Your Trustable Partner In Gear parts Manufacturing

Gear Parts & Mold Manufacturing Capabilities

  • Experienced mold-flow analysis on gear parts mold.
  • Statistically capable extension of the molding and manufacturing process.
  • State-of-the-art software and equipment.
  • All molds are CMM validated.
  • Cleanroom Injection molding.

Manufacturing Your Precision Gear parts with Injection Mold Expert

Assembly & Testing for Gear parts
Precise molding process and highly sophisticated ERP system from SAP Automatic robot operation system.
Gear parts injection molding
Equipped with a batch of high quality Injection machine from 60 tons to 200 tons to provide world class injection molding machine service.
Gear parts Quality Control
The quality inspection guide is tailored to meet the specific requirements of the customer. Detailed inspection throughout the gear parts to ensure accuracy.

One-Stop Solution for Your Injection Gear Parts Manufacturing

Product Development

From design to completion, our design engineers will assist you in each step of gear parts development.

Mold Design

Customized mold design for each gear part, we have the expertise and the latest engineering technology to manufacture high-quality molds for gear parts.

Mold Manufacturing

We construct mold with manufacturability in mind. We can review your plastic gear part design to ensure superior fit, form, and function, while at the same time minimizing gear parts cost and gear mold cost.

Gear Parts Injection Molding

Statistically capable extension of the molding and mold manufacturing process in gear parts.

Assembly & Packaging

Continuous assembly and packaging improvements help us get gear parts to our customers.

Why Kemal can be Your Reliable Gear Parts Supplier?

  • Keep the feedback system from part design to gear parts production
  • The internal standards on all aspects that exceed customers
  • Scientific Molding Process in Gear Parts
  • Provide technical guidance and training for customers
  • Rich Experience Team on Your Precision Injection molds

Experienced on Precision Gear Mold Manufacturing

  • Gear Mold
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Kemal Molded your Plastic injection Gear Parts

Kemal has a tool room of 6,500 square meters, capable of manufacturing and maintaining all types of gear injection molds. Our factory has more than 25 years of experience in building gear precision molds, from prototype gear molds to high volume production gear molds. precision tolerance gear mold is produced by using state-of-the-art Wire-cut EDM, and Precision EDM equipment. Enables us to deliver the gear molds to the customer in the shortest t time.

Kemal could provide services and expertise in the design, development, mold manufacturing, testing, and plastic injection molding of gear parts. Experience in European and North American markets and a strong record of cooperation, as well as recommendations from established customers, have enabled some new customers to order gear parts molds in a short time.

Professional after-sales technical service in English wins established customers to continue cooperation when they need gear molds. Please send inquiries immediately and the quotation will be sent within 24 hours.




As plastic gear parts have the advantages of low transmission noise, the ability to absorb vibration, self-lubrication, and high productivity in mold processing, etc. In recent years, the application of plastic gear parts in the gear industry will be more and more widely, becoming a worldwide trend. In the application range of gear molds and plastic gear parts, the demand is relatively large and the market potential is huge.


1.What is the gear parts?

2.What are the types of gear parts?

3.What is the application of gear parts?

4.What is the material of gear parts?

5.What is the material property of gear parts?

6.What is the advantage of gear parts?

7.What is the precision gear parts?

8.What is the key point to design the cavity of gear molds?

9.What is the common steel for gear molds?

10.How to design the gate location of gear molds?

11.What are the core components of a gear mold?

12.How can Kemal design a gear mold?

12.How to machine the gear molds?

13. Where to gate the gear molds?

14.How can Kemal machine a gear mold?

15.How to choose injection machines for gear molds?

16.How to do the first trial of gear molds?

17.How to measure the gear parts?

18.How to maintain the gear molds?

19.How can Kemal ensure the quality of my gear project?

20.How do I get a quote for a gear mold?


1.What is the gear parts?

The plastic gear part is one of the gears, mainly used for transmission, and its material is plastic.

