FREQUENTLY ASKED QUESTIONS (FAQ)

To do so, simply follow these steps:

• Click on the shopping basket icon next to the relevant products to add the desired enclosure or tuning knob directly to your personal list.
• Continue to use the shopping basket icon to add further items whilst browsing the website, such as suitable accessories, alternative enclosures or tuning knobs.
• You can view your shopping basket at any time by clicking the ‘i’ button on the right-hand side of your browser window >> select the shopping basket icon.
• Click the ‘Delete’ button to remove unwanted items from your list.

Quotation:

• Use the shopping basket to request a quote. Enter the desired quantities in the enquiry form. 
• Let us know what modifications or machining you require for your products in the shopping basket via the relevant selection window.
• If necessary, upload any additional specifications for your enquiry at the same time, e.g. sketches, etc.

Samples:

• If you would like to receive samples, simply tick the corresponding box on the order form. (Please note that, as a standard policy, we provide one sample per housing.)
• Use the “PDF Export” function to download your shopping basket as a PDF.
• Once you are satisfied with your shopping basket, click on “Continue to contact details >>”, then enter your contact details and click on “Submit enquiry”. You will receive your samples and/or quotation shortly.
  Note: You will automatically receive a copy of your “Online enquiry” in your registered email inbox.

Alternatively, you are welcome to contact us on +49 (0) 6281 404-00 to discuss your requirements directly with our sales team, or if you prefer to contact us by email, please send your enquiry directly to info@okw.com.

You can find the full instructions here >>

You can download our product drawings for individual enclosures and tuning knobs in 2D (PDF, DWG, DXF) and 3D (x_t, step, sat) formats. You can find out how to do this in the following blog article, which includes a video tutorial. Important to note: registration is required for drawing files and 3D models (except PDFs).

BLOG article: How do I download drawings?

A wide range of interesting documents is available for download in the following categories:

• Customer magazine INSIDE
• Installation instructions
• Publications, such as brochures and technical articles
• Certifications to ISO 9001:2015, Certification for “Hazardous substances posing a risk to the environment and human health”, Audit “Authorised Economic Operator AEO/F”

Go directly to the download page >>

The IP (Ingress Protection) rating in accordance with DIN EN 60529 / IEC 60529 classifies the degree of protection that enclosures offer in terms of safety against accidental contact and against the ingress of foreign bodies and water in harmful quantities. The IP protection classes specified for OKW enclosures refer to stock items without any machining or fitting of accessories.

The standard is defined by the International Electrotechnical Commission (IEC) and is based on a clear, user-friendly numbering system. This system establishes a uniform framework that manufacturers use to test and label the level of protection provided. Detailed descriptions of the individual ratings can be found in the table below.

View our comprehensive guide to IP protection ratings here (.pdf) >>

The UL 94 standard classifies the flammability of plastics for electronic devices in ascending order of fire resistance. This standard for the flammability of plastics is published by Underwriters Laboratories in the USA.

The standard classification is based on the burning rate, the extinguishing time, the occurrence of burning droplets and the afterglow duration after the flame is removed. Depending on the thickness of the standardised test specimen, several classifications are possible for each material – from the lowest (low flame retardancy) to the highest (high flame retardancy). Further information for you:

BLOG article: Flammability testing for plastics according to UL 94

BLOG article: Selection of standard enclosures made from flame-retardant plastic UL 94 V-0

An enclosure made from V-0 material in accordance with the UL 94 standard is recommended when fire safety is a concern. The V-0 classification indicates that the plastic has good self-extinguishing properties, thereby minimising the risk of fire spreading.

You can find detailed information and helpful tips in the following article:
BLOG article: Selection of standard enclosures made from flame-retardant plastic UL 94 V-0

These can be viewed and downloaded for the individual parts on the OKW website.

Select your preferred enclosure and/or tuning knob.

The material for the preferred product is already displayed on the product selection lists. Click on the information link (ABS, ASA, PC, etc.) for a specific product; a pop-up window will appear – click on the PDF link for material specifications.

Alternatively, go to the individual product page (the product number is the link).
Scroll down to the ‘Technical Data’ tab. Click on one or more links (e.g. ASA) in the ‘Material’ section to download PDF files.

Need help choosing the right material?

If you are still unsure which material is suitable for your specific application, we have prepared an overview with technical information (.pdf) for you. Click the following link: Material selection / Plastic properties / Recommendations for the use

On request, we machine our enclosures using machining processes to meet specific customer requirements. This includes, amongst other things, cut-outs for interfaces, cable entries and exits, displays, control elements and LEDs, recesses for labels/discs, threaded holes and much more.

