A CNC-machined polycarbonate part can pass a dimensional inspection but crack around the holes after assembly.
This is a common problem with clear covers, machine guards, inspection windows, enclosure panels and other CNC-machined polycarbonate parts fixed with screws, bolts or clamps. The part may look fine when it is delivered, but small cracks can appear after it is tightened, vibrated, cleaned or used for a long time.
In most cases, cracks in polycarbonate parts around holes are not just caused by the material not being strong enough. The main problems are usually a combination of hole design, fastener pressure, sharp edges, heat from machining, stress from the manufacturing process, cleaning chemicals and missing information about assembly details when the request for quotes is being prepared.
When you’re working with CNC machined polycarbonate parts that have mounting holes, countersinks or clear surfaces, it’s best to check the drawing, hole layout and installation method before production. This helps to avoid problems like cracks around the holes later on.
Why do polycarbonate parts crack, even though it is resistant to impact?
Polycarbonate is known for its ability to resist impacts, which is why it is used in many places where safety is important. But just because a material can resist impact doesn’t mean it can’t crack under stress.
Cracks often start in areas where there is a lot of pressure on CNC-machined polycarbonate parts. The following are typical weak points: mounting holes, screw holes, countersinks, tapped holes, sharp internal corners and unfinished edges.
When you tighten a screw, the material around the hole is compressed by the fastener load. If the hole clearance is too small, the edge is too sharp, or the part already has some residual stress from the machining, the stress can build up around the fastener.
This is why cracks may not be seen straight away on polycarbonate parts that have been machined. The part can look clear, flat and dimensionally acceptable during inspection, but then develop small cracks around the edge after it has been put together, cleaned, vibrated or the temperature has changed.
The important thing is not whether polycarbonate is strong enough. The important question is whether the hole design, machining process and how it is put together are right for how the part will be used.
Common Symptoms: How Cracks Around Holes Usually Appear
Polycarbonate parts can crack around holes. These cracks often start as small, fine lines. You can find these lines near screws, bolts, countersinks or clamped edges. These cracks can be hard to spot, especially on see-through or slightly tinted PC parts.
Radial Cracks From Screw Holes
A common problem is radial cracking from the edge of a mounting hole. The crack usually starts from the hole where the screw is and spreads outwards. This is because of the pressure from the screw, the stress from the hole or the stress left in the material.
This often happens on clear covers, machine guards, inspection windows and enclosure panels that are fixed with screws or bolts.
Whitening or Crazing Around the Hole
Another warning sign is a white or grey mark around the hole. This can happen when the surface is stressed but not yet fully cracked.
On clear polycarbonate parts, these white stress marks are usually visible before the part breaks. You might see them around drilled holes, countersinks, tapped holes, sharp edges or clamped areas.
Cracks After Tightening Screws
Some CNC machined polycarbonate parts crack only after the screws are tightened.
The part may pass inspection, ship without visible defects and then fail during installation because the hole clearance, countersink depth, screw head contact or tightening force was not suitable for PC.
Cracks After Cleaning or Chemical Exposure
Cracks can also appear after cleaning, disinfecting or exposure to oils, coolants, alcohol-based cleaners or other chemicals.
If you combine chemicals with internal stress from machine tools, you can cause cracking in the area around holes, edges or clamped areas.
Why These Symptoms Should Not Be Ignored
For clear covers, machine guards and enclosure panels, cracks around holes should not be treated as random defects that just affect how things look.
They usually show that the hole design, how it was made, how the fasteners are touching it or what the environment is like needs to be checked before the next production run.
Main Causes of Cracking Around Holes
It is rare for polycarbonate parts to crack around holes for just one reason. Most of the time, the crack starts where design stress, machining stress and assembly pressure overlap.
The following issues are the most common causes of problems with CNC machined polycarbonate parts with screw holes, mounting holes, countersinks or clamped edges.
Hole Clearance Is Too Tight
If the hole is too close to the screw or bolt, the fastener can press directly against the polycarbonate when you put it together.
This means there is not much room for alignment, vibration or thermal expansion. This means that the material around the hole will always be under pressure after it has been installed.
When it comes to PC covers, guards and windows, tight holes might pass a dimensional inspection, but they can still cause long-term stress around the fastener.
Fasteners Are Over-Tightened
One of the most common reasons polycarbonate cracks around screw holes is that the screw is tightened too much.
