Aluminum End Caps FAQ

Nelsons CNC End Caps are made from aluminium. It is important to know exactly what size material you are capping as each end cap has been designed to fit specific aluminium extrusions. Measure the external dimension of your extrusion, wall thickness and note if your extrusion has a square or radius edge. To ensure your aluminium caps are a perfect fit we recommend measuring your extrusion with a vernier.

Our end caps are named according to size: Example 50x50x3 R6

A = 50mm (Outside dimension) 
B = 50mm (Outside dimension) 
C = 3mm (Wall Thickness) 
R = 6mm (Radius Edge)

More detail is covered in how to measure aluminum tube for end caps and square edge vs radius edge aluminum end caps.

Yes. We pay all the duty tax on every order.
All our end caps are manufured and shipped from in Australia. As the shipper we pay all duties, tariffs , taxes and freight costs so there is no additional cost or liability on your end.

U.S Customs does require the customers Tax ID on all shipments of $800 or over. This is a standard step for importing goods into the USA. Providing your Tax ID at checkout is safe and secure and is used solely for customs clearance and doesn't pose any financial or personal risk to you. It's similar to providing a business tax id for routine transitions.

We just need your Tax ID to comply with U.S import regulations and get your order to you hassle-free.

All our aluminium end caps are 0.25 inches thick.

For more detailed photos of individual products please refer to our end caps in our online shop.

Please check our extensive range of sizes in our online shop before contacting us for a custom sized end cap. We create custom end caps from die drawings or diagrams of your extrusion you are wishing to cap. Visit our Custom Size page for more info

No, our end caps are made to fit into the end of aluminum tubing and can not be fitted into wood.

If you are not satisfied with your product, contact us to organise a exchange or refund within 30 days of purchase. Do not weld or glue these end caps. They should be a tight fit without movement once installed. If the item is too small or big please contact us so we can organise the correct sizing for you.

Stocked items will be shipped the next day via FedEx International Priority. You will receive a email notification when your order has been dispatched.

We ship Worldwide from Australia and use Fedex International Priority. In stock items usually take 5-8 business days depending on your location.

Our aluminum end caps are precision-machined in Australia using premium 6060 T5 aluminum, with USA order support through our Delaware office.

We have an office in Delaware but our manufacturing plant is in Australia, we are currently building a factory in Florida that should be open soon.

In stock orders are usually dispatched within 12 business hours of being placed. For order updates or lead time enquiries, email our team at and we will get back to you shortly.

Most orders arrive within 3 to 7 business days, depending on destination and customs clearance. Many customers also comment in our reviews on how quickly their orders arrive considering they are shipping from Australia.

Shipping to the USA starts at $40 using FedEx International Priority, depending on the size of your order and delivery location. Orders over $50 qualify for free shipping, with exact shipping shown at checkout before payment.

Yes but we pay all import duties, tariffs and customs charges so there are no hidden costs charged to you on delivery.

Not at this stage but we would love your local Aluminum supplier to be able to carry our products so that you could buy your tubing and the end caps to suit all in one place.

Yes we can manufacture custom size end caps. To quote correctly, we need your outside tube size, exact wall thickness, and whether the tube has radius corners or square corners. Submit these details through our Custom End Cap form on our website and we’ll review it and get back to you.

Yes we make end caps for schedule pipe. Send your measurements through on our website through on our Custom End Cap form.

Yes we can send you end cap samples. Send your size to our email address.

No end caps won’t fall out in extreme weather. Aluminum expands and contracts at the same rate together.

Hole plugs are designed to plug unwanted holes and end caps are designed to cap off the end of a hollow tube or pipe.

Yes. Only powder coat the top and the sides of end caps.

Yes they do fit, but there is a corrosion risk. Our recommendation is to always use our aluminum caps with aluminum tubes to eliminate any issues.

Our knock-in aluminum end caps are an interference type fit and can be installed with 3 to 4 firm hits with a rubber mallet also known as a soft hammer.

Small variations in aluminium tubing are common, even when the outside size is the same. To suit this, we can machine end caps with small raised points called pips on the interference-fit section. These tiny grip points help the cap hold securely inside tubing where internal sizes vary slightly due to wall thickness differences or supplier tolerances. Pips are not standard and need to be requested when ordering. For best fit, always measure your tube wall thickness accurately with digital calipers, as even small differences affect the internal size

They are better quality, install quickly without welding, stay in place, won’t fall out, last much longer, and come colour-ready so you can match your job perfectly.

