Wixroyd Captive Screws 36681 - 36692
What is...
Wixroyd produce a wide range of fasteners designed for application, where it is important that fasteners are not separated from equipment (e.g. cover panels etc). This is now important to ensure that equipment complies with Machinery Directive 200642/EC - requiring that fasteners remain attached to fixed guards or equipment when guards are removed.
Our Captive Panel Screws are manufactured mainly from stainless steel (A2, AISI 303 grade), but they can also be produced in stainless steel (A4, AISI 316), aluminium, brass or zinc plated steel.
Materials
Coatings
Many finishes can be applied - black oxide finish, anodizing etc.
The main options are as follows:
| Finish | Notes |
| Black Chrome (MIL-C-1458B) | Black chrome is hard, non-reflective coating which is resistant to abrasion, heat and erosion. The black chrome surface is a dull, dark grey and may be waxed or oiled to darken surface. |
| Black Oxide Coating (MIL-C-13924B) | Black oxide is a uniform black coating for ferrous metals. Generally it is considered a decorative coating and provides only very limited corrosion protections under mild corrosion conditions. |
| Cadmium | Cadmium is a bright, silvery white plating. Supplementary treatments for type II can be golden, iridescent, amber, black or olive drab. |
| Passivate (QQ-P-35/MIL S-5OOSC) | Passivation is a process designed to remove foreign metals from the surface of stainless and corrosion resistant steels. |
| Phosphate Coating Ligth (TT-C-0D490B) | Phosphate coating is a light coating for use as a base paint. |
| Gold (MIL-G-45204B) | Yellow to orange colour depending on a proprietary process used. Will range from matt to bright finish depending on base metal. Good corrosion resistance and high tarnish resistance. |
| Nickel | Nickel is a corrosion protective plating for steel, zinc and zinc alloys as well as copper and copper alloys. |
| Zinc (QQ-Z-325C) | The primary use of chromate finishes on zinc is to retard or prevent formation of white corrosion products on zinc surfaces. |
| Schematic | Drive Types | Uses |
 | Hexagonal recess | Ideal for precision assembly. Most recommended where less surface area is available. |
 | Crosshead (Phillips®) | Provides good control in driving. Always use a driver bit of the proper size which is in good condition. |
 | Star Head (Torx®) | Positive-engaging, fast-locating method which transmits drive torque with less required downward pressure. Good fastening appearance. |
 | Slotted | Accepts standard blade screwdriver. Requires less downward pressure to drive parts than those with recessed openings. Use a proper fitting blade to minimise slippage. |
 | Security | These screws are impossible to remove without the special matching screw driver. |
Features
Ordering Options
36681 - Cap Head - hex. socket
36682 - Cap Head - hex. socket Security and Torx® options
36683 - Pan Head - Phillips®
Security and Torx® options
36684 - Countersunk - hex. socket
Security and Torx® options
36686 - Thin head thumb screw
36687 - Thumb screw
36691 - Threaded captive washers
36692 - Retainer flanges
General Guidance
One option to retain screws to panels are our Retaining Washers. Used in place of Retainer Flanges, Retaining Washers are simple but effective when used with our Captive Screws. The Captive Screws have a normal thread and a reduced diameter for the rest of the screw length.
The Retaining Washer has a small length of thread on the internal diameter and once screwed on to the Captive Screw is effectively captive.
Preparation
- Selection retainer based upon panel thickness
- Countersink panel
Applications
Screw the thin Retaining Washer onto the Captive Screw and the screw is therefore retained to the panel.
Installation
Mounting
- Insert flange
- Use ball bearing or punch to form flange on panel
The flange is then joined to the panel using either a simple ball bearing (or for higher volume parts a hand punch) to form the bottom of the flange into the countersink. This retains the flange to the sheet.
Retaining Flange secured onto panel using ball bearing or punch
Captive Screw Assembly
The Captive Screw or Bolt is then threaded onto the retainer flange. Once the thread length is through the initial shallow threaded portion of the retainer flange, it is then captive.
With any Captive Screw installation, it is important to ensure that there is enough space for the threaded portion to become disengaged from the female thread of the structure.
