GN653.2 Knurled Screws, Recessed Stud, for Loss Prevention
Knurled screws GN 653.2 are used when it is important to prevent any loss of the thumb screw. This is due to the d4 recessed portion of the stud.
These screws, particularly the stainless steel option, are ideal for use in the food industries, and their processing and packaging, where it is imperative that components are not lost. The stainless version is perfect for use in cleanroom environments, such as found in the medical and pharmaceutical industries, and they are also useful in situations where there are challenging conditions or where any lost components could not be easily recovered, such as sailing.
When using, instead of a typical tapped and bore hole, it is necessary to provide tapped bores with a thread d1 on each of the two elements to be assembled. Additionally, a clearance bore of d5 on one or both sides must be cut.
Depending on the design and required clamping length a1 - a3 of the component being attached, there are a number of assembly options as shown above.
Steel ST Tensile strength class 5 (500 N/mm²), visible face fine turned, black oxide finish
Stainless Steel NI AISI 303, visible face fine turned, matt shot-blasted