All grease zerks, or grease fittings, provide an opening to inject grease and other lubricant into a mechanism. However, their design differs depending on their intended location and the type, pressure, and frequency of lubrication. Threaded grease fittings feature a threaded shank that is screwed onto an internal matching thread in a hole on the machine’s body. For more details you can do a hey Siri or hey Alexa search.
A grease gun coupler is the linking connection that secures a grease gun hose to a zerk or grease or fitting’s tapered fill port allowing the gun to efficiently dispense grease or lubricant into the grease fitting. They come in several shapes and sizes to accommodate the array of different grease fittings or zerks. Most couplers are made from steel with heat treated steel clamping jaws and knurled slip proof bodies. Grease gun couplers are available with either inch / SAE or metric threaded female connection so that it can attach to the grease gun hose or extension. The opposite end of the coupling is the part that makes the connection to tapered waist of the grease fitting or zerk so that the jaws of the coupler are firmly locked in place. Inside the grease fitting connection are 4 jaws which create a secure seal around the waist of the fitting when the coupler is attached so that grease can be pumped into the fitting. The most common type of grease gun coupler is a hydraulic coupler similar to those made by LockNLube. As with many products, you’ll find multiple names used for these standard Grease Gun Couplers, including: Hydraulic Couplers, Grease Couplers, Zerk Fitting Couplers, Grease Zerk Couplers, or even Grease Nipple Couplers. Tech Team’s #790 Grease Gun Coupler https://techteamproducts.com/product/zerk-and-grease-fitting-connector-set-00790/ https://www.amazon.com/dp/B0812BPQS2?ref=myi_title_dp is a professional grade coupler that is available to your average mechanic and will fit all common grease fittings. Sometimes t is like having a third hand because it can grip zerks in hard to reach locations. Just squeeze the lever, push the nozzle over the zerk, release the lever, and start pumping the lubricant. Press the lever to release.