Gear parts are mechanical parts with teeth that can mesh with each other, and it is extremely widely used in mechanical transmission and the entire mechanical field. Modern gear technology has reached: gear modulus O.004 ~ 100 mm; gear diameter from 1 mm ~ 150 m; transmission power up to 100,000 kilowatts; speed up to 100,000 rpm; the highest circumferential speed of 300 m / s.


2.What are the types of gear parts?

Manufacturing a variety of plastic gears are spur gears, helical gears, worm gears, crown gears, bevel gears, planetary gears, tooth boxes, damping gears, involute gears, cycloidal gears, circular arc gears and other gears of various sizes and moduli, non-standard quirky gears, multi-process with complex over-molded gears, foreign standard low-noise gears, etc.

Selecting the combination of gears with various process parameters can effectively achieve the designed use requirements, such as deceleration, speed increase, timing, energy conversion, positioning, and fixed-point functions.

3.What is the application of gear parts?

The gear parts are used in various industries such as micromotors, electronic products, auto parts, household appliances, office supplies, toys, crafts, etc. Such as in-car mirrors, headlight regulators, timers, micro motors, reducers, printers, fax machines, cameras, DVD movements, shredders, copiers, massagers, toy movements, instruments, medical devices, vacuum cleaners, automatic coffee machines, and other products, are used in different gear combinations.

4.What is the material of gear parts?

The most common materials used for plastic gears are polyoxymethylene (POM), nylon (PA66, etc). POM is a side chain free, high density, and high crystallinity linear polymer with excellent all-round properties. The smooth, glossy, hard, and dense material (yellowish or white) can be used for long periods of time at temperatures ranging from -40 to 100c. It is also more wear-resistant and self-lubricating than most engineering plastics, and it has good resistance to oils and peroxides. POM has a tensile strength of 70″ MPa, low water absorption, dimensional stability, and high gloss. POM is a highly crystalline resin and is the toughest of the thermoplastic resins. It has heat resistance, bending strength, high fatigue resistance, excellent wear resistance, and electrical properties.

PA66 plastic has a high melting point among polyamide materials (a semi-crystalline material) and retains its strength and stiffness at higher temperatures.

5.What is the material property of gear parts?

(1). ABS plastic and LDPE materials usually do not meet the performance requirements of plastic gears in terms of lubricating properties, fatigue resistance, dimensional stability as well as heat and chemical resistance. However, they are also used in the field of low-grade sporting transmission gears such as various toys.

(2). PC (polycarbonate) has excellent impact and weather resistance, high hardness, low shrinkage, and dimensional stability. However, the self-wetting properties, chemical resistance and fatigue resistance of polycarbonate are poor. This material is colorless and transparent, easy to color, in the instrumentation precision gear parts and craft decorations, still more applications.

(3). POM (polyformaldehyde) as a gear part most commonly used, the most important thermoplastic engineering plastics has a history of more than 40 years. Because polyformaldehyde moisture absorption is particularly small, can ensure that the gear parts for a long time the dimensional stability and in a wider temperature range of fatigue resistance, corrosion resistance, and other excellent characteristics and self-lubricating properties, has been the single preferred engineering plastics in plastic gear parts.

(4). PPA (polyp-phenylene terephthalamide) has high heat deformation stability, can be in a higher, wider temperature range and high humidity environment, maintain its superior mechanical strength, hardness, fatigue resistance and creep resistance. It can work under high temperature and high humidity conditions that some PA6 and PA66 gear parts cannot withstand.

(5). PA (nylon) has the advantages of good toughness and durability and is another common engineering plastic for gear parts. However, nylon is highly hygroscopic and can cause changes in the performance and dimensions of plastic parts. Therefore, nylon is not suitable for precision gear parts.

(6). LCP (liquid crystal polymer) has long been successfully used in injection molding of micro-fine plastic gears with a small modulus. This gear part has good dimensional stability, high chemical resistance, and low molding shrinkage. This material is commonly used for molding micro plastic gears for watches.

