Caps & Plugs Manufacturer, Supplier.
  +60 3 6207 3333
Click here to register!

Request Free Catalogue
Your cart is empty
Sample Request

No Sample request in cart



A key component in countless engineering applications, caps and plugs offer protection during the manufacturing process. Aside from this, they help during transportation and storage and altogether ensure a project runs smoothly and safely – but it’s often vital they offer shock absorption qualities.


Causing downtime and waste, shock can result in a host of inefficiencies on any given project. It’s the reason shock absorption is so important, as it boosts the lifespan of the application, as well as ensures it operates more safely.


When undertaking any new project, it’s important you take into account the end use of caps and plugs, before deciding on the right ones. Consider everything from the environment in which the components will be used, to their intended application. As caps offer protection or masking qualities, you need to understand the variables of your application; if you’re focusing on its protection ability, consider which part of the component requires protection and therefore how the plug or cap will need to perform.


If, however, your cap or plug is instrumental when it comes to shielding against entry or escape of liquids, consider the surface area which requires masking and the challenges you may face in doing so.


Shock absorption is key to eliminate any adverse effects or damage to your application – or to an individual, with some of the most important characteristics of a material which offers shock absorption properties, including the following:

  • The capacity to reduce oscillations across a range of frequencies
  • The ability to perform well under a range of temperatures – or changing temperatures


Why should you protect against shock absorption?

The fact is, applications may be exposed to shock and vibration during transport and handling – and engineers often seek to reduce such damage caused by the shock.

Shock could occur from applications falling from a height by being dropped, or any unnecessary jostling during transportation.

It’s why shock absorption is a key consideration when it comes to caps and plugs used extensively in engineering: namely, can your cap or plug withstand a high-impact environment. Can it, therefore, provide shock absorption? By assessing such variables prior to commencing your project, you may save time and money. As GWP Group reports: “…equipment, parts or components damaged in transit can lead to a significant amount of wasted time.”

“Similarly, if you are part of another manufacturer’s supply chain, components that you supply to them that are damaged can slow their own production lines (or even halt it in extreme cases), affecting not only their operational productivity but also the relationship between your businesses.”

Taking the time to understand your production process means you can ascertain how your caps and plugs can be applied – which varies from manual to tool-based – which will ultimately ensure your project runs more smoothly.

Depending on the goods you are transporting, the type and quality of protection required may differ from product to product. Materials which offer more durability, for instance, will need less protection, while engineers should also consider how components will be shipped and handled, as well as how they’re protected before being packed.


Caps and plugs: how they help the manufacturing process

Pushing or threading over the outside of a part, caps are important during the manufacturing process. Meanwhile, plugs push or thread inside the part and both components are critical for engineers.

They help in the following ways:

  • Protect open holes
  • Keep out moisture
  • Protect exposed threads
  • Protect during finishing processes
  • Protect against damage, such as dents, bumps and scratches


Start by identifying the right material

By selecting the right material for your environment, you’ll find it becomes much easier to choose the right cap or plug. If you require shock absorption properties, flexicaps made of PVC should be your go-to component, as they’re flexible (as the name would suggest) and durable. Stretching onto larger dimensions for a snug fit, they provide shock absorption and ensure your job runs more smoothly.

Manufactured from plastics, such as low-density polyethylene (LDPE), high-density polyethylene (HDPE), nylon and polyolefin, caps and plugs offer a range of characteristics, ranging from flexibility, good chemical resistance and the ability to withstand high temperatures.

Caps and plugs can also be made from nitrile, vinyl, PVC and even paper, with applications as varied as vehicles, equipment manufacturing, metal fabrication and pipe protection.


Caps and plugs that can take the shock

As components are particularly vulnerable to damage during transportation and storage, it’s vital caps and plugs with shock absorption properties are used to protect them. Below are a handful of plugs and caps to consider.

Tapered caps and plugs (both standard and heavy-duty) – Plugging multiple internal diameters (IDs) or capping outside diameters (ODs), these tapered caps and plugs come with rugged wall seals, providing you choose the heavy-duty version. When optimum protection is needed, this type of cap and plug will serve you well. Made of LDPE, it has high impact resistance, while still offering flexibility.

Full-face all-around flange covers – With the full-face all-around flange cover, you can prevent, dust, dirt and moisture ingress to protect bores and bolt holes. Look for flange covers made of polyethylene (the parent of LDPE), which has excellent shock absorption and vibration dampening properties.

Raised face studded flange protectors – There’s no need for fasteners with the raised face studded flange protector; the kind made from low-density polyethylene will yield the best results. Valuable pipes and flanges can be protected from moisture and debris with these protectors, minimising product impairment during shipping and storage.

