Fastenright thread forming screws for plastic (FasPlas) are designed for use on thermoplastic materials, and will slice through plastic with minimal stress and low installation torque. Some of the benefits, to mention just a few are that these thread covering caps are easy fitting, easy removal and easy handling. They feature an easy grip head to allow for fast and efficient screwing on and off of the application. The right way to assemble a threaded PVC joint-Schedule 40 or 80 is finger tight plus one to two turns-no more. Two turns past finger tight plus the stress of the system pressure is within the tensile strength of one-inch PVC. ([1,788 psi x 2] + 2,000 psi = 5,576 psi).

In addition to hydraulics, they’re also used to cap off tube and pipe ends. You’ll find them in automotive, pneumatic and engineering applications, providing protection to welding areas and studs for masking processes and preventing damage caused by mishandling. What are threaded plugs used for? And when you want to prevent or limit fluid leakage, a threaded hole plug with a seal or o-ring is ideal due to its precise fit. On threaded male PVC fittings each successive thread is slightly larger in diameter than the one before it. Female threads get successively smaller. This is called taper and the amount of taper is specified (1¾ degrees) in the American National Standard B2.1. All pipe manufacturers voluntarily follow these standards to assure their customers they are receiving quality materials. These metal screws require pre-drilled or moulded holes and most commonly have a 30° or 45° flank angle, although 60° angles are also available for specialist applications. For screwing into thinner materials, a selection of our FasPlas screws are available with trilobular heads, which lessen the risk of burst out.

PVC Fitting Thread Style

To cut glass, a notch is scratched into the surface. The notch produces a high stress concentration or stress riser, which is indicated by the red area in the diagram above. Applying a bending load will break the glass along the stress riser or notch. Don't wrap Teflon tape or Teflon paste or pipe dope to add bulk to or to lubricate the joint. Do use a sealant for threaded joints. Most plastics, including PVC, are notch sensitive. Glass, because it is a very notch sensitive material, is a very good example. Let’s face it: Screw threads were originally designed for metal parts, and were standardized long before plastic injection molding became mainstream. This has created a few challenges for plastic part designers. The first is that the classic, 60-degree V-style thread seen in the fastener aisle of your local hardware store is relatively shallow. This isn’t a problem when parts are made of strong, tough metal. But those made of plastic tend to strip more easily, especially on fine pitch threads or those the size of a pencil or smaller. That’s why Protolabs recommends that internal threads should be no smaller than 0.3 in. (7.6mm) in diameter, and recommends using the coarsest pitch possible (regardless of size) for your design. Using Undercuts for Molded Threads

To see why the highest loads are on the pitch diameter, we must see how the wedging action loads are distributed. Let’s use a 1 inch pipe thread for this example! Strain is the change in diameter for every revolution of the threaded joint, in this example the pitch diameter increases .0055 inches for each full turn. Since the pitch diameter at the end of the internal thread is 1.230 and the diameter increase of .0055 inch for each turn this yields a strain of .00447 inch/inch. Whereas, the change in pitch diameter on the outer wall of the fitting that measures 1.673 would be .00329 inch/inch Crank Handles Our crank handles are available in a variety of different styles and are ideal to use on machinery with rotating parts.A sealing compound must be compatible to plastics. Many brands of pipe sealant contain oils, solvents or carriers that can damage plastic. A proper sealant must be certified by the manufacturer to be harmless to the fitting material and to not contaminate fluid in the pipe. We offer a return period on all of our products to give you peace of mind, to view our policies and Some manufacturers produce Swing Joints with an alternate style of thread profile called "Buttress" threads. They promote the slanting notches of their threads as adding strength. The truth is these "Buttress" threads still have a "V" notch at the root of the thread profile that consequently make it sensitive to bending loads. The strength of these fittings is still substantially reduced. Finally, a sealing compound must not lubricate the joint to the point that over-tightening is encouraged. Several sealants on the market meet all these requirements.