Selecting correct tolerance for machined components

Concerning the tolerance of machined components. 

Generally, the dimensional tolerance is determined first.

And then the shape and position tolerance is determined. When we design the machined components, for the reasonable tolerance, we should consider the function needs first, the second is the processing technology.

The last is the assembly and maintenance technology.

For example, assembly hole and shaft, it is not only a round hole and shaft, can be square,but we usually use round, because the convenient processing. Traditional processing methods such as turning, milling, drilling and grinding,most of the circular processing. Now with the popularity of laser cutting and wire cutting,the application of special-shaped hole is also more.At the same tolerance level,the processing cost of square hole is higher than round hole.

Since the traditional method of processing is circular processing, the choice of hole and shaft will have a basic hole system and basic shaft system.

Generally, we can get hole by drilling, reaming, and milling. For convenient machining, we should choose to have readily available tools (drill, reamer,cutter) size, such as the diameter 14mm of cutting tool are very rare, we can choose 12mm,15mm or 16mm diameter of cutting tools,which is a conveninet purchase specifications. In this way, the manufacturing cost is very low. For example,choose diameter 30mm not 27mm, although your computing needs 27mm.

The fit of hole and shaft includes clearance fit, transition fit and interference fit.

Learn more about tolerance of machined components.

know more about CNC machining parts supplier in China

Do you know how many CNC machining parts supplier in China?

Only in Dongguan City, which is close to Hongkong in southern China. In 2022, there are almost 9600 machining plants in operation. how to get a reliable one from so many machining suppliers?

No matter the lower price, I think another thing is more important for choosing CNC machining parts supplier, that is who can help you solve some questions as below.

1.Delayed delivery, orders are not followed up in time.

2.Product quality is unstable, poor appearance.

3.Production strength is not enough to achieve the expected results.

4.Low service efficiency, slow response.

SYM Precision machining team can solve all above issues for you.

1. Production ability

With over 25 years of machining experience,we had provided various custom machined parts according to customer's needs.

2. Equipment advantage

Introducing a number of advanced automated production equipment, accurate measuring instruments.Continuosly optimize and improve the production process to meet customer one-stop purchasing needs.

3. Quality Assurance

Professional quality inspectors with years of experience in quality control, from incoming meterial inspection to quality confirmation before shipment. Provide you high quality machined parts.

4.No worries after sale

We have a sales service team, follow up and deal with any problems you encounter, reply within 24 hours, provide preofessional and perfect solutions.

One-stop machining service at SYM.

CNC milling

CNC turning

EDM | wire cutting

Grinding

heat-treatment | surface finish

Mechanical assemblies

Material: AL6061-T6 

Finish: Red anodize

Material: AL6082

Finish: bead blasting

Material: SS303

Process: 5 Axis CNC machining

Related article :  CNC Machining Factory in China

How to choosing a reliable CNC machining supplier?

Are you troubled by the following questions when choosing a reliable CNC machining supplier?

1.Production strength is not enough to achieve the expected results

2.Product quality is unstable

3.Delayed delivery

4.Orders are not followed up in time

5.Low service efficiency

SYM CNC machining services can solve all above issues for you.

----- With over 25 years of machining experience,we had provided various custom machined parts according to customer's needs.

----- Full equipment,professional technical team.

----- Reliable quality, fast delivery.

----- No worries after sale, providing perfect after-sales service.

More details, please check SYM CNC machining services.

Selecting correct tolerance for machined parts

Selecting correct tolerance of the machined parts during our design work, that is very useful for high efficient production.

Concerning the tolerance of machined parts, generally, the dimensional tolerance is determined first, and then the shape and position tolerance is determined. 

When we design the machined components, for the reasonable tolerance, we should consider the function needs first, the second is the processing technology, the last is the assembly and maintenance technology.

The fit of hole and shaft includes clearance fit,transition fit and interference fit.