Yes aluminum gives a tighter fit, better durability, improved weather resistance, and a cleaner finish, especially for fencing, rails, facades, and architectural work.

Wall thickness is critical because each end cap is machined to suit a specific internal size. Measure your tube wall with digital calipers and match that measurement to the product listing or contact our team for help choosing your perfect fit.

No lubricant is normally needed. A correctly sized cap should install cleanly dry.

Yes — our end caps are designed so approximately half the thickness inserts into the tube and the outer face finishes clean and flush on the outside.

Yes — we regularly supply large production quantities with fast turnaround because all machining is done in-house.

Contact us directly for our best price on bulk orders via email or request a call back.

All end caps are made and shipped from Australia, with US ordering support from our Delaware and Florida offices.

Yes — FedEx International Priority is fully trackable and most US orders arrive quickly within 3-7 days.

We use premium quality 6060 T5 aluminum for all our end caps.

Place the end cap on the end of the tube and tap it in with a rubber mallet until it is fully fitted. Once installed correctly, it will sit tight with no movement.

We stock a wide range of aluminium end caps to suit common square, rectangular, and round aluminium tube sizes. Sizes vary depending on wall thickness and internal corner shape, so it’s important to match your tube correctly. We also make custom sizes for non-standard extrusions.

Choose the end cap to match your exact tube size and wall thickness. Each end cap is made for a specific fit, so even small wall thickness differences matter. Measure your tube carefully, then select the matching size on our website. If you can’t find your size, contact us as we can make custom sizes.

Yes—for custom extrusions or branded caps (e.g., engraved logo on flange). Minimum order usually 100pcs. You can send your drawing through to us for a quote.

They are precision CNC-machined from premium 6060 T5 mill-finished aluminum bar stock for durability and a professional finish.

All end caps are 0.25 inches thick.

We have end caps to fit for square, round, and rectangular aluminum tubing..

A rubber mallet or a soft hammer is usually sufficient. Avoid metal hammers to prevent damage to the metal.

Yes, when installed correctly on properly prepared tubing ends with the right size match, it provides a tight, movement-free fit for static applications.

All our end caps are designed for static non-vibrational use. Vibration or extreme movement may affect long-term fit.

Yes, all our end caps are supplied in mill finish so they can be powder coated, anodized, or given a wood-grain sublimation finish before or after installation.

Measure the external dimensions (width/height), wall thickness, and note if edges are square or radiused. Use a digital calipers for accuracy and exact measurements are required to ensure a tight fit. See also how to measure aluminum tube for end caps.

Measure the outer dimensions and the wall thickness of your tubing — our press-fit caps insert into the open end of the tube.

We offer custom-sized end caps. Send us your tubing diagram, die drawing, or precise measurements for a quote via our Custom Size form located on our website.

Visit our Custom Size End Caps page on our website, provide exact measurements or a spec drawing and our team will be in contact with you shortly with a quote.

No our end caps are not suitable for wood posts— they are specifically designed to press-fit into hollow aluminum tubing and extrusions only.

Yes — aluminum is corrosion-resistant, especially when finished powder coating or anodizing making them ideal for railings, fences, and facades.

End caps are perfect for aluminum railings, fences, balustrades, handrails, posts, screens, facades and other architectural and structural metalwork.

Yes — they are popular for capping open ends of aluminum fence posts to give a clean, professional look.

Yes we ship worldwide.

We offer free shipping on orders over $50.

In-stock items typically arrive in 5-7 business days via FedEx International Priority.

30-day returns for exchange or refund if unsatisfied. Contact us directly before returning.

Contact us immediately — we’ll help confirm sizing or arrange an exchange for the correct size.

Custom items may have limited return options — check with us direct before ordering.

Yes we offer bulk discounts, trade pricing and distributor discounts for big orders.

No, our end caps are supplied in mill finish aluminium, ready for powder coating, painting, anodising, or other finishing to suit your job.

Email info@nelsonscnc.com or request a call back and one of our product specialists will get in contact with you shortly.

Yes, you can check our install videos on Instagram @nelsonscnc to see installation video.

