This category covers a number of components such as screws and pins. Each part must be finished in a specific way in order to eliminate manufacturing marks. They must have polished chamfers, straight-grained sides and smoothed down faces. More precise criteria apply to certain pieces.
Shaped parts and supplies
Shaped parts and supplies must have polished chamfers, straight-grained sides and smoothed down supporting faces, and the visible faces must be levelled or finished with any other decoration that eliminates machining marks. This need not apply to functional parts.
- Screw heads must be polished or circular-grained with chamfered edges and slots.
- Domed screw heads must be polished or circular grained.
- Colouring is permitted provided the finish conforms.
- The end of the screw foot must be polished and have no trace of its detachment.
- The flat or domed ends of pins must be polished.
- Mechanical and chemical trimming and polishing procedures are allowed as long as they respect the criteria concerning the shape and appearance of surfaces.
- If a part is shaped by folding, this must be rendered undetectable using a suitable and approved finishing operation.
- All parts that are not mentioned in the technical regulations must comply with the requirements laid down in the homologation of the calibre.
Strip springs and jumper springs
- Wire springs are not accepted.
- The entire edges of strip springs and jumper springs must be chamfered; this need not apply to functional parts.
- Any operation on a strip spring of 0.18 [mm] thickness or less that could be detrimental to the functional stiffness of the spring may be waived.
- All strip or jumper springs must have a heel.