1) If one-way intermittent operation and rotation displacement requires with low precision, low speed with flat key match, we can choose clearance fit, but need to have two screw at 90 degrees set positioning.

2) If it is one-way intermittent rotation, or forward and reverse motion, choose the transition fit, but also need to have a set screw.

3) If it is to transfer large torque,then choose interference fit,which usually requires pressure assembly or hot sleeve assembly.

The form and position tolerance is the supplement of the dimensional tolerance, so the selection of the tolerance zone should be less than the dimensional tolerance.

A machined part, the width of tolerance is 0.2mm, if require the parallelism of the both sides surface, it requires less than 0.2mm. Most of the time, the width of the tolerance request is not high, but the parallelism requirement is high. may is 0.05mm, so that the parallel is very important,usually influnece on assembly.

Advanced CNC machining parts factories

Advanced cnc machining parts factories have lots of cnc machine,they have advanced technologies.They always can produce superior quality machined parts.That's because they are proficient in the methods and skills of CNC machining.

1.Programming skills

The demand of CNC machining parts is very high.there are two aspects should be fully considered when programming.

One is the processing sequence,and the other is parameters such as speed,feed,and depth of cut.

The processing sequence is generally drilling first, then flat end. This can prevent material shrinkage during drilling. Rough machining first, then precise machining.First machining with large tolerances and final machining with small tolerance.

According to the hardness of the material,choosing a reasonable speed, feed and depth of cut.

Carbon steel materials: choosing high speed,high feed,and large depth of cut.

Carbide materials: choosing low speed,low feed, and small depth of cut.

Titanium alloys materials: choosing low speed, high feed, and small depth of cut.

2.Direct tool setting method

First select the center of the right end of the machined part as the tool setting point, and set it as the zero point.After the machine tool returns to the origin, each tool that needs to be used is set at the zero point.

This direct tool setting method, even if the machining center is powered off, the tool setting value will not be changed after the power is turned on again and restarted.

3.Debugging Tips

In order to prevent errors in the program and mistakes in tool setting,after the parts are programmed, they need to be tested and debugged after the tool is adjusted.

First, carry out simulation processing,and confirm that the program and tool setting are correct.

Second,processing the first part.

Finally,the debugging is over after confirming that the first part is qualified.

4.Tool collision prevention tips

The collision of the tool is a great damage to the accuracy of the equipment.As long as the operator is careful and know methods of anti-collision,collisions can be completely prevented and avoided.

There are only three reasons for tool collision.

1) The input error of the diameter and length of the tool.

2) The input error of dimensions of the machined parts and the initial position of the machined parts.

3) The machined parts coordinate system of the machining center is set incorrectly, or the machine zero point is reset in the machining process.

In order to avoid the collision above, the operator should pay attention more in machining process, observe whether the machine tool has abnormal movement, whether there is spark,whether there is burnt smell. If an abnormal situation is found, the program should be stopped immediately,and start to work after the problem is solved.

Choosing good quality precision machining service

2020,affected by the covid-19, in the current economic climate we have to improve our ability to resist risks, so choosing good quality preicsion machining service is very important for your whole mechanical assembly projects.

SYM precision machining focus on custom machining 23 years, to support you get good quality precision machining service. Such as Turning, Milling, CNC machining, 5-Axis machining, grinding, wire cutting and EDM.

There are 3 machining team to meet all kinds of  your machining needs.

1. Machining Team 1

The main workis for some samples development, rapid prototyping parts.

The order Qty' is 1~2pc of each part.

The lead time is 7~10 Days.

Project show

2. Machining Team 2

The main work is for some small quantity orders, many types of products with small Qty', use manual equipment, CNC miller, Grinder, wire cutting ,EDM,etc.

The order Qty' is 1~100pc of each part.

The lead time is 15~21 days.

Project Show

We sometimes handle more than 100 items for them at a time.

