Outstanding chemical resistance at elevated temperatures
- Virtually inert to most organics, acids and bases
- Usable up to 260°C / 500°F and tougher than PTFE
- Excellent electrical insulator
- High purity for sensitive pharmaceutical and food type applications
- PFA set screw features and benefits
PFA set screws made from perfluoroalkoxy alkanes (PFAs) are fluoropolymers with properties similar to polytetrafluoroethylene (PTFE). PFA's are known for being exceptionally corrosion resistant and inert at elevated temperatures. PFA screws are inert to most chemical environments including organics, acids, bases, mixed chemicals and hyrdofluoric acid. Additionally PFA set screws are bio-inert and will not leach into or contaminate sensitive pharmaceuticals or food based products.
Compared to other high performance polymer screws like PEEK or PVDF, PFA set screws offer the best all-around corrosion resistance especially at elevated temperatures. However the trade-off for its extraordinary corrosion resistance is its lower tensile strength compared to PVDF or PEEK screws.
PFA set screws are unique in that they have no screw head, meaning that they have no protruding part past the threaded shaft. They are thread only and are available with a socket or slotted driver insert at one end. Set screws are used to secure an object within or against another object. Typically they secure a rotating part such as a gear or shaft. PFA set screws are driven through a threaded hole in the rotating part until it is tight against the inner object, preventing from moving relative to the outer object. Set screws are available with various points depending on the application.
This is the most commonly used set screw and is identified by a cup-shaped indentation on one end. PFA cup points are typically used for a quick, semi-permanent or permanent applications where it is acceptable to cut the cup point edge of the screw.
A cone point is easily identifiable by its sharp cone-shaped point – just like an ice cream cone. PFA cone point set screws deliver the strongest clamping force due to the deep penetration of the point. As a result they are used for permanent assembly.
The cheapest and simplest of the set screw point styles, this screw has a flat surface on the bottom of the screw. This type is used when you need the ability to frequently change parts and require minimal shaft deformation.