Typical applications for brass fittings include grease, fuels, LP and natural gas, refrigeration, instrumentation and hydraulic systems. Use with brass, bronze, copper, steel, aluminum and iron pipe. Midland Metal's brass fittings feature fair vibration resistance and an operating pressure up to 1200 PSI. The temperature range is -65°F to +250°F. These brass fittings are not lead free. Meets specifications and standards of ASA, ASME and SAE. Midland Metal's 28-174 Brass Slotted-Head Plug features a 1/8 in. thread size.