If the screw head, washer or bolt clamps the PC surface too tightly, the load will be focused around the hole. This can cause cracks, discolouration or unevenness near the fastener.
Polycarbonate should not be treated like metal when it is being put together. A metal part may be able to handle a higher clamping force, but a PC part needs controlled pressure, proper washer contact and enough space to avoid stress cracking.
Countersinks Create Thin Stressed Areas
Countersunk holes can make things look better and stop screws from sticking out, but they also remove some of the material around the hole.
If the countersink is too deep, too sharp or not the right shape for the screw head angle, the remaining wall around the hole becomes thin and is put under a lot of pressure.
This is especially risky on see-through polycarbonate covers, thin panels and parts with visible surfaces. Cracks can start from the countersink edge after you tighten it, even if the part looked OK before you put it together.
Sharp Edges or Burrs Remain Around Holes
Sharp hole edges, machining marks, burrs and small chips can become crack starting points on CNC machined polycarbonate parts.
A small edge defect may not look serious during inspection, but once the part is tightened, cleaned or exposed to vibration, the crack can begin from that stress riser.
For this reason, controlled deburring, light edge breaking and chamfered edges around machined holes are important for PC parts with mounting features.
The goal is not to over-process the part. The goal is to remove sharp stress points without damaging the visible clear surface.
Machining Heat Creates Residual Stress
Polycarbonate can be damaged by heat during CNC machining.
If your tools are dull, there is too much heat around holes and slots, or the cutting is too aggressive, then this can cause problems. This can leave some stress in the material.
The part may still look clear and the same size as the drawing after machining. However, once it is put together, tightened or exposed to cleaning chemicals, the internal stress can cause cracking around holes.
Cleaning Chemicals Attack Stressed PC
Polycarbonate can be affected by some cleaning products, disinfectants, oils, coolants, alcohol-based products and chemical residues.
If the part is already under stress from other forces, it is more dangerous to expose it to chemicals. Things like screw holes, clamped edges and countersinks can cause what is called ‘environmental stress cracking’.
It is important to talk about where the machine will be used before you start. This is especially important for medical devices, food equipment, lab instruments, automation systems and machine guards that need to be cleaned regularly.
Assembly Details Were Not Shared During RFQ
Many problems with cracking start before production, not during it.
If the CNC supplier only gets a CAD file and a material name, they might not know how to install the part. The drawing may show hole size and tolerance, but not screw type, tightening method, washer design, chemical exposure or visible-face requirements.
If you need CNC-machined polycarbonate parts with holes, the RFQ should include how the parts are put together, what type of fasteners you need, how they will be cleaned, and what kind of environment they will be used in. This helps to spot risks of cracking before the parts are machined, not after they have failed when used.
Design Details to Review Before CNC Machining Polycarbonate Parts
You can stop polycarbonate parts cracking around holes by taking care of them before you start machining them. The drawing should show the hole size and tolerance. It should also show how to install, tighten, clean and use the part.
For CNC-machined polycarbonate parts, the way the part is designed can have a big impact on how stable it is after assembly. If there are small design details that cause stress cracks around the holes, the part might not be stable.
Hole Diameter and Fastener Clearance
The hole’s size should be checked against the screw, bolt or pin’s size.
If the fastener is too tight, it might push against the hole wall when you’re putting it together. This creates pressure in one area, which can make it more likely that the area around the screw holes will crack.
When choosing covers for PCs, machine guards and enclosure panels, it’s important to think about how well the holes align, how things expand in heat and how much vibration there is when they’re being used.
Edge Distance Around Mounting Holes
If the holes are placed too close to the edge, there could be a weak area between the hole and the outside profile.
When you tighten the screw, the stress can travel from the hole towards the edge. This can cause cracks, splitting of the edges or the fastener to turn white.
If there is not much space, check the distance from the edge before making the product. Sometimes, moving the hole, increasing the material margin or changing how it is fastened can reduce the build-up of stress.
Countersink Depth and Screw Head Contact
Countersinks need careful review on polycarbonate parts.
A deep countersink removes material around the hole and leaves a thinner stressed section. If the screw head contacts the countersink unevenly, the load may concentrate on a small area instead of spreading across the surface.
For transparent PC parts, countersinks also affect the visible face. Poorly controlled countersinks can create tool marks, whitening or cracks near the screw head after tightening.
Washer, Gasket and Spacer Design
Washers, gaskets and spacers can help distribute clamping force, but only if they are designed correctly.