The used material:

Stainess steel, SS304, SS316, 17-4PH, 440C.

Mild steel, 1018, 1020, C45.

Plastic, POM, ABS, PVC, PE, TEFLON.

Alloy steel, 42CrMo4,16MnCr5.

Aluminium, AL6061-T6, AL7075, AL6063, AL5052.

Brass alloy, Bronze, Copper,etc.

Machining Team 3

The main work is for mass production, some big qualtity orders. Used equipment CNC Lathe,CNC Miller and Automatic Lathe.

The order Qty' is 500pc~4000pc of each part.

The Lead time is 25-30 Days.

Project Show

These three work types, there must be a work type for your mahcining needs. Choosing good quality precision machining service, SYM can help you win more projects.  

Advanced precision machining shop

 Advanced precision machining shop in China

SYM Precision, advanced precision machining shop in south China.

Due to ensure perfect precision and innovative production processes,we brought in new advanced equipment every year. Till now, SYM has 6 sets of 5 Axis CNC milling machine,4 sets of 4 Axis CNC milling machine, 60 sets of 3 Axis CNC milling machine, 50 sets of CNC Lathe, 10 sets of Slow Wire Cutting machine, 5 sets of EDM.

5 Axis CNC milling machine, DMG MORI, DMU95, DMU65, and DMU50.This process not only ensures productive flexibility, but also high cutting performance and maximum precision coupled with high dynamics and excellent accessibility and ergonomics.

5 axis machining used to the machining of parts with more complicated geometric shapes, which requires the machining tool to be able to position and connect in five degrees of freedom.

3 Axis CNC machine, Brother, S500X1, S300X1.

The pursuit of high acceleration, high response, to achieve higher production efficiency, the production efficiency is improved. the z-axis acceleration is greatly increased. In the mass production of machined parts for auto and motorcycle, the production efficiency will be improved to a greater extent.

Star CNC Lathe, SR-20J, SR-38J.

These machines are used for turned parts from 0.2" to 1.5" diameter, can use a large library of tooling for the manufacturing of very complex parts that have turning, drilling, and a variety of secondary operation.Suitable for mass production, multi-variety, high precision parts processing.

Japanese Sodick Slow Wire Cutting equipment adopts the new processing with high speed and high precision (+/-0.002mm), it has the linear electric motor servo system first developed in the world. The shaft drive mechanism of the system features its speed with high response and function of precise positioning.

All kinds of equipment above, under the professional operation, SYM precision machining can help you obtain all kinds of superior quality precision machined parts.Come to contact us today.

The key point for the precision machined manufacturer

The key point for the precision machined manufacturer

With the development of science and technology, the mechanical precision is getting higher and higher now, for the precision machined manufacturer,human resources are the key point. Related to quality management and cost management of a factory.

SYM Precision advocates the management idea of 'people first', and gives full play to the subjective initiative of personnel so that people make the best of their ability. At present, SYM has 370 employees, about 270 production personnel, more than 20 mechanical engineers, process engineers, and quality engineers.

At SYM Precision, there are CNC Turning Team, CNC Milling Team, Slow Wire Cutting Team, EDM Team, Manual Milling Team, Grinding Team, and Manual Turning Team. Each production department according to the level of operation technology, there are apprentice, technician, and master level. 

SYM Precision has a comprehensive training program that provides employees with opportunities to improve in all processes.

Apprentice (2%)

Every year, SYM will recruit some graduates with mechanical majors from a technical school, training three months in the factory, who pass the first assessment will stay, and continue to learn. Assessment every three months, the apprentice who passed the assessment will be an official operator after one year.

Technician (58%)

All technicians at SYM shall have more than three years of machining experience, and shall be trained for one month before taking the job.

Master (40%)

At SYM, there are 40% of the production personnel at the master level, with at least 8 years of precision machining experience and a high level of technical skills. In addition to carrying out their routine work, they will be assigned as needed to impart the operational skills.