Flexicaps – Offering high-impact and shock resistance, PVC flexicaps can be used for most masking applications and are easy to fit, as well as being versatile.


Other reasons to use caps and plugs

Caps and plugs, providing you select the right one for its intended end use, allow you to save time, thanks to their swift and simple removal. Offering precision protection for threads and quick and reliable application, caps and plugs are key for any engineering job.

Sealing the end of a pipe to protect components against dirt, plastic caps come in a host of sizes and profiles. Ribs, finer grip and a variety of materials are available, and they can be used on threaded and non-threaded pipe ends.

Masking a variety of holes with ease, the right caps and plugs are hard-wearing and provide high-temperature tolerance, too. One-size solutions are available, too, which allows for reliable transportation of vital components, while high-impact, shock-resistant plugs and caps mean you can rest assured your project can be undertaken safely.

You can explore custom solutions as well. Remember: the first step in any successful project is identifying your components’ end use and making sure you’ve used the right caps or plugs to protect them.

Selecting the right spacer for your project can be a challenge, so it’s essential to consider a number of factors before you commit to purchasing. Luckily, Essentra has over 50 years’ experience in developing and manufacturing spacers for PCBs.


Here are Essentra’s 3 Top Tips, helping you towards selecting the perfect spacer for your project.




Understanding the application or environment that your spacer will be operating in is essential when choosing the right solution. Before making your decision, here are some key questions:


What type of PCB substrate are you working with?

What kind of material is the mounting panel?

Are there any space limitations?

What other circuitry is present on the PCB?


Of the questions above, the two most important areas are the PCB substrate and space limitations. 



Knowing the material your application demands is vital when choosing the right spacer. Material can directly influence tensile strength, conductivity, prevention of short-circuits, temperature stability and conformance to legislation such as RoHS, Reach and UL94. So what’s the right spacer material for you?


Plastic spacers – we recommend Nylon, PVC, Acetal and PEEK®. 

Metal spacers – we recommend Steel, Brass, Stainless Steel and Aluminum. 



*PEEK® is a premium grade plastic and may not achieve cost efficiencies comparable to other plastic types.



Finally, the mounting type you choose is determined by your application (mentioned in tip 1) and spacer material (mentioned in tip 2). Here are some examples of mounting types we recommend:

1.Threaded – Held in position with the use of a nut to give a very secure fixing that can be released and re-tightened

2.Snap Lock – Pushes into a panel or chassis hole, giving a secure but easily releasable fix

3.Snap Fit– Quickly pushes into a panel or chassis hole, giving a strong but efficient mounting that saves you time when undergoing mass installation

Press Fit / Blind Hole Spacer -  Fins hold securely to a range of binding holes with a pointed style that drives easily into applications with space restrictions

5.Adhesive Base – Adhesive tape eliminates the need for a mounting hole, providing time and space efficiencies


For more advice about Circuit Board Hardware, please call us on +60 36207 3333 or email



Hose protection features
Industrial strength and abrasion resistance
Flexible and easy to fit
Extruded tube provides natural memory
Good resistance to UV ray
Light weight whilst maintaining industrial strength and quality
FRAS (Flame Retardant Anti-Static spiral guard) is also available
How to calculate quantity of spiral guard required

Example: Length 17.5 m/Outside Diameter 40 mm/Inside Diameter 35 mm
40 ÷ 35 = 1.143
1.143 x 17.5 = 20 meters

Need more information? Call us at +60 3 6207 3333

* Price per roll with minimum 10 rolls in a single order.

Try before you buy

Specialist Hydraulic Caps and Plugs
Order free sample
Hose Protection

Order free sample
Hose Clamps

Order free sample

Order free sample


The project’s secured and you’ve mapped out a rough plan of action – but what about materials? Fasteners are likely to feature high on your list of priorities, but which kind is best?


Manufactured in a wide variety of materials – from titanium to plastic and steel – fasteners can also be whittled down even further: by different grades. Describing a particular alloy mixture or hardening process, for instance, these grades help you make an informed decision when it comes to choosing the fastener for you.


Available with a range of coatings or plating, used to enhance the component’s resistance to corrosion, different fasteners offer a different aesthetic, too.


What should you look for in a fastener? Here are just a few things to consider:

  • Strength
  • Brittleness
  • Corrosion Resistance
  • Galvanic Corrosion Properties
  • Cost

In the instance where you’re replacing a fastener, it’s a good idea to match the component you’re replacing. Some equipment is designed so that its bolts will fail prior to more expensive or critical items being damaged, which is why it’s important not to simply replace a bolt with a stronger one. This is due to the fact that it could be more brittle and will have therefore have more chance of failing.