New to our range of services:

• Reduction of the wall thickness on the inside to create partial backlighting of surfaces. Allows light from LEDs located behind the machined areas to shine through. Ideal for temperature or status indicators. The enclosure’s IP rating is maintained.
• Machining for push-button closures (male or female). Recommended for small enclosures such as BODY-CASE, MINITEC, ERGO-CASE, CONNECT, SOFT-CASE und MINI-DATA-BOX.

BLOG article: Mechanical machining of plastic enclosures

We have a modern in-house machine park comprising 3-axis CNC milling machines and the necessary equipment, such as jigs and high-quality tools (drills, milling cutters and much more), to enable us to machine the enclosures precisely to individual customer requirements.

Further benefits for customers resulting from in-house machining:

• The supply of enclosures, including machining, from a single source ensures quality and traceability. It also shortens delivery times and reduces CO₂ emissions.
• There is no risk of scrap (if caused by OKW itself). If the customer carries out the machining themselves, any scrap parts or test parts required for machine set-up must be ordered additionally.
• Specialist staff, decades of experience and expertise enable us to deliver all orders as quickly as possible and to the highest, reproducible quality standards.

BLOG article: Mechanical machining of plastic enclosures

Dimensions should be taken from the centre to reduce the tolerances of the enclosure parts; however, other reference points are also possible. In conjunction with our fixtures, we can achieve the following tolerances:

• ± 0.3 mm (± 0.01") for all dimensions relative to the reference edge of the enclosure
• all other non-toleranced dimensions are subject to the DIN ISO 2768m T1 standard.

If tighter tolerances are required, consultation is necessary. These special tolerances must be documented in a drawing. The smallest possible tolerance within the milled pattern is ± 0.05 mm (± 0.002") for plastic and ± 0.1 mm (± 0.004") for aluminium.

Housings made of thermosetting plastics are not suitable for machining due to the brittleness of the material. TPE parts can only be machined to a limited extent due to their rubber-like elasticity. Drilling holes in TPE parts is only possible upon special request. Please feel free to enquire with our team of experts: info@okw.com

Further information on radii, sharp edges, minimum bore diameters and residual wall thicknesses can be found in our machining data sheet. Click here to access the "Documents" tab on the "Customising" > "Machining" webpage for the information you require.

During the enquiry phase, we require a description of the machining, a dimensional sketch or a PDF drawing specifying the dimensions of the required cut-outs (length, width, Ø).

If an order is placed, a detailed dimensional drawing/sketch containing all dimensions required for machining (including clearance dimensions) is necessary. Alternatively, please send us 3D data, preferably in the file formats .sldprt, .step or .iges.

Further information can be found in our machining data sheet.
Click here to access the "Documents" tab on the "Customising" > "Machining" webpage for the information you require.

We paint the plastic enclosures and tuning knobs in your desired colour to enhance the visual or tactile appeal of your product or to match your individual branding. The colour should be specified according to RAL Classic. We are happy to check the availability of metallic or Pantone colours (form guide) on request.

We mix your colour using our own colour-mixing system from a range of 20 base colours. This guarantees high, consistent quality and short lead times. A colour deviation of up to ∆E = 2.5 is possible.

BLOG article: Coatings give every product its own character and aesthetic

OKW offers a wide range of coating options that meet both aesthetic and functional requirements. In terms of appearance, you can choose between different gloss levels (from matt to gloss), depending on whether you wish to reduce reflections or achieve a more sophisticated, modern look. The work is carried out in-house, ensuring high quality, full traceability and short lead times.

Further information can be found in our lacquering data sheet. Click here to access the "Documents" tab on the "Customising" > "Lacquering" webpage for the information you require, and also take a look at the pictures in the photo galery.

Screen printing, pad printing or digital printing – each process offers specific advantages in terms of durability, detail, flexibility and the degree of customisation. Choosing the right process can be crucial to the appearance and functionality of your product.

Screen printing:
Screen printing enables high ink coverage and is particularly suitable for large print runs. The process is frequently used for large-scale print designs and on flat surfaces.

Tampo printing:
Tampo printing is frequently used when precision and attention to detail are required. ‘Circular printing’ on rotary knobs, e.g. for scales, is also a very interesting option.

Digital printing:
Digital printing is increasingly being used when customised designs (images, colour gradients, sequential numbering, barcodes, etc.), prototypes and small batches are required.

Read our BLOG article: Screen printing, tampo printing and digital printing compared

Further information can be found in our data shees.
Click here to access the "Documents" tab on the "Customising" > "Printing" webpage for the information you require, and also take a look at the pictures in the photo gallery.

Many enclosures and tuning knobs from the OKW range can be laser-marked with a wide variety of information: text, logos, graphics, symbols, scales and markings. The process is particularly well suited to customised markings and labelling – including sequential numbering, barcodes, QR codes and DataMatrix codes, which need to be applied quickly and efficiently.

