and accurate processing of products. Adapter sleeves during drilling, the exit diameter is easy to much larger than at the start of machining.

Because of this, the part receives a non-standard size, which affects the subsequent quality of the finished product for which it is common, for example, metal structures, the prices for which are currently available for both business and individuals.


Another important factor that can cause errors in turning is the incorrect use of the measuring tool or its inaccuracy.

Tips for fine machining of steel

Small parts

Small-sized, are parts with a diameter of up to 40 mm. Products of such a modest size have several difficulties in mechanical processing. The main snag is the quality of the cutters, as well as the accuracy of the machine tools.

It is possible to create a high-quality small-sized part by entering all the tolerances only on high-precision machine tools. In this article, we’ll look at some helpful tips to help you with small-sized steel machining.

Overmolded parts Practical advice

The following Overmolded parts processing tips are only suitable for low alloy steel workpieces:

Vc = 100 m/min, ap = 0.15 mm, fn = 0.08 mm / rev

The start of processing should be combined with a low feed to make sure there are no shortcomings.

To keep the quality of surface treatment at a stable level, and the process of chip formation occurs evenly, then the feed rate increases.

The depth of cut must be greater than the radius at the nose of the insert. This approach ensures the lowest possible radial errors, which significantly improves the quality of the internal machining of small-sized parts.
What are overmolded parts 2021

Overmolded parts cutter importance

Each Overmolded parts tool has its own minimum rotation speed. This parameter should consider when working. Otherwise, the cut quality may deteriorate, and a significant load will fall on the cutter.

Different cutters and over-molding techniques involve the use of different oils to cool the workpiece.

Small-sized products especially carefully, the coolant supply must monitor when working with the inside of the part. Here, even the highest pressures cannot guarantee high-quality chip evacuation.


Thus, for the manufacture of a high-quality part of small size, it is necessary to have precise equipment. Also, strictly observe the established norms for the use of over-molding speeds and technologies, as well as consider the nuances described above.


Get A Quick Quote