(7). PPS (polyphenylene sulfide) has high hardness, dimensional stability, fatigue, and chemical resistance and characteristics as well as long-term use temperature up to 200℃ or more. Polyphenylene sulfide gear parts have been extended to automotive, special fluid pumps, and other gear transmissions work very demanding applications.

(8). PEEK (polyether ether ketone) and modified polymers have been successfully applied to high-performance plastics in heavily loaded power transmission gear parts. These materials have high-temperature resistance, high overall mechanical properties, wear, and chemical resistance, and other characteristics, is the top work plastic in today’s molded gear parts.

(9). PBT (polyester) can be molded to produce gear parts with a very smooth surface, with a maximum operating temperature of 150℃ for unfilled modified moldings and up to 170℃ for glass fiber reinforced moldings. The gear parts have good transmission properties and are often used in gear construction.

6.What is the advantage of gear parts?

(1) The freedom of design of plastic gear parts ensures more efficient gear manufacture than metal molding. Products such as internal gears, gear sets, and worm gears can be molded in plastic. Plastic gear parts have a wider field of application than metal gear products and they are therefore driving the development of gears to withstand higher loads and transmit more power.

(2) Plastic gear parts are also an important part of meeting the requirements for low silent operation, which requires the availability of high precision, new tooth shapes, and materials with excellent lubricity or flexibility.

(3) Gear parts made of plastic generally do not require secondary processing and therefore guarantee a 50% to 90% reduction in cost compared to stamped and machined metal gears. Plastic gear parts are lighter and more inert than metal gear parts and can be used in environments where metal gears are prone to corrosion and degradation, such as water meters and control of chemical equipment.

(4) Compared to metal gear parts, plastic gear parts can be deflected to absorb the effects of shock loads and are better able to disperse local load variations caused by shaft deflection and misalignment. The inherent lubrication characteristics of many plastics make them ideal gear materials for printers, toys, and other low load running mechanisms, excluding lubricants. In addition to running in a dry environment, gear parts can also be lubricated with grease or oil.

7.What is the precision of gear parts?

Precision gear parts refer to very high requirements in terms of parameters and performance. Parameters include top circle outer diameter, root circle outer diameter, module, index circle diameter (also known as the common normal), index circle tooth thickness, pressure angle, skew angle, tooth runout tolerance, etc.; performance includes the choice of materials and other assembly dimensional accuracy requirements.

Precision gear parts are graded in terms of accuracy, the higher the level the more precise the national standard, the smaller the level the more precise the Japanese standard. In JIS standard, most precision molding factories can only do 4 or 5-grade gears, can do 3-grade plastic gears is already quite a high level.

8.What is the key point to design the cavity of gear molds?

There are two main points: one is the plastic shrinkage rate is difficult to be precise: in the plastic gear molding process, the plastic from the granular solid raw materials through the high-temperature transformation into molten plastic liquid Hugh, and then after cooling molding solid plastic gear parts. The shrinkage rate of plastic in this process is a range of values, and it is difficult to determine the shrinkage rate of plastic accurately; the second is the non-linear shrinkage calculation of the mold cavity: for involute small modulus plastic gear molds, the mold cavity is an imaginary gear. This imaginary gear is different from both the displacement gear and the internal gear. This imaginary gear, when shrunk, becomes the plastic gear part we want.

9.What is the common steel for gear molds?

Cavity & core: 12343 / 1.2344 HRC48-50, 718H, S136 etc.

Mold base: P20, S50C

the mold steel depends on the mold life and product quantity.

We can select the steel type according to your request.

10.How to design the gate location of gear molds?

The location of the gate has a significant impact on the accuracy of the gear mold, particularly in terms of radial runout; the distribution of the gate has a significant impact on the overall mechanical properties of the plastic gear parts. In the design of the plastic gear mold gate, if the gear part allows, it is recommended to use a three-point gating method, and the three points should be in the same arc and evenly distributed; when using a three-point balanced gating, the plastic melt will flow from the gate in a radial pattern to the surrounding area, and three fusion lines will be formed at the convergence of the flow front. At the fusion line position, the fibers are oriented parallel to the flow front. In gear parts, this results in the radial distribution of fibers at the fusion line and random distribution in the rest of the gear part. This results in a low shrinkage area along the fusion line. The difference in fiber orientation between the fusion line and the rest of the gear is less than in a single gate gear, resulting in a more accurate gear part.