A washer that is too small may still concentrate stress near the hole. A hard metal washer in direct contact with PC can also mark the surface or increase local pressure.
For machine guards, clear covers and inspection windows, soft gaskets, larger contact areas or controlled spacers may be needed to avoid over-compression around holes.
Tapped Holes, Inserts and Through Holes
Tapped holes in polycarbonate require caution.
Plastic threads are more sensitive to torque, repeated assembly and long-term load than metal threads. If the thread engagement, pilot hole size or tightening method is not right, the tapped hole might start to crack.
For some cnc machined polycarbonate parts, it may be safer to use through holes with bolts, threaded inserts or metal standoffs than to directly tap into PC. The best option depends on how much weight it needs to hold, how thick it is, how many there are and how often they will be put together.
Visible Face and Edge Finish Requirements
Clear polycarbonate parts often have one or more visible sides. These areas should be clearly marked on the drawing or RFQ.
If there are no instructions about which side needs extra protection during machining, deburring, inspection and packing, the supplier might not know.
When making transparent covers and windows, the edge finish around the holes is also important. A clean break can reduce stress risers, while rough burrs or sharp edges may start cracks.
Cleaning and Chemical Exposure
If the part will be cleaned with alcohol, disinfectants, oils, coolants or industrial chemicals, this should be mentioned before quotation.
Chemical exposure can make stress cracking worse, especially around holes, countersinks and clamped edges. A part that performs well in a dry environment may fail faster if it is cleaned frequently while under fastener stress.
This is especially important for medical equipment, food machinery, laboratory instruments, automation covers and safety guards.
Application and Assembly Method
The supplier should know whether the part is used as a machine guard, inspection window, enclosure panel, fixture, light cover or protective shield.
Each application creates different stress conditions. A fixed machine window may need strong impact resistance and stable mounting holes. A removable cover may need better scratch protection and repeated fastening performance.
Need Help Reviewing a Polycarbonate Part With Holes?
If your polycarbonate part includes screw holes, countersinks, tapped holes, clamped edges or visible clear surfaces, send us the CAD file, 2D drawing and assembly details before production.
Baosheng can review the hole layout, fastener contact, visible-face requirements, cleaning exposure and potential stress-cracking risks before quoting your CNC machined polycarbonate parts.
Machining Controls That Help Reduce Stress Cracking
Good design reduces risk, but machining control is just as important. Even when the drawing is reasonable, polycarbonate parts can crack around holes if heat, tool pressure, burrs or residual stress are not controlled during CNC machining.
When it comes to CNC machined polycarbonate parts, the aim is not just to meet the dimensions. The supplier also needs to protect the clear surface, reduce stress concentration and keep holes clean enough for stable assembly.
Use Sharp Tools to Reduce Heat and Drag
Polycarbonate is a strong material that can be cut with sharp tools.
Dull tools can rub instead of cutting cleanly. This makes heat, increases cutting pressure and may cause stress in the material around holes, slots and thin edges.
If you’re having problems with your PC parts, it might be because the cutting conditions are poor. This can cause melting, whitening, rough edges or visible tool marks.
Control Cutting Heat Around Holes
Areas where holes are drilled, countersinks are used and small slots are cut are often places where heat can build up in the polycarbonate around drilled holes, countersinks and small slots.
If the tool is left in one place for too long, heat can build up around the hole wall. This might not cause a crack straight away, but it can leave stress that might show up later when putting it together or cleaning it.
Controlled spindle speed, feed rate, step-down, chip evacuation and cooling strategy help reduce this risk.
Keep Hole Entry and Exit Clean
The quality of the hole is important because cracks often start from small problems.
A rough hole wall, a chipped exit edge or a small burr can cause problems when you tighten the screw. This is especially important for transparent covers, machine guards and inspection windows where holes are both useful and easy to see.
Using the right tools and techniques, such as clean drilling, stable workholding and careful tool selection, can help you make smoother holes with a lower risk of cracking.
Deburr Without Damaging the Visible Face
Deburring is necessary, but if you do it too aggressively, you can end up creating new problems.
For CNC machined polycarbonate parts, the supplier should remove sharp edges and burrs without scratching, gouging or overheating the clear surface.
A slight bend around the mounting holes is often enough. The idea is to reduce stress concentration, not to remove too much material or change how the face looks.
Review Fixturing for Thin or Clear PC Parts
Poor fixturing can bend the material during machining.