Finally, let's talk about the engineers at SYM Precision, whether they are process engineers or quality engineers, who have more than 10 years of experience in precision machining, and are very familiar with the product structure, process points and quality focuses of precision machined parts. With such a professional manufacturing team and our advanced equipment, we are sure to provide you with the most competitive products and services.

how important is staff training

how important is staff training!

SYM Saff Training

With the development of science and technology, the progress of society, 'things' have higher requirements for people, the combination of people and things is often in dynamic contradiction. You are a competent worker today, if you don't keep on learning, you may be out of date next year. People and things are not coordinated,an enterprise wants to be invincible in the competition in modern society, it must pay attention to the staff training.

Staff job skill training is a kind of productivity, enterprise staff through continuous training, skills will have a new promotion, so they have a further specification in the production operation, also further improve the work efficiency. The enterprise production equipment can play out the biggest effect, of each process will be more fluent, so that the production cost savings, eventually form ' training-enhanced skills- enterprise development-retraining' of a virtuous cycle. Staff training is a win-win activity that benefits both enterprises and employees. An enterprise that pays attention to staff training will have a better social impact on improving the quality of the whole society.

Staff training effectiveness, it refers to the benefits obtained by the company and employees from the training. For employees, revenue means to learn new knowledge or skills. For the company, revenue includes the increase of customer satisfaction.

Generally, the training effectiveness are usually shown in the following aspects.

1.Increase of employee knowledge.
The trained employees have the basic knowledge necessary to complete their own work, and the employees can have a good understanding of the basic situation of enterprise operation, such as the enterprise's development prospects, strategic objectives, operation policies, rules, and regulations.

2.Improvement of employees' skills
After training, employees have completed the skills necessary for their own work, such as negotiation skills, operation skills, and interpersonal skills.

3.The change of employees' attitude
Through the training, the company has established a relationship of mutual trust with employees.enhanced their spirit, cultivated their teamwork spirit,and increased their initiative to integrate into the corporate culture.

4.Changes in employee behavior
Employees improve knowledge skills and work attitude positive change, mainly reflected in the employee return to work after the operation, the application of new knowledge and skills to practice, to solve the difficulties and problems encountered in the previous work, the transformation of the original work attitude, enhance the enterprise master the sense of responsibility and team cooperation consciousness, actively contribute to enterprise development.

5.Increase of enterprise benefits
The staff can timely apply the training results to work, improve the quality of product and service, reduce the production cost, finally improve customer satisfaction, and increase the efficiency of the enterprise.

To sum up, the innovation of an enterprise can be realized only when the training is completed and improve through continuous learning.

Choosing the right material for your custom machined part

Choosing the right material for your custom machined part.

Custom Machined Parts

Concerning custom machined part,choosing the right material is one of the most important thing,to save your money.

Here are 4 points for choosing the metal or plastic that is right for your custom machined part.


1. What will your machined part be used for?
The environment where your machined part will be used will have the most significant impact on material selection.If you are using machined part outside or in wet environments,use stainless steel as opposed to carbon steel due to avoid rust.

Design specifications like stress load,tolerance,and types can also impact your choice of material.

2. Do you care about the weight of parts?
Generally, standard aluminum alloys like AL6061 are great, low density options to keep weight down if a metal is required.Plastics like delrin (POM) and ABS can help keep the weight down even more if tradeoffs in strength can be made.


3. Strength and heat resistance
There are many different ways to measure material strength including tensile strength, material hardness, and wear resistance.Selecting the types of strength your design to get the best material for your custom machined part.

Very low or very high temperatures will also restrict you from using certain materials. Environments where the temperature fluctuates are particularly important to consider, since some materials will expand or contract even in environments where the temperature difference is small.

4. Cost
Overall cost of your project will influence your choice of material. the more material your part uses, the more expensive it will be. Special materials and strong materials, such as titanium,carbide steel etc.