You must also consider the environment of your project. Salt water can lead to galvanic corrosion, for example, which will mean your fastener didn’t quite turn out to be quite as cost-effective as you first thought and hoped.


Let’s take a look at some of the key materials used in fasteners:


Stainless Steel

An alloy of low carbon steel and chromium, stainless steel offers enhanced corrosion properties, as well as a good price. Its anti-corrosive properties are integral to the material, and the component won’t lose this resistance if, for example, it is scratched during the installation process.


Be aware, though, that stainless steel isn’t stronger than standard steel; this is a common misconception. Instead, due to its low carbon content, stainless steel alloys often can’t be hardened during heat treatment. When comparing stainless steel to standard steel, you’ll find that the stainless alloys used in bolts are that bit stronger than grade 2 – an un-hardened grade. That said, they are quite a lot weaker than hardened, steel fasteners, and unless care is taken during installation and thereafter, fasteners made from stainless steel can seize up.

The most common stainless designation for hardware is 18-8 stainless, which refers to stainless steel containing around 18% chromium and 8% nickel. Meanwhile, stainless 316 is a highly corrosion-resistant grade of stainless steel, and though more expensive than 18-8, it can be used to great effect in chlorine and salt water environments.

Harder than 18-8 stainless steel yet not quite as resistant to corrosion, meanwhile, is stainless 410.



The most common fastener material, steel can come plain, or with surface treatments, including chrome or zinc plating, or galvanization. More often than not, steel fasteners come in four grades – grade 2, grade 5, grade 8, and alloy steel, with the latter plated, in most cases at least, with blue-ish or yellow zinc coating.


How do you determine bolt grade in steel fasteners?

Look for the manufacturer’s stamp or mark, as well as a marking on the head. This tends to show what grade of bolt you’re dealing with, with some of the most common being three radial lines, six radial lines, or even no markings at all.


Alloy Steel

Manufactured from a high strength steel alloy, alloy steel bolts typically come un-plated. This means that, in terms of appearance, they have a black finish – and while they’re extremely strong, they can be brittle.



Similar to stainless steel, aluminium’s corrosion resistance is integral to the material. This means that any nicks or scratches are unlikely to affect its corrosion resistance. Light and soft, fasteners made from this material are done so from a variety of alloys, with elements including silicon, iron, copper, zinc, or manganese. Silicon is used to increase melting point and strength for a product you can rely on.



Polished for appearance, these fasteners are chrome-plated. This allows for a similar resistance to corrosion as zing plating.

What about downsides, though? Chrome can be expensive, but it’ll certainly give that project – whether it’s a car, boat, or motorbike – a professional finish.


Silicon Bronze

Finally, silicon bronze is another key material for fasteners – but how does it fare?

More often than not, silicon is known simply as bronze. An alloy manufactured mostly from tin and copper with a small addition of silicon, this component can be used to great effect in marine environments, such as during the construction of a wooden boat. This is due to its excellent corrosion-resistance and high strength. Drawbacks include its high cost, but for the right project, silicon bronze will prove itself as the right variety of fastener for you.


For more advice please call us on  +66 36207 3333 or email

The role of caps and plugs


Whether we’re talking about a fuel line, pipes, sheet metal, a hydraulic assemblies or other important parts, caps and plugs play a vital role in protection. 

Often the two words are used interchangeably. Caps, however, push or thread over the outside of a part, while plugs push or thread inside the part. Whether cap or plug, here’s what they do:

Protect open holes

Caps and plugs prevent dirt, dust and any other debris from contaminating the opening during manufacturing, storage and transportation. Some caps and plugs can be used multiple times and many are versatile enough for different stages in processes. 


Keep out moisture

Moisture or liquids can ruin electrical systems and cause rust. O-rings provide an airtight seal in these instances to ensure you’re offering a quality product. 


Protect exposed threads

Damaged threads can bring manufacturing assemblies to a halt and stop you from getting the tightening torque you’re after. Tear-off caps not only protect your threads, but they’re quick and easy to remove.


Protect during finishing processes

When it comes to masking holes, you have a range of choices in caps and plugs for low to high-temperature processes.


Protect against damage

Scratches. Bumps. Dents. Caps and plugs are your insurance that your critical components will survive whatever happens without a blemish.


When to use caps and plugs

Generally – and depending on your application – you need the protection of caps and plugs during manufacturing, masking, storage and transportation, and sometimes, end uses.


  Quick Links  
Caps & Plugs Plastic Caps, Plastic Plugs PVC Caps, PVC Plugs Vinyl Caps, Vinyl Plugs Silicone Caps, Silicone Plugs
Please Wait