If a polycarbonate panel is clamped too tightly, machined while distorted or released after cutting, the final part may contain internal stress even if the dimensions look acceptable.
Thin panels, clear windows and large covers need stable support during CNC machining. This is especially important when holes, slots and edge profiles are close to each other.
Consider Stress Relief for Critical Parts
Some polycarbonate parts need to be checked for stress after they have been machined.
This is particularly important for thin parts, parts with tight measurements, load-bearing holes, parts that are exposed to cleaning chemicals, or transparent components where the parts cannot be made white or crack.
The best way to deal with stress or to make the material softer depends on the material grade, how thick the part is, how precise the dimensions need to be and what the part is used for. The decision should be made before production because the way the product is treated after it is machined can affect its size and how flat it is, as well as how it is delivered.
Inspect More Than Dimensions
A polycarbonate part can meet the drawing size and still carry cracking risk.
Inspection should include hole quality, burr condition, visible-face protection, edge finish, countersink appearance and signs of whitening or heat damage.
For plastic components, dimensional accuracy should be reviewed together with material behavior, machining stress and application conditions. This is why plastic CNC dimensional stability is an important consideration for PC covers, windows, guards and enclosure panels.
Match Machining Strategy With the Application
A simple prototype cover may not need the same process control as a production machine guard or medical equipment window.
Before machining, the supplier should understand whether the part will be fixed permanently, removed often, cleaned frequently, exposed to vibration or used as a safety-related guard.
When the machining strategy matches the real application, CNC machined polycarbonate parts are less likely to crack around holes after assembly.
When the Drawing Should Be Changed Before Quoting
Some problems with polycarbonate cracking cannot be solved by making better machines. If the drawing makes holes look too complicated, the supplier should check the design before giving a quote, not try to fix the issue after production.
This is especially important for CNC-machined polycarbonate parts used as clear covers, machine guards, inspection windows, enclosure panels or safety shields.
Holes Are Too Close to the Edge
If the holes are placed too close to the outside edge, it can make a weak section where the hole is.
When you tighten the screw, the stress may travel through this narrow area and cause cracking, splitting or whitening. This risk increases when the part is thin, transparent or vibrating.
If there’s enough space, try moving the hole further from the edge or increasing the material margin.
Countersinks Are Too Deep
Deep countersinks can make the area around the screw head thin and fragile.
This is a common problem with clear polycarbonate panels where designers want the screw to be flush with the surface. The part may look clean on the drawing, but the remaining material around the hole may not be strong enough to withstand the tightening force.
In some cases, a shallower countersink, a different screw type, a different washer or spacer design may reduce the risk of cracking.
Tapped Holes Are Used in Thin PC Parts
If you have any tapped holes in thin polycarbonate parts, you should check them carefully.
Plastic threads are more sensitive to twisting force and being put together repeatedly than metal threads. If the wall thickness or the way the threads fit together is not enough, the wall can crack when you are tightening it.
For production parts, threaded inserts, through holes, metal standoffs or alternative fastening methods may be more reliable.
Hole Tolerances Are Too Tight for Assembly
A tight hole tolerance may look precise, but it can create problems when the fastener, mating part or fixture has its own tolerance stack-up.
If the screw can’t fit into place, the installer might push the part into position. This puts pressure on the hole wall from the side, which can make it more likely that the wall will crack.
When checking CNC-machined polycarbonate parts, it’s important to consider hole tolerance (how precise the hole size is) along with the overall assembly condition.
Sharp Corners Are Too Close to Mounting Features
Sharp corners, narrow slots and sudden changes in the shape can put too much pressure on a particular area.
If these features are close to a screw hole or clamped edge, cracks may start from the corner and spread toward the mounting area.
You can make the design more stable by adding a proper radius, adjusting the slot shape or moving the hole away from the stress area.
The Visible Face Is Not Marked
Clear polycarbonate parts often fail commercially even when they meet the drawing dimensions.
If the surface isn’t marked, the supplier might not know which parts need extra protection from scratches, clamp marks, burrs or damage from being handled.
For inspection windows, machine guards and transparent covers, the drawing should clearly show what the outside will look like, how the edge should be finished and what is needed for packing.
The Use Environment Is Missing
A drawing can show shapes, but it usually doesn’t explain how they will be used.
If the part will be cleaned with alcohol, disinfectants, oils or industrial chemicals, this should be reviewed before machining. Using chemicals can make it more likely that the wood will crack around holes, countersinks and areas that have been clamped.