You can find us on Instagram at @nelsonscnc.

They are designed for permanent fit but can sometimes be pried out carefully if needed.

No — they are cosmetic closure caps, not structural supports.

Varies — contact us with specs for current production times. Once we have the drawings or measurements time in production is usually only 2-3 days. We make everything in house so turnaround is quick.

We offer secure options via Shopify (credit cards, etc.) — details are found at checkout.

Yes — we use standard e-commerce security; see our Privacy Policy on our website for more information.

Yes — check our Hole Plugs for covering unwanted holes.

All our end caps are manufactured in Australia however we have a US entity Nelsons CNC USA Corp for easier ordering.

Yes — you’ll receive a FedEx tracking email once your order is dispatched.

Contact us with your order number — we’ll check with FedEx.

It is a tight interference fit, the end caps are designed for no movement when they are correctly sized.

No, they are made to be a tight inference fit - use a rubber mallet to install end caps.

Yes — match the radius to your extrusion’s corner radius for flush fit.

Yes — we offer bulk pricing on larger quantities, with automatic price breaks as volumes increase: 50 units receive 15% off, 100 units receive 20% off, 500 units receive 25% off, and 1000 units receive 30% off.

No minimum but if you spend $50 or more you’ll get free shipping.

Aluminum performs well, especially anodized but not for submersion.

Match your external dimensions and wall thickness exactly to our product specs.

All end caps are supplied in mill finish standard. Contact us via our website for custom finishes available via powder coat/wood grain finish.

YOu can contact us via our website within 30 days for exchange assistance.

Yes we do. Ensure you select currency and country at checkout.

FedEx provides standard coverage; contact us via our website for options.

If not yet shipped, yes — email us quickly as most orders are dispatched within 12 hours.

Welded caps are generally the most permanent option because they become part of the section itself, but our aluminum end caps are designed to provide a very durable finished result without the time and labour involved in welding. Their true interference fit locks tightly into the internal walls of the aluminum tube, so they stay firmly in place under normal use, while avoiding heat distortion, weld cleanup, and extra finishing. For most fencing, balustrade, rails, and architectural applications, they provide a strong, clean, long-lasting alternative that can also be powder coated, anodised, or timber-look finished to suit the project. Read more in aluminum vs plastic tube end caps.

Yes — check our Instagram or website gallery for real-world examples.

Absolutely — our end caps are commonly used for capping handrail tube ends.

This may affect fit. We suggest to send the profile details, including a photo to our email for custom advice.

info@nelsonscnc.com

Listed sizes are precise; we cater to both systems.

We stock over 200 standard end cap sizes that are available to purchase online.

Minimal as they are primarily used for finishing and protecting the ends of the tube.

We do not recommend gluing end caps as they are designed to be a tight fit without adhesive.

The customer is responsible for return shipping costs unless there has been an error on our part. U.S. customers can return goods directly to our Florida office, with typical domestic return shipping starting at $10 for small parcels.

Contact us first with your order details so we can confirm the return is approved and provide the correct return address. Once approved, securely pack the goods and send them using a tracked shipping service to our Florida office.

Please contact us before returning any order so we can confirm the correct return address and approve the return first.

Contact us first with your order details and the size issue so we can confirm the best return option. Once approved, securely pack the unused end caps and send them using a tracked service to the return address provided.

Format shows dimensions + wall + edge type (e.g., square or R for radius).

Yes — popular for clean, safe finishes on balustrade posts.

Lightly deburr extrusion or send a photo via email to confirm sizing with us.

Radius for rounded corners; square for sharp to match your tubing.

Mill finish aluminum is food-safe in many cases; consult for specific needs.

Yes you can, contact us via email for distributor pricing and our terms.

All our end caps are manufactured in Australia and we have a US Office in Delaware and Flordia.

Please contact our team direct via email with our size and quantity required for our best price.

Yes please email your sizing questions and our team will reply shortly. You can also request a call back.

Yes they seal and prevent dents/debris entry.

Send a photo to us via email so we can work towards a quick resolution.

No. All standard size end caps are the same price as our current range. Custom pricing generally applies when the order involves a non-standard shape, powder coating or special cutouts

Yes — our end caps are commonly used on architectural facades to create a clean, finished end while sealing the open section for a neat professional appearance.

