Easy to assemble, simply slide the Ferrule over the tubing and finger tighten the nut. No need to flange your PTFE tubing! the 1/16" Ferrule and nut are rated at 1000 psi; the 1/8" Ferrule and nut are rated at 500 psi. Feature 1/4-28 threads. Flangeless fittings are easy to assemble. Slide the Ferrule over the tubing and fingertightenthe nut. Excellent chemical resistance. 1/8 inch fittings are rated to 500 psi; 1? 16 inch fittings are rated to 1000 psi. All fittings feature 1? 4-28 threads.