Laser marking of rubber-like materials, such as TPE, must first be checked for feasibility. Please enquire at: vertrieb@okw.com

Further information can be found in our laser marking data sheet.
Click here to access the "Documents" tab on the "Customising" > "Laser marking" webpage for the information you require, and also take a look at the pictures in the photo gallery.

Plastic parts in various shades of white, grey and black are particularly suitable for high-contrast marking. This process causes a colour change on the surface. Dark and light-coloured plastic parts turn grey at the points to be marked. Transparent parts that have been painted can be made transparent again by laser marking, depending on the paint colour.

To OKW’s laser marking service >>

Laser marking is suitable for a range of common housing materials, including ABS, ASA+PC, polycarbonate (PC), polyamide (PA/PA GF) and aluminium.
Good results may not be achievable with transparent plastics or high-gloss surfaces. We always check the material you have chosen and advise you if an alternative would be more suitable for better contrast.

To OKW’s laser marking service >>

Laser markings are extremely durable as they alter the surface of the material, unlike printing, where ink is applied. This means that, in practice, the laser marking is abrasion-resistant, water-resistant and smudge-proof, and does not wear away under normal use.

To OKW’s laser marking service >>

Download: Technical data sheet for laser marking (.pdf)

Decorative films can be produced quickly and easily, even in quantities as small as a single piece, for customised labelling and colour schemes. Decorative films are digitally printed. This offers a wide range of benefits and creative possibilities: complex layouts with colour gradients, the integration of technical information, sequential numbering or codes.

These films can be adapted to the respective user interface. They can include display windows, transparent areas and embossing for a wide range of functions, making them ideal for front panels and user interfaces.

Further information can be found in our decor foils data sheet.
Click here to access the "Documents" tab on the "Customising" > "Decor foils" webpage for the information you require, and also take a look at the pictures in the photo gallery.

Decorative films are produced using CMYK digital printing, whereby the printing colours can be matched to RAL Classic or Pantone colour specifications (Formula Guide). This ensures a perfect match with the brand identity or individual customer requirements.

However, as with any digital printing process, minor colour deviations of ΔE ≈ 2.5 may occur with each batch production. Special colours such as metallic colours, glossy shades, day-glow or afterglow colours cannot be printed using the digital printing process.

To the OKW service for decor foils >>

Many of our enclosures and tuning knobs can also be produced on request in special colours or, for safety-critical applications, in V-0 flame-retardant plastics.

Minimum order quantity for custom production:

• Enclosures: 200 pieces
• Tuning knobs: 500 pieces

For your desired colour, we have natural material extruded and dyed to a high standard of colour reproduction. Custom colour matching is possible according to samples, colour swatches, RAL or Pantone.

BLOG article: Personalise your enclosures and tuning knobs with custom colours

Technical data sheet for the special material V-0 (.pdf)

Technical data sheet for the special material ‘Colour’ (.pdf)

Without EMC shielding, plastic enclosures offer little or no protection against electromagnetic interference, as polymers are non-conductive and behave like insulators.
If the electronic device emits interference or is sensitive to external interference, EMC shielding is required to ensure reliable operation. And, of course, to meet EMC compliance requirements.

BLOG article: Safe and reliable electronics thanks to EMC protection

OKW achieves EMC shielding by applying a coating to the inside of the enclosure. This is carried out in a high-vacuum environment: the aluminium used, with a purity of 99.98%, is rapidly vaporised and deposited onto the plastic surface. The coating thickness is approximately 2.5 µm. The aluminium coating is generally characterised by good adhesion.

Further information can be found in our EMC shielding data sheet. Click here to access the "Documents" tab on the "Customising" > "EMC shielding" webpage for the information you require, and also take a look at the pictures in the photo gallery.

The aluminium coating forms a conductive layer, known as a Faraday cage. This blocks electromagnetic interference by reflecting and absorbing electromagnetic radiation. The effectiveness of the shielding depends on factors such as coating thickness and enclosure design, but coatings with a thickness of around 2.5 µm provide reliable shielding for many electronic applications.

EMC aluminium vapour deposition from OKW >>

Shielding against external interference radiation and increased internal interference emissions must be taken into account as part of the overall design of electronic devices. As shielding relies on electrical continuity, gaps at joints and openings must be avoided, as these could impair performance and increase susceptibility in subsequent applications.

Joints and connection points must always be regarded as critical, as they interrupt electrical continuity and can impair the effectiveness of the shielding. To counteract this, OKW offers conductive seals in various sizes ranging from ø 1.5 mm t, and up to ø 3 mm (ø 0.059" to ø 0.118"). These ensure contact between the individual housing parts and help to guarantee shielding performance.