11.What are the core components of a gear mold?

The core component of a plastic gear mold is the gear cavity, the structure of that depends on the profile of the tooth. The gear cavity (or core) is machined using equipment and processes that have become a major indicator of the level of a country’s modern mold making industry (referred to as the modern mold industry). Gear cavity can use EDM machine processing. If a wire cutting machine is used, the structure of the gear cavity is more complex. In order to simplify the cavity structure and improve the accuracy of the cavity, it is best to use a high precision EDM machine.

12.How can Kemal design a gear mold?

Kemal engineers have over 10 years of experience in the injection mold industry, and design the gear mold according to your request, also provide our professional suggestion. Here some points in designing the gear mold.

(1) Gating: Generally 3 or 6 points balanced gating, for miniature gears only single point pouring is usually used.

(2) Mold cavity layout: 1 to 4 cavities are common. Smaller gear parts can have 6 or 8 cavities; gears parts of different shapes can have 3 cavities. The most representative one is 4 cavities.

(3) Ejection way: Commonly there is a central cylinder and an ejector pin. For helical gears, bearings must be added to assist ejection, the bearings can be placed on the sieve pin or the core of the gear mold. As the product is small, the mold base is also small, the ejector plate generally does not need to be added in guide bushing.

(4) Parting surface block: parting surface block must be installed cylindrical parting surface block.

(5) The cavity&core and inserts are cylindrical to process to ensure the coaxiality of the product. The material is generally SKD61, hardened to HRC52~56.

13.where to gate the gear molds?

The machining of gear molds requires more attention to detail and the measuring techniques which require to achieve the precise level of measurement to ensure that the molding temperature and cooling rate within each cavity are the same for each molding run than the requirements of general molding operations.

The most common problem in precision gear machining is how to deal with symmetrical cooling of the gear and consistency between cavities.

Molds for precision gears typically have no more than four cavities. Gear tooth inserts are used to reduce the cost of secondary cutting.

Precision gear molds should be filled with a single gate at the center of the gear. Multiple gates tend to form fusion lines, altering pressure distribution and shrinkage and affecting gear tolerances. With glass fiber reinforced materials, the use of multiple gates can cause eccentric ‘collisions’ of radii due to the radial arrangement of the fibers along the weld line.

Kemal has extensive experience in designing and manufacturing precision gear molds to control deformation at the tooth groove and achieve a controlled, consistent, and uniformly shrinkable product. The temperature, injection pressure, and cooling of the precision molded surfaces are well controlled during molding.

14.How can Kemal machine a gear mold?

By using state-of-the-art equipment, Wire-cut EDM, and Precision EDM equipment. Kemal can deliver the gear mold to your hand in high precision. During the machining process. Kemal pays attention to the important step to ensure the precision of your gear parts.

(1) Gear processing: straight gear is processed with WEDM-LS, and helical gear rings are processed with gear electrode spiral, making helical gear electrodes with very high precision.

(2) The processing of the round-shaped tube position block on the parting surface requires A and B plates to be processed by WEDM-LS at the same time to ensure precise coaxial positioning.

(3) Cylindrical cavities and inserts need to be processed with internal and external cylindrical grinding machines, and the cavities of A and B plates must be processed with co-ordinate grinding machines. In cylindricity, straight roundness, verticality, and roughness to meet the requirements. To ensure the “precision” of the gear.

(4) General gear ring insert, after gear processing, the thickness of the insert is not allowed to use the grinding machine again to avoid causing transverse burrs on the gear parts surface.

(5) Polishing: gear surface and edge are not allowed polishing, the relevant roughness only through electric machining once processing to achieve.

15.How to choose injection machines for gear molds?

Factors that usually influence the choice of gear injection molding machine include product size, type of plastic, molding requirements, etc.