The same is true for vibration, outdoor use, heat, repeated assembly or impact exposure.
The Part Needs DFM Review Before Production
If the design includes tight holes, deep countersinks, thin walls, tapped holes, visible clear faces or chemical exposure, the drawing should be checked before we can give you a quote.
A proper DFM review can help identify risks of stress cracking, adjust hole design, improve edge details and confirm whether polycarbonate is the right material for the job.
If you have problems with polycarbonate parts cracking around holes, it’s best to solve them before you start machining.
RFQ Checklist for Polycarbonate Parts With Holes
Sometimes, a CAD file is not enough for CNC machined polycarbonate parts. The supplier also needs to understand how the part will be installed, loaded, cleaned and inspected.
This is especially important when the part includes screw holes, countersinks, tapped holes, slots, clamped edges or visible clear surfaces. These details directly affect the risk of polycarbonate parts cracking around holes after assembly.
3D CAD File
Send a complete 3D CAD file for geometry review.
The CAD model helps the supplier check the thickness of parts, where the holes are, the shape of the slots, the distance between the edges, the depth of the countersink, the geometry of the countersink and any thin-wall areas.
The model can be used to check for problems with the machining process. This includes checking for distortion or stress in the machine guards, clear PC covers and windows.
2D Drawing With Critical Dimensions
A 2D drawing is still important for CNC machined polycarbonate parts.
It should define the most important hole sizes, how much they can be from the centre, how deep the countersink should be, the edge finish, which surfaces can be seen, how flat they need to be and where they should be inspected.
If not all holes are equally important, mark the functional mounting holes clearly. This helps the supplier to focus on inspecting and controlling the processes in the areas where stress cracking is most likely to happen.
Screw, Bolt or Fastener Size
The RFQ should include the size of the screw, bolt, pin or fastener used in assembly.
The size of the fastener affects how well the hole fits, which washer you can use, how the countersink is designed and how much force is needed to tighten it. If you don’t have this information, you can machine the hole to the size shown in the drawing, but there’s still a chance it will put pressure on the fastener when you install it.
If you are getting polycarbonate parts that will be put together more than once, the supplier should also know if the screws will be taken out and put back in a lot.
Washer, Gasket or Spacer Details
If the part needs washers, gaskets, spacers or standoffs, include these details in the RFQ.
These parts affect how the force is spread around the hole. A small hard washer can make pressure build up, while a larger washer or softer gasket can spread out the pressure.
For clear covers and machine guards, the way the water is directed can also affect how clean the surface is, how likely it is to get scratched and how well it will last.
Assembly Method and Tightening Condition
Tell the supplier how the part will be installed.
Important details include whether the part is hand-tightened, torque-controlled, clamped, bolted to metal, mounted to a frame or combined with other plastic or rubber components.
Many cases of polycarbonate parts cracking around holes happen because the machining supplier never received the real assembly condition during quotation.
Visible Face Requirements
Clear polycarbonate parts often have surfaces that are both attractive and practical.
If one side must be kept clear, scratch-free or for inspection, mark it as the visible face on the drawing. This helps the supplier to control the processes of making the product, removing any sharp edges, handling and packing.
When inspecting windows, covers and transparent panels, it is important to check the face of the material that is visible, as well as the quality of the holes and the finish of the edges.
Cleaning and Chemical Exposure
If the part will contact alcohol, disinfectants, coolant, oil, adhesive, threadlocker or other chemicals, mention this before quoting.
Chemical exposure can increase environmental stress cracking, especially around holes, countersinks, threads and clamped edges.
This information is critical for medical equipment, laboratory devices, food machinery, automation systems and machine safety guards.
Application Environment
Explain what the part is used for in the real world.
The supplier should know if the polycarbonate part will be exposed to vibration, impact, temperature changes, outdoor conditions, repeated removal, cleaning cycles or continuous clamping force.
A PC part used as a simple prototype cover does not need to be reviewed in the same way as a production machine guard, inspection window or safety-related enclosure panel.
Quantity and Inspection Requirement
Please share the number of prototypes, how many will be produced, and what the inspection requirements are.
For low-volume prototypes, the focus may be on feedback about how things fit together (DFM), testing to make sure they fit well, and protecting the surface so it can be seen. When making lots of something, it’s also important to think about how well the process can be done again, how it’s packed, if the holes are all the same, and how well it all stays put.