No — buy as few as one but if you spend $50 or more you’ll get free shipping.

End caps can be purchased directly through our website by selecting your size and quantity.

Contact us immediately via email to see if the order has been shipped. Alternatively you can request a call back from our team.

Yes the internal fit is unaffected by external anodizing.

No you don’t need to weld our end caps. They are a tight interference fit.

No don’t glue our end caps, they are made to be a tight interference fit without glue.

You can return your goods directly to our Florida office. Contact our team via email with your order number first.

End caps can be purchased directly through our website by selecting your size and quantity, or by contacting us if you need help choosing the correct fit or require a custom size.

Our end caps are precision CNC machined in-house for a true interference fit, giving a tighter and more accurate finish than generic multi-fit options. They are designed for quick knock-in installation without welding, screws, or glue, and are supplied in mill finish so they are color-ready for powder coating, anodizing, or other finishing to suit the job. ⚙️✨

You can view customer reviews on our website homepage, on our Amazon listings, through Google, and across our social media pages. Many reviews highlight the precision fit, product quality, and fast shipping, even for orders sent from Australia.

You can find our products on Amazon by searching Nelsons CNC aluminum end caps to view our current listings.

You can buy our end caps directly from our website or through our Amazon listings, depending on the size and quantity you need.

Our caps rely on a precise interference fit. Even 0.003” difference in the wall can prevent installation or cause looseness. We recommend you measure your tube with a vernier caliper for accuracy.

Use digital/vernier calipers at multiple points on the tube or extrusion end (avoid rounded/burred areas). Average readings and match exactly to our listed C dimension.

Slight manufacturing variation in tube or extrusion wall thickness is common, and if the size is within about 0.005", the end cap will often still fit tightly. If the tolerance is outside that range, we can custom machine end caps to suit your exact internal size. For best results, test with a sample end cap or send us your measurements and photos via our Custom End Cap page on our website.

Not ideally, gaps or poor aesthetics may occur. Always match edge style (square or radius) to your profile.

Yes—deburr/file edges clean before measuring/installing to ensure accurate fit.

It should be snug and hand-push resistant. If too loose by hand it’s likely the wrong size.

Likely wall too thick or burrs present. Deburr extrusion, lightly chamfer inside edges, or confirm size (common with 0.005”+ mismatch).

If the cap installs but feels loose, the tube wall may be thinner than expected or the tubing may be slightly oversized internally. Measure the tube wall thickness and internal size to check it matches the specification ordered. If the size is incorrect, contact us so we can help arrange the correct fit — avoid forcing, gluing, or modifying the cap, as the correct interference fit is the best solution.

Aluminum naturally expands and contracts with temperature changes, but because both the end cap and the aluminum tube are made from aluminum, they expand and contract together at a very similar rate. When the cap is installed with the correct interference fit, it remains locked in place under normal climate conditions without the need for glue or adhesives. In extreme temperature conditions, fit should still remain stable provided the correct size has been selected for the tube.

Yes they can. Our end caps are designed to suit static use.

Square-cut ends essential for flush fit. Re-cut square if angled.

Both premium alloys; 6063 offers better extrudability/finish, 6060 good strength—both corrosion-resistant for outdoor use.

Develops natural patina; powder coat/anodize for enhanced protection/longevity.

Anodized or powder-coated versions perform well; mill finish may pit faster, we recommend finishing the end caps for protection.

Aluminum is durable; finishing adds protection. Avoid abrasive install tools.

International Priority is reliable (5–7 days typical); you can track via email link and contact us if issues.

FedEx International Priority is fastest shipping available. For smaller quantities you can purchase our end caps from Amaon which overs overnight shipping.

If not dispatched, yes—email us quickly.

Die drawing, DXF. diagram, photos with measurements, or sample tubing details.

It all depends on complexity and quantity. We machine all end caps in-house so once we receive all required measurements turnaround in production is 2-3 days plus shipping time.

Yes—if dimensions match; aluminum suits outdoor exposure.

nelsonscnc.com

You can contact our team direct on 484-398-9007 and request a call back.

So the end caps are actually a ¼” in total thickness. The part that gets knocked into the inside of the tubing is ⅛” thick and the flange that sticks out is ⅛” thick, making your post ⅛” longer once you’ve installed the end cap.