Mold dimensions (width, height, thickness), weight, special designs, etc.

The type and quantity of plastic to be used (single raw material or multiple plastics)

The external dimensions (length, width, height, thickness), weight, etc. of the finished injection molded product. Forming requirements, such as quality conditions, production speed, etc.

The injection molding machines for gear molds are generally vertical injection molding machines, horizontal injection molding machines, and fully automatic injection molding machines.

16.How to do the first trial of gear molds?

(1) At T1, the cooling water must be connected, gear molds and housing molds are different, due to the design structure, the cooling water can be made before T1. If the cooling water is not connected, the gear parts will be very different in size and local thermal balance, which will directly affect the crystallinity and post-shrinkage of the plastic material and the accuracy and dimensional stability of the gear parts.

(2) At T1, the first thing that needs to be ensured is the outer diameter and thickness dimensions of the gearpart, because these two dimensions are generally the ones that the mold does not have to be repaired or not repaired. As long as the first two dimensions are guaranteed and the molding conditions are stable, the other dimensions can be temporarily accepted and then completed for the second time through mold repair. In general, with a guaranteed outer diameter of the gear part, the profile lines of the individual gear will not differ significantly from the theoretical one.

17.How to measure the gear parts?

To measure the outer diameter of gear parts, digital calipers can generally be used, but for gears with 3x and 5x gear, 3 hook micrometers, and 5 hook micrometers are used. gear profiles can be fillet-projected contour lines. However, precision testing must have professional gear electronic testing equipment, the gear past samples will be mounted on the standard gear interlocking, and then enter the required gear-related parameters, the computer will automatically display the test data, including the radial runout of the gear parts and other parameters. Kemal is equipped with a three-dimensional measuring machine for precision inspection and can ensure the quality of your gear parts.

18.How to maintain the gear molds?

(1) During the formal production, no spray release agent, otherwise the gear part is not acceptable; the reason is that the lubrication of the release agent affects the gear engagement and meshing measurement, and hidden in the gear surface is not easy to wipe away, and not clean; easy to stick to the dust, affecting the accuracy of the gear parts.

(2) Mold temperature and barrel temperature is the key to ensure continuous production of gear parts with stable dimensions.

(3) As long as the gear mold is taken off from the machine, or stopped for more than 1 hour on the injection machine. the gear mold must be sprayed with the anti-rust agent; check whether it has been sprayed with the anti-rust agent before dropping from the machine. Once the gear ring insert is severely rusted on the gear surface, there is basically no room for repair, as it is a precision mold.

(4) If the O-ring leaks water on the gear surface, it is normal that it cannot be wiped with a cloth. The better way is to use filtered air to blow it clean, then dry it with a torch and spray it with rust inhibitor before dropping it from the machine.

19.How can Kemal ensure the quality of my gear project?

Kemal’s experienced engineering team will review your plastic gear part design and optimize the structure and performance of your gear parts. we have the latest engineering technology to produce high-quality gear molds that will minimize the mold costs of your gear parts.

besides, we assign a project engineer to manage your gear project before it begins. The project engineer manages all project activities. project management reports follow your company’s format and keep you updated, such as weekly project updates with photos or videos, timely phone or video meetings to discuss technical issues until samples are successful and the mold is completed, more importantly, the project engineer will standby to resolve any follow-up issues after the mold has been shipped.


20.How do I get a quote for a gear mold?

(1)If you have the gear drawing, you can send us the drawing and request info:

  • 2D ( DWG, PDF, JPG)
  • 3D (STP, STEP, IGS, X_T)
  • Material type.
  • Surface Treatment Requirement.
  • Parts annual volume or mold life.
  • Mold cavity.

(2) If you don’t have the gear drawing, you can send us the sample:

we can make a drawing (1-2 days) according to your sample and send it for your checking and approval before mold manufacturing.

(3) If No drawing and No sample. you can provide the estimated dimension of your gear part.

we can evaluate and provide a proposal for you.


Send Your Inquiry Today