If the part has important mounting holes, ask for them to be checked carefully before shipping.
Notes
Send your CAD file, 2D drawing, hole layout, fastener details and assembly method to Baosheng before production.
Our team can review polycarbonate stress-cracking risks, visible-face requirements, hole quality, edge finish and machining details before quoting your CNC machined polycarbonate parts.
This helps reduce the chance of polycarbonate parts cracking around holes after assembly, cleaning or long-term use.
FAQ: Polycarbonate Parts Cracking Around Holes
Why Do Polycarbonate Parts Crack Around Screw Holes?
If you put too much pressure on polycarbonate parts, they will crack around the screw holes.
The most common causes include tight hole clearance, fasteners that are too tight, sharp hole edges, deep countersinks, machining heat, residual stress and chemical exposure.
In CNC-machined polycarbonate parts, the crack usually starts from a stress concentration point. This could be the edge of a screw hole, a countersunk hole, a tapped hole, a burr, or a clamped area.
Can CNC Machining Cause Stress Cracks in Polycarbonate?
Yes. CNC machining can cause stress cracking if the cutting heat, tool pressure, chip removal or edge quality is not controlled.
If the tools are dull, the cutting is aggressive, the fixturing is poor and the hole edges are rough, this can cause stress in the part. The part may pass dimensional inspection, but cracks can appear later after assembly, cleaning or vibration.
This is why it’s important to check the machining strategy, hole quality and visible-face protection before production.
Should Screw Holes in Polycarbonate Be Oversized?
In many cases, polycarbonate screw holes need to have enough space around them for alignment, thermal expansion and controlled assembly.
If the hole is too tight, the screw or bolt might press against the hole wall. This puts pressure on the area around the hole, which makes it more likely that the hole will crack.
However, the correct clearance depends on the screw size, the thickness of the part, how close the parts are together, the load, the washer design and the environment. The review should be based on the actual drawing and assembly method.
Does Annealing Help CNC Machined Polycarbonate Parts?
Annealing or stress-relief treatment may help some CNC machined polycarbonate parts reduce internal stress.
It is more relevant for thin-wall parts, transparent covers, tight-tolerance components, load-bearing holes and parts exposed to cleaning chemicals.
However, annealing is not a universal fix. It can affect size, flatness and delivery planning, so it should be discussed before production instead of added after cracking has already occurred.
Can Alcohol or Disinfectants Crack Polycarbonate?
Some cleaners, disinfectants, alcohol-based products, oils, coolants, adhesives or chemical residues can make polycarbonate more likely to crack in the environment.
The risk is higher when the part is already under mechanical stress. Chemical exposure can cause cracking in screw holes, countersinks, tapped holes and clamped edges.
If the part will be used in medical equipment, food machinery, laboratory devices or automation systems that are cleaned often, chemical exposure should be included in the RFQ.
Is Polycarbonate Better Than Acrylic for Parts With Holes?
Polycarbonate is usually tougher and more impact-resistant than acrylic, which makes it a better choice for many machine guards, protective covers and inspection windows.
However, both materials can crack if hole design, cutting heat, edge finishing and assembly pressure are not controlled.
If your clear part may use acrylic instead of PC, review the machining risks carefully. You can also read our guide on machining acrylic without cracking to compare common cracking risks in transparent plastics.
How Can You Prevent Polycarbonate Parts From Cracking Around Holes?
The best way to stop this is to check the drawing and assembly condition before machining.
Check the hole clearance, edge distance, countersink depth, fastener type, washer contact, tightening method, visible-face requirements and chemical exposure.
When it comes to CNC machined polycarbonate parts, cracking prevention is about more than just the machining process. It requires the design, material, machining process and installation method to work together.
Conclusion: Prevent Cracking Before the Parts Are Machined
If polycarbonate parts crack around holes, it is usually not just a random defect. It is often the result of a combination of factors, including stress from holes, pressure from fasteners, heat from machining, sharp edges, residual stress, or exposure to chemicals after assembly.
When making CNC machined polycarbonate parts, it is important to check the drawing, hole layout, countersink design, fastener contact, visible face and use environment before production starts.
If your PC part has screw holes, tapped holes, countersinks, clamped edges or transparent surfaces, do not wait until there are cracks after installation.
Send your CAD file, 2D drawing, hole layout and assembly details to Baosheng. Our team can check the risks of the machining process, where the material might crack, and what the finished product will look like.