EMC aluminium vapour coating from OKW >>

This can be the case, particularly at the joints between individual housing components. Standard seals can act as an EMC weak point, meaning that conductive seals are required to maintain the shielding performance. We would review both the EMC and IP requirements together to find the right solution.

EMC aluminium vapour deposition from OKW >>

Following consultation, OKW is happy to source components, carry out assembly, screw fastening or even the bonding of accessories. Of course, components for the assembly process can also be provided by the customer. For customised assembly and configuration, we offer a wide range of fasteners, such as threaded inserts, threaded studs, spacers, mounting domes, screws, etc.

Further information can be found in our assembly and installation data sheet. Click here to access the "Documents" tab on the "Customising" > "Installation / Assembly of accessories" webpage for the information you require, and also take a look at the pictures in the photo gallery.

Retrofitted components such as cable glands, feed-throughs, snap-on clips, mounting brackets and many others can compromise the seal in practice if they are not correctly specified and if the appropriate versions for the demanding application have not been selected. To counteract this, seals and components with integrated IP protection can be incorporated into the assembly process. To be on the safe side, we recommend having your finished end device certified.

About OKW’s assembly service >>

Tuning knobs are versatile and tried-and-tested control elements that primarily serve to control devices precisely, quickly and intuitively. Compared to touch surfaces, they offer the major advantage of direct haptic feedback. Particularly in sectors where gloves are worn on a daily basis (e.g. in medical technology), tuning knobs also offer a safety benefit where touchscreens reach their technical limits.

What are the advantages of tuning knobs:

• Precise setting and adjustment: Tuning knobs are used to set and regulate values with precision.
• Quick operation: Unlike touch buttons, which often require several clicks, a tuning knob allows for immediate and continuous adjustment of the desired setting.
• Intuitive feel: They provide tactile feedback, making the operation easier, whether wearing gloves or with wet hands.
• Controls in industry and technology: They are used, for example, to control machine terminals, laboratory and medical equipment, etc.
• Ergonomics and safety: They are easy to grip firmly and generally prevent accidental slipping.

About OKW's range of tuning knobs for electronic applications >>

Tuning knobs are versatile and suitable for various types of shaft ends typically found on potentiometers, encoders and switches.

Here are the most commonly supported shaft types:

• Flattened shafts (D-axis): Very common, often to DIN 41591 (e.g. 6/4.6 mm). These provide a positive-lock connection that prevents the knob from spinning through.
• Splined shafts: Typical for standard 6 mm potentiometers. These have fine teeth into which the tuning knob (often push-on style) engages.
• Round shafts (smooth): Suitable for tuning knobs with a side-mounted fixing screw (set screw) that is clamped onto the shaft.

OKW’s extensive range of tuning knobs >>

There are basically 3 types of mounting on the potentiometers:

• Collet mounting
  Very secure, often used for high-quality instrument knobs.
  View tuning knobs with collet mounting >>
• Push-on
  Ideal for knurled shafts, quick to fit, but require a tighter tolerance on the shaft.
  View push-on tuning knobs >>
• With lateral screw fixing
  For different operating requirements depending on the application.
  View control knobs with lateral screw >>

Knobs with collet or clamping fastenings offer excellent concentricity and a first-class feel – particularly in high-end devices. They distribute the clamping force evenly around the shaft, sit securely and do not come loose easily – provided, of course, that the correct tightening torque is used.

As with its enclosures, OKW offers a wide range of customisation services for its rotary knob range, which can be tailored to corporate design, ergonomic requirements or specific mechanical specifications.

For rotary knobs, these options include (depending on the selected range):

• mechanical machining,
• printing (e.g. of scales),
• laser marking,
• lacquering and
• assembly processes.

OKW carries out all work in-house to ensure quality and traceability.

Overview customising services >>

Tuning knobs intended for use in electronic devices sold in the EU and the UK must generally comply with the RoHS and REACH directives, particularly with regard to prohibited substances and material composition.

If required, download OKW’s RoHS and REACH declarations of conformity from the ‘Technical Data’ tab > ‘Standards’ section on individual product pages.
Direct link to the document: Certificate / Summary of dangerous substances, hazardous to environment and health (.pdf)

Controls and tuning knobs are a primary point of contact for the user. For this reason, the material, ease of use and smooth operation, and aesthetics have a significant impact on the perceived product quality. Tuning knobs that sit poorly on the shaft or controls that look cheap are misguided cost-cutting measures that could undermine confidence in an otherwise high-quality product.

What else can enhance the high-quality appearance of the devices?
OKW offers tuning knobs with LED lighting in its portfolio for this purpose. These effectively reinforce the high-quality feel of the device design and guide the user to the central control interface.

Tuning knobs with LED